[ { "id": "https://authors.library.caltech.edu/records/nc59f-2jz76", "eprint_status": "archive", "datestamp": "2023-12-20 21:13:54", "lastmod": "2023-12-20 21:16:43", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bhattacharya-K", "name": { "family": "Bhattacharya", "given": "Kaushik" }, "orcid": "0000-0003-2908-5469" }, { "id": "Gavini-Vikram", "name": { "family": "Gavini", "given": "Vikram" }, "orcid": "0000-0002-9451-2300" }, { "id": "Ortiz-M", "name": { "family": "Ortiz", "given": "Michael" }, "orcid": "0000-0001-5877-4824" }, { "id": "Ponga-Mauricio", "name": { "family": "Ponga", "given": "Mauricio" }, "orcid": "0000-0001-5058-1454" }, { "id": "Suryanarayana-Phanish", "name": { "family": "Suryanarayana", "given": "Phanish" }, "orcid": "0000-0001-5172-0049" } ] }, "title": "Accurate Approximations of Density Functional Theory for Large Systems with Applications to Defects in Crystalline Solids", "ispublished": "unpub", "full_text_status": "public", "note": "
\u00a9 2023 The Author(s), under exclusive license to Springer Nature Switzerland AG.
\n\nWe are grateful to Phani Motamarri for sharing the unpublished results shown in Table 12.1. We acknowledge the help of Arpit Bhardwaj, Sambit Das and Xin Jing in running some of the DFT-FE and SQ simulations, and generating the corresponding figures. KB, MO and MP acknowledge the support of the Army Research Laboratory under Cooperative Agreement Number W911NF-12-2-0022. VG acknowledges the support of the U.S. Department of Energy, Office of Science through grants DE-SC0008637 and DE-SC0017380. VG also gratefully acknowledges the support of the Army Research Office through the DURIP grant W911NF1810242. PS acknowledges support of the U.S. Department of Energy, Office of Science through grant DE-SC0019410. The computations presented here were conducted on the Resnick High Performance Cluster at Caltech, the Great Lakes High Performance Cluster at the University of Michigan, the Oak Ridge Leadership Computing Facility, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory under contract DE-AC05-00OR22725, and the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, of the Army Research Laboratory, Department of Energy, or the U.S. Government. The U.S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation herein.
", "abstract": "This chapter presents controlled approximations of Kohn\u2013Sham density functional theory (DFT) that enable very large scale simulations. The work is motivated by the study of defects in crystalline solids, though the ideas can be used in other applications. The key idea is to formulate DFT as a minimization problem over the density operator, and to cast spatial and spectral discretization as systematically convergent approximations. This enables efficient and adaptive algorithms that solve the equations of DFT with no additional modeling, and up to desired accuracy, for very large systems, with linear and sublinear scaling. Various approaches based on such approximations are presented, and their numerical performance is demonstrated through selected examples. These examples also provide important insights into the mechanics and physics of defects in crystalline solids.
", "date": "2023-12-20", "date_type": "published", "publisher": "Springer", "place_of_pub": "Cham, Switzerland", "pagerange": "525-578", "isbn": "978-3-031-22339-6", "book_title": "Density Functional Theory: Modeling, Mathematical Analysis, Computational Methods, and Applications", "editors": { "items": [ { "id": "Canc\u00e8s-Eric", "name": { "family": "Canc\u00e8s", "given": "Eric" } }, { "id": "Friesecke-Gero", "name": { "family": "Friesecke", "given": "Gero" } } ] }, "official_url": "https://authors.library.caltech.edu/records/nc59f-2jz76", "funders": { "items": [ { "grant_number": "W911NF-12-2-0022" }, { "grant_number": "DE-SC0008637" }, { "grant_number": "DE-SC0017380" }, { "grant_number": "W911NF1810242" }, { "grant_number": "DE-SC0019410" }, { "grant_number": "DE-AC05-00OR22725" }, { "grant_number": "DE-AC02-05CH11231" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1007/978-3-031-22340-2_12", "pub_year": "2023", "author_list": "Bhattacharya, Kaushik; Gavini, Vikram; et el." }, { "id": "https://authors.library.caltech.edu/records/yf1k6-9nj40", "eprint_id": 121558, "eprint_status": "archive", "datestamp": "2023-08-20 16:39:32", "lastmod": "2023-10-20 15:38:22", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Donitz-Benjamin-P-S", "name": { "family": "Donitz", "given": "Benjamin P. S." } }, { "id": "Mages-Declan", "name": { "family": "Mages", "given": "Declan" }, "orcid": "0000-0002-2783-2144" }, { "id": "Tsukamoto-Hiroyasu", "name": { "family": "Tsukamoto", "given": "Hiroyasu" }, "orcid": "0000-0002-6337-2667" }, { "id": "Dixon-Peter", "name": { "family": "Dixon", "given": "Peter" } }, { "id": "Landau-Damon", "name": { "family": "Landau", "given": "Damon" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Bufanda-Erica", "name": { "family": "Bufanda", "given": "Erica" }, "orcid": "0000-0002-0406-8518" }, { "id": "Ingham-Michel-D", "name": { "family": "Ingham", "given": "Michel" }, "orcid": "0000-0001-5893-543X" }, { "id": "Castillo-Rogez-Julie-C", "name": { "family": "Castillo-Rogez", "given": "Julie" }, "orcid": "0000-0003-0400-1038" } ] }, "title": "Interstellar Object Accessibility and Mission Design", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2023. California Institute of Technology. Government sponsorship acknowledged. \n\nThis work is being carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under contract to NASA. Government sponsorship acknowledged.\n\nPublished - Interstellar_Object_Accessibility_and_Mission_Design.pdf
", "abstract": "Interstellar objects (ISOs) are fascinating and under-explored celestial objects, providing physical laboratories to understand the formation of our solar system and probe the composition and properties of material formed in exoplanetary systems. In this work, we investigate approaches to designing successful flyby missions to ISOs. We have generated trajec-tories to a series of synthetic representative ISOs, simulating a ground campaign to observe the target and resolve its state, and determining the cruise and close approach \u0394 V required for the encounter. We have developed novel deep learning-driven guidance and control algorithms to enable an accurate flyby of an ISO traveling at velocities over 60 km/s. In this paper, we discuss the accessibility of and mission design to ISOs with varying characteristics, including analysis of state covariance estimation over the course of cruise, handoffs from traditional navigation approaches to novel autonomous navigation for fast flyby regimes, and overall recommendations about preparing for the future in situ exploration of these targets.", "date": "2023-03", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "1-9", "id_number": "CaltechAUTHORS:20230526-663037000.22", "isbn": "978-1-6654-9032-0", "book_title": "2023 IEEE Aerospace Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230526-663037000.22", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/aero55745.2023.10115554", "primary_object": { "basename": "Interstellar_Object_Accessibility_and_Mission_Design.pdf", "url": "https://authors.library.caltech.edu/records/yf1k6-9nj40/files/Interstellar_Object_Accessibility_and_Mission_Design.pdf" }, "pub_year": "2023", "author_list": "Donitz, Benjamin P. S.; Mages, Declan; et el." }, { "id": "https://authors.library.caltech.edu/records/0n4k3-44808", "eprint_id": 121557, "eprint_status": "archive", "datestamp": "2023-08-20 16:39:27", "lastmod": "2023-10-20 15:38:19", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Veismann-Marcel", "name": { "family": "Veismann", "given": "Marcel" }, "orcid": "0000-0001-8106-6738" }, { "id": "Raffel-Jan", "name": { "family": "Raffel", "given": "Jan" } }, { "id": "Leipold-Malicia", "name": { "family": "Leipold", "given": "Malicia" } }, { "id": "Wanner-Julius", "name": { "family": "Wanner", "given": "Julius" } }, { "id": "Tosi-Luis-Phillipe", "name": { "family": "Tosi", "given": "L. Phillipe" }, "orcid": "0000-0002-0819-4765" }, { "id": "Izraelevitz-Jacob-S", "name": { "family": "Izraelevitz", "given": "Jacob" } }, { "id": "Devost-Matthew", "name": { "family": "Devost", "given": "Matthew" } }, { "id": "Young-Larry", "name": { "family": "Young", "given": "Larry" } }, { "id": "Touma-Thomas", "name": { "family": "Touma", "given": "Thomas" }, "orcid": "0000-0002-4921-2210" }, { "id": "Shah-Parthiv", "name": { "family": "Shah", "given": "Parthiv" } }, { "id": "Weiss-Adam-D", "name": { "family": "Weiss", "given": "Adam" }, "orcid": "0000-0003-0103-0335" }, { "id": "Reveles-Nicolas", "name": { "family": "Reveles", "given": "Nicolas" } }, { "id": "Ostoich-Chris", "name": { "family": "Ostoich", "given": "Chris" } }, { "id": "Raffel-Markus", "name": { "family": "Raffel", "given": "Markus" }, "orcid": "0000-0002-3340-9115" }, { "id": "Burdick-J-W", "name": { "family": "Burdick", "given": "Joel" }, "orcid": "0000-0002-3091-540X" }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "Morteza" }, "orcid": "0000-0003-0754-4193" }, { "id": "Delaune-Jeff", "name": { "family": "Delaune", "given": "Jeff" }, "orcid": "0000-0003-1509-4401" } ] }, "title": "Study of Rotor-Jetpack-Wind Aerodynamic Interaction for Mid-Air Helicopter Delivery on Mars", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2023 IEEE. \n\nThe research described in this paper was funded by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. \n\nThe authors thank the Center for Autonomous Systems and Technologies for providing the necessary resources as well as the facility for testing and Noel Esparza-Duran for supporting the team during the setup of the test-bench. \n\nPart of the research described in this paper was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). \u00a9 2022.", "abstract": "Mid-Air Helicopter Delivery (MAHD) is a new Entry, Descent and Landing (EDL) architecture for enabling future Martian helicopter-only missions (e.g., Mars Science Helicopter (MSH)), that offer much greater in situ mobility compared to traditional rover missions at lower cost. This EDL concept utilizes a delivery jetpack to slow down the rotorcraft free fall after separation from the parachuting backshell, thus avoiding unfavorable rotorcraft descent aerodynamics, and provides suitable aerodynamic conditions for helicopter take-off in mid air. While Martian rotorcraft operation has been successfully demonstrated by the Ingenuity system, the mid-air helicopter take-off from a self-propelled jetpack platform has been identified as one of the critical aspects of this EDL strategy. This paper presents the development of an experimental sub-scale test-bench to assess the aerodynamic interactions between the MSH, a jetpack analogue system, and the wind to evaluate the technical feasibility of MAHD. Aerodynamic measurements and various qualitative and quantitative flow visualizations were performed in a (1 atm / 1 g) environment and compared to computational fluid dynamics (CFD) simulation for validation. We also demonstrate in-flight capabilities of wind sensing as well as active trimming of the rotorcraft under relative crosswinds using an integrated force-torque sensor to be placed between rotorcraft and jetpack.", "date": "2023-03", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "1-16", "id_number": "CaltechAUTHORS:20230526-663030000.20", "isbn": "978-1-6654-9032-0", "book_title": "2023 IEEE Aerospace Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230526-663030000.20", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech", "grant_number": "80NM0018D0004" } ] }, "local_group": { "items": [ { "id": "Center-for-Autonomous-Systems-and-Technologies-(CAST)" }, { "id": "GALCIT" } ] }, "doi": "10.1109/aero55745.2023.10115979", "pub_year": "2023", "author_list": "Veismann, Marcel; Raffel, Jan; et el." }, { "id": "https://authors.library.caltech.edu/records/6nkzy-hw644", "eprint_id": 121563, "eprint_status": "archive", "datestamp": "2023-08-20 16:39:39", "lastmod": "2023-10-23 15:39:25", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Choi-Changrak", "name": { "family": "Choi", "given": "Changrak" }, "orcid": "0000-0001-8869-6839" }, { "id": "Nakka-Yashwanth-K", "name": { "family": "Nakka", "given": "Yashwanth Kumar" }, "orcid": "0000-0001-7897-3644" }, { "id": "Rahmani-Amir", "name": { "family": "Rahmani", "given": "Amir" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Resilient Multi-Agent Collaborative Spacecraft Inspection", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2022 California Institute of Technology. \n\nThis work was supported by the Jet Propulsion Laboratory's Research and Technology Development (RTD) program. Part of the research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.\n\nPublished - Resilient_Multi-Agent_Collaborative_Spacecraft_Inspection.pdf
", "abstract": "Distributed spacecraft systems (DSS) involving SmallSats in low Earth orbit are gaining significant interest both for Earth observation and on-orbit servicing purposes. However, the miniaturized low-cost components of SmallSats are susceptible to faults, making DSS prone to failures that are detrimental to its overall system performance. In this work, we address the problem of providing resiliency to potential failures for a fleet of spacecraft that are performing on-orbit inspection. The proposed methodology guarantees graceful degradation of the inspection performance even against the worst-case failures, through selection and assignment of formation orbits that are resilient to it. We define quantitative metric to measure collaborative inspection performance, taking into consideration both the information gain and control cost, and formulate worst-case failure of \u2113-spacecraft that maximally undermine it. The main algorithm searches through the space of formation orbits, sampling through a set of orbits with evaluation of its inspection performance in the presence of worst-case failures. The algorithms are designed to be computationally efficient and have linear scaling to the number of spacecraft and orbits, making it applicable to real-time planning for spacecraft swarms. The effectiveness of the proposed approach is validated through simulation experiments on a design reference mission involving five CubeSats inspecting a target spacecraft in low Earth orbit.", "date": "2023-03", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "id_number": "CaltechAUTHORS:20230526-663062000.31", "isbn": "9781665490320", "book_title": "2023 IEEE Aerospace Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230526-663062000.31", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "JPL Research and Technology Development Fund" }, { "agency": "NASA/JPL/Caltech" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/aero55745.2023.10115886", "primary_object": { "basename": "Resilient_Multi-Agent_Collaborative_Spacecraft_Inspection.pdf", "url": "https://authors.library.caltech.edu/records/6nkzy-hw644/files/Resilient_Multi-Agent_Collaborative_Spacecraft_Inspection.pdf" }, "pub_year": "2023", "author_list": "Choi, Changrak; Nakka, Yashwanth Kumar; et el." }, { "id": "https://authors.library.caltech.edu/records/w45qe-ee975", "eprint_id": 120466, "eprint_status": "archive", "datestamp": "2023-08-20 09:02:54", "lastmod": "2023-10-23 15:13:28", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Reddy-Narravula-Harshavardhan", "name": { "family": "Reddy", "given": "Narravula Harshavardhan" }, "orcid": "0000-0003-3897-8162" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Dynamics of the Caltech SSPP deployable structures: structure\u2013mechanism interaction and deployment envelope", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2023 by Narravula Harshavardhan Reddy, and Sergio Pellegrino. \n\nThis research was funded by the Space Solar Power Project at Caltech.\n\nThe authors thank Dr. Terry Gdoutos and Alan Truong for their help with CAD modeling and building the test structure;\nNoel Esparza-Duan, Michael O'Connell, Dr. Guanya Shi, Uba K. Ubamanayu, and George Popov for their help with\nmotion capture experiments; and Dr. Antonio Pedivellano for advice on simulation models.\n\nAccepted Version - 2023_Harsha-paper_SMALL.pdf
", "abstract": "The Caltech Space Solar Power Project has been developing ultralight deployable space structures consisting of thin-shell composite strips that support photovoltaic and RF elements. These modular, square structures can potentially be scaled to tens of meters in size. This paper studies the interaction between the deployment dynamics of the structure and the deployment mechanism, both experimentally and numerically. Instead of considering a full structure, a quadrant is considered to reduce the number of components and to better focus on the main parameters that affect the deployment behavior. Outcomes of this research will not only benefit the Caltech project but will also contribute to the design of future lightweight deployable space structures that undergo unconstrained dynamic deployment.", "date": "2023-01-23", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "id_number": "CaltechAUTHORS:20230327-902809000.10", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230327-902809000.10", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Space Solar Power Project" } ] }, "other_numbering_system": { "items": [ { "id": "2023-2065", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Space-Solar-Power-Project" } ] }, "doi": "10.2514/6.2023-2065", "primary_object": { "basename": "2023_Harsha-paper_SMALL.pdf", "url": "https://authors.library.caltech.edu/records/w45qe-ee975/files/2023_Harsha-paper_SMALL.pdf" }, "pub_year": "2023", "author_list": "Reddy, Narravula Harshavardhan and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/v271v-hbb79", "eprint_id": 120471, "eprint_status": "archive", "datestamp": "2023-08-20 08:58:08", "lastmod": "2023-10-23 15:30:52", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ubamanyu-Uba-K", "name": { "family": "Ubamanyu", "given": "Uba K." }, "orcid": "0000-0002-3679-6173" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Nonlinear Behavior of IM7 Carbon Fibers in Compression Leads to Bending Nonlinearity of High-Strain Composites", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2023 by Uba K Ubamanyu and Sergio Pellegrino. \n\nThe authors acknowledge financial support from the Space Solar Power Project at Caltech. The authors are grateful for the help of Rebecca Gallivan, Widianto Moestopo, Thomas Tran, and Wenxin Zhang with single fiber direct compression experiments, and Professor Julia Greer for providing access to her experimental facilities and Alexander Wen for helpful discussions and suggestions. Test materials for this study were provided by Patz Materials & Technology.\n\nAccepted Version - 2023_Nonlinear_behavior_of_IM7_carbon_fibers_Scitech.pdf
", "abstract": "This paper presents an experimental characterization of carbon fibers under compression and the influence of their nonlinear behavior on the bending nonlinearity of high-strain composites (HSC). The study is focused on HexTow IM7, a pan-based carbon fiber compressed under in-situ scanning electron microscopic (SEM) imaging. The sample preparation and experimental procedure of both single fiber direct compression tests and column bending tests of HSC samples are presented. Nonlinearity at the individual fiber level could not be observed due to the limitations of the load cell in the single fiber direct compression experiment. Using the column bending tests, a shift in the neutral axis due to the nonlinear compression behavior of fibers is observed.", "date": "2023-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2023-0580", "id_number": "CaltechAUTHORS:20230327-902858000.18", "isbn": "978-1-62410-699-6", "book_title": "AIAA SCITECH 2023 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230327-902858000.18", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Space Solar Power Project" } ] }, "other_numbering_system": { "items": [ { "id": "2023-0580", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Space-Solar-Power-Project" } ] }, "doi": "10.2514/6.2023-0580", "primary_object": { "basename": "2023_Nonlinear_behavior_of_IM7_carbon_fibers_Scitech.pdf", "url": "https://authors.library.caltech.edu/records/v271v-hbb79/files/2023_Nonlinear_behavior_of_IM7_carbon_fibers_Scitech.pdf" }, "pub_year": "2023", "author_list": "Ubamanyu, Uba K. and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/kbws5-7ar77", "eprint_id": 120467, "eprint_status": "archive", "datestamp": "2023-08-20 08:57:53", "lastmod": "2023-10-23 15:30:37", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Marshall-Michael-A", "name": { "family": "Marshall", "given": "Michael A." }, "orcid": "0000-0002-4259-2484" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Slew Maneuver Constraints for Agile Flexible Spacecraft", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2023 by Michael A. Marshall and Sergio Pellegrino. \n\nThe authors thank Antonio Pedivellano for help in developing the high-fidelity Abaqus finite element model used in the homogenization procedure mentioned in Sec. V. The authors likewise thank Dan Scharf, W. Keats Wilkie, and Jay Warren for the helpful comments and insightful discussions regarding this work. This work benefited from ideas and discussions with Mike Paul Hughes and the other participants at the \"Non-Nuclear Exploration of the Solar System\" workshop organized by the W. M. Keck Institute for Space Studies in April 2021. \n\nM. A. Marshall was supported by a NASA Space Technology Research Fellowship. Financial support from the California Institute of Technology (Caltech) Space Solar Power Project is also gratefully acknowledged.\n\nAccepted Version - 2023_Slew_maneuver_constraints_SciTech.pdf
", "abstract": "Traditional spacecraft design paradigms rely on stiff bus structures with comparatively flexible appendages. More recent trends, however, trade deployed stiffness for packaging efficiency to stow apertures with larger areas inside existing launch vehicles. By leveraging recent advances in materials and structures, these spacecraft may be up to several orders of magnitude lighter and more flexible than the current state-of-the-art. Motivated by the goal of achieving agility despite structural flexibility, this paper proposes a quantitative method for determining structure-based performance limits for maneuvering flexible spacecraft. It then uses a geometrically nonlinear flexible multibody dynamics model of a representative very flexible spacecraft to verify this method. The results demonstrate that, contrary to common assumptions, other constraints impose more restrictive limits on maneuverability than the dynamics of the structure. In particular, it is shown that the available attitude control system momentum and torque are often significantly more limiting than the compliance of the structure. Consequently, these results suggest that there is an opportunity to design less-conservative, higher-performance space systems that can either be maneuvered faster, assuming suitable actuators are available, or built using lighter-weight, less-stiff architectures that move the structure-based performance limits closer to those of the rest of the system.", "date": "2023-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2023-1883", "id_number": "CaltechAUTHORS:20230327-902813000.11", "isbn": "978-1-62410-699-6", "book_title": "AIAA SCITECH 2023 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230327-902813000.11", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA Space Technology Research Fellowship" }, { "agency": "Space Solar Power Project" } ] }, "other_numbering_system": { "items": [ { "id": "2023-1883", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Space-Solar-Power-Project" } ] }, "doi": "10.2514/6.2023-1883", "primary_object": { "basename": "2023_Slew_maneuver_constraints_SciTech.pdf", "url": "https://authors.library.caltech.edu/records/kbws5-7ar77/files/2023_Slew_maneuver_constraints_SciTech.pdf" }, "pub_year": "2023", "author_list": "Marshall, Michael A. and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/ee50k-ns830", "eprint_id": 120470, "eprint_status": "archive", "datestamp": "2023-08-20 08:58:03", "lastmod": "2023-10-23 15:31:01", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ballouz-Eric", "name": { "family": "Ballouz", "given": "Eric" } }, { "id": "Lopez-Doriga-Barbara", "name": { "family": "Lopez-Doriga", "given": "Barbara" } }, { "id": "Dawson-Scott-T-M", "name": { "family": "Dawson", "given": "Scott T. M." }, "orcid": "0000-0002-0020-2097" }, { "id": "Bae-Hyunji-Jane", "name": { "family": "Bae", "given": "Hyunji Jane" }, "orcid": "0000-0001-6789-6209" } ] }, "title": "Wavelet-based resolvent analysis for statistically-stationary and temporally-evolving flows", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2023 by Eric Ballouz, Barbara Lopez-Doriga, Scott T. M. Dawson, H. Jane Bae.", "abstract": "This work introduces a formulation of resolvent analysis that uses wavelet transforms rather than Fourier transforms in time. This allows resolvent analysis to be extended to turbulent flows with non-stationary means in addition to statistically-stationary flows. The optimal resolvent modes for this formulation correspond to the potentially time-transient structures that are most amplified by the linearized Navier-Stokes operator. We validate this methodology for turbulent channel flow and show that the wavelet-based and Fourier-based resolvent analyses are equivalent for statistically-stationary flows. We then apply the wavelet-based resolvent analysis to study the transient growth mechanism in the buffer layer of a turbulent channel flow by windowing the resolvent operator in time and frequency. The method is also applied to temporally-evolving parallel shear flows such as an oscillating boundary layer and three-dimensional channel flow, in which a lateral pressure gradient perturbs a fully-developed turbulent flow in a channel.", "date": "2023-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2023-0676", "id_number": "CaltechAUTHORS:20230327-902843000.16", "isbn": "978-1-62410-699-6", "book_title": "AIAA SCITECH 2023 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230327-902843000.16", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2023-0676", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2023-0676", "pub_year": "2023", "author_list": "Ballouz, Eric; Lopez-Doriga, Barbara; et el." }, { "id": "https://authors.library.caltech.edu/records/qahtr-awd39", "eprint_id": 120465, "eprint_status": "archive", "datestamp": "2023-08-20 08:57:48", "lastmod": "2023-10-23 15:30:40", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Wen-Alexander", "name": { "family": "Wen", "given": "Alexander" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Launch Vibration Damping Using Slip in Pretensioned Coils", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2023 by Alexander Wen, Sergio Pellegrino. \n\nThe authors acknowledge financial support from the Space Solar Power Project at Caltech.\n\nAccepted Version - 2023_Launch_Vibration_Damping_Scitech.pdf
", "abstract": "Vibration management is important for the survivability of structures during launch, and is particularly challenging for large deployable space structures. Adding damping to a structure reduces the overall level of response excitation, which increases survivability. Structural damping occurs through the dissipation of energy during vibration. One such energy dissipation mechanism that can be utilized to increase damping is friction, such as the friction between slipping layers of a wound roll. In this paper, we study the vibration response of a structure, which has a pre-tensioned coil wound around it. Here, the damping is provided by friction between slipping layers in the pre-tensioned coil. An experiment is performed on a small-scale setup to evaluate the feasibility of this approach by measuring the frequency response and damping under different winding tensions. The same setup is used to measure layer slip during vibration, using a high speed camera and tracking targets to identify the regions with the largest slip, indicating higher contribution to energy dissipation. To confirm understanding of the damping mechanism, a 3D finite-element simulation is created in an attempt to capture the variation in frequency response and locations of slip with winding tension measured experimentally.", "date": "2023-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2023-2066", "id_number": "CaltechAUTHORS:20230327-902798000.8", "isbn": "978-1-62410-699-6", "book_title": "AIAA SCITECH 2023 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230327-902798000.8", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2023-2066", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Space-Solar-Power-Project" } ] }, "doi": "10.2514/6.2023-2066", "primary_object": { "basename": "2023_Launch_Vibration_Damping_Scitech.pdf", "url": "https://authors.library.caltech.edu/records/qahtr-awd39/files/2023_Launch_Vibration_Damping_Scitech.pdf" }, "pub_year": "2023", "author_list": "Wen, Alexander and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/dff1x-rwj64", "eprint_id": 120477, "eprint_status": "archive", "datestamp": "2023-08-20 08:58:27", "lastmod": "2023-10-23 15:31:10", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kennedy-Aaron", "name": { "family": "Kennedy", "given": "Aaron" } }, { "id": "Penty-Geraets-Rowland-T", "name": { "family": "Penty-Geraets", "given": "Rowland" } }, { "id": "James-Christopher-M", "name": { "family": "James", "given": "Christopher M." } }, { "id": "Thompson-Matthew", "name": { "family": "Thompson", "given": "Matthew" } }, { "id": "Morgan-Richard-G", "name": { "family": "Morgan", "given": "Richard G." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "Joanna M." }, "orcid": "0000-0003-3129-5035" }, { "id": "Zander-Zander", "name": { "family": "Zander", "given": "Fabian" }, "orcid": "0000-0003-0597-9556" }, { "id": "McGilvray-Matthew", "name": { "family": "McGilvray", "given": "Matthew" }, "orcid": "0000-0001-9873-7737" } ] }, "title": "Measurements of Hypersonic Double Cone Flows with Shock Wave/Boundary Layer Interactions in the X3 Expansion Tunnel", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2023 by University of Oxford. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.\n\nI would like to give a huge thank you to Richard Morgan and Matthew Thompson from the University of Queensland\nfor vital support for this campaign particularly with condition development and data processing. In addition I would also\nlike to thank the staff at DST for hosting me and the stellar support they provided throughout this campaign, without\nwhich, this would not have been possible.\n\nAccepted Version - Kennedy_et_al_2023_Measurements_hypersonic_double.pdf
", "abstract": "This paper presents the results from a series of hypersonic double cone experiments, conducted in the X3 expansion tunnel at the University of Queensland (UQ). The model was previously used and produced at California Institute of Technology (Caltech) and is a scaled model of the double cone model used by the Calspan-University of Buffalo Research Center (CUBRC). The data presented is a full transient set of surface heat flux, and surface pressure measurements along the axial length of the model as well as a full suite of tunnel data. These aim to help characterize the flow over the geometry by providing surface conditions, an accurate location of the boundary layer separation, the flow reattachment points and the general structure of the shockwave boundary layer interaction. The geometry of the X3 facility is also provided to give a more complete picture of the test conditions, an important consideration for numerical models. The outcome of this paper is to provide the most detailed experimental data to date and improve validation attempts of existing non-equilibrium thermochemistry codes.", "date": "2023-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2023-0271", "id_number": "CaltechAUTHORS:20230327-902938000.30", "isbn": "978-1-62410-699-6", "book_title": "AIAA SCITECH 2023 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230327-902938000.30", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2023-0271", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2023-0271", "primary_object": { "basename": "Kennedy_et_al_2023_Measurements_hypersonic_double.pdf", "url": "https://authors.library.caltech.edu/records/dff1x-rwj64/files/Kennedy_et_al_2023_Measurements_hypersonic_double.pdf" }, "pub_year": "2023", "author_list": "Kennedy, Aaron; Penty-Geraets, Rowland; et el." }, { "id": "https://authors.library.caltech.edu/records/r7hny-5r270", "eprint_id": 120474, "eprint_status": "archive", "datestamp": "2023-08-20 08:58:17", "lastmod": "2023-10-23 15:30:49", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hasanyan-Armanj-D", "name": { "family": "Hasanyan", "given": "Armanj D." }, "orcid": "0000-0003-3676-9439" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Modeling of Damage in Coilable Composite Shell Structures", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2023 by Armanj Hasanyan, Sergio Pellegrino.", "abstract": "Coilable composite shell structures, composed of ultra-thin laminates, are ideal for deployable space structures applications. Their ability to be flattened and coiled for packaging, and deployed in their operational configuration makes them suitable for many space missions. Due to the complex states of stresses that occur in a composite shell during these processes (coiling, stowage, and deployment), material failure may be induced. This in turn would negatively affect the deployment, cause shape distortions, reduce the stiffness of the shell, or even lead to catastrophic failure of the mission. Therefore, predicting the failure modes and mechanisms of ultra-thin laminates at the structural scale is critical for design and certification purposes. However, this is often complicated by the complex microstructure and the multiple length-scales (micro and meso) associated with composites. This study presents a finite element model with progressive damage that effectively captures the ply failure modes. This is done through a damage constitutive model, where local cracks in the shell are smeared within a finite element. The fracture properties of interest are experimentally measured and incorporated into the model. The salient features of the model needed to capture failure are identified by comparing the simulation results with experiments. This is achieved by analyzing the coiling of a TRAC longeron shell structure.", "date": "2023-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2023-0364", "id_number": "CaltechAUTHORS:20230327-902890000.24", "isbn": "978-1-62410-699-6", "book_title": "AIAA SCITECH 2023 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230327-902890000.24", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2023-0364", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2023-0364", "pub_year": "2023", "author_list": "Hasanyan, Armanj D. and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/e9wva-yw491", "eprint_id": 120463, "eprint_status": "archive", "datestamp": "2023-08-20 08:57:43", "lastmod": "2023-10-23 15:30:31", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Allen-Brayden", "name": { "family": "Aller", "given": "Brayden" }, "orcid": "0000-0002-5258-4154" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" }, { "id": "Kinkaid-Nathan", "name": { "family": "Kinkaid", "given": "Nathan" } }, { "id": "Mejia-Ariza-Juan", "name": { "family": "Mejia-Ariza", "given": "Juan" } }, { "id": "Otis-Richard-A", "name": { "family": "Otis", "given": "Richard" } }, { "id": "Chan-Patrick-Hon-Man", "name": { "family": "Chan", "given": "Patrick Hon Man" } }, { "id": "Pena-Francisco", "name": { "family": "Pena", "given": "Francisco" }, "orcid": "0000-0003-2060-0428" } ] }, "title": "Strain Measurement in Coilable Thin Composite Shells with Embedded Fiber Bragg Grating Sensors", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2023 by Brayden Aller, Sergio Pellegrino, Nathan Kinkaid, Juan Mejia-Ariza, Richard Otis, Patrick Hon Man Chan and Francisco Pena. \n\nThe research was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). Support from the Caltech Space Solar Power Project is acknowledged. The authors would also like to acknowledge the contribution of Uba K. Ubamanyu for his input on the experimental setup used in this work.\n\nAccepted Version - 2023_Strain_measurement_SciTech.pdf
", "abstract": "Progress towards the use of ultra-thin fiber Bragg grating sensors for the in-situ strain measurement of coilable thin composite shells is presented. The first part of this work presents the manufacturing procedure used in the construction of these composite shells with embedded sensors. The second part of this work investigates how embedded ultra-thin fiber Bragg grating sensors affect the bending stiffness and failure curvature of these laminates through the use of the column bending test. The influence of the embedded sensors on the failure of these laminates is further investigated through \u03bcCT imaging after failure.", "date": "2023-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2023-2399", "id_number": "CaltechAUTHORS:20230327-902775000.4", "isbn": "978-1-62410-699-6", "book_title": "AIAA SCITECH 2023 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230327-902775000.4", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech", "grant_number": "80NM0018D0004" }, { "agency": "Space Solar Power Project" } ] }, "other_numbering_system": { "items": [ { "id": "2023-2399", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Space-Solar-Power-Project" } ] }, "doi": "10.2514/6.2023-2399", "primary_object": { "basename": "2023_Strain_measurement_SciTech.pdf", "url": "https://authors.library.caltech.edu/records/e9wva-yw491/files/2023_Strain_measurement_SciTech.pdf" }, "pub_year": "2023", "author_list": "Aller, Brayden; Pellegrino, Sergio; et el." }, { "id": "https://authors.library.caltech.edu/records/wpvzt-dt003", "eprint_id": 120462, "eprint_status": "archive", "datestamp": "2023-08-20 08:57:37", "lastmod": "2023-10-23 15:30:34", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Finch-Peter-M", "name": { "family": "Finch", "given": "Peter M." }, "orcid": "0000-0002-6975-6047" }, { "id": "Schwartz-Tal", "name": { "family": "Schwartz", "given": "Tal" }, "orcid": "0000-0002-5022-450X" }, { "id": "Granowitz-Zev-N", "name": { "family": "Granowitz", "given": "Zev N." }, "orcid": "0000-0001-8882-6752" }, { "id": "Yu-Wesley-M", "name": { "family": "Yu", "given": "Wesley M." }, "orcid": "0000-0002-1133-3199" }, { "id": "Gross-Thomas", "name": { "family": "Gross", "given": "Thomas" } }, { "id": "Strand-Christopher-L", "name": { "family": "Strand", "given": "Christopher L." }, "orcid": "0000-0002-4112-6668" }, { "id": "Schwartzentruber-Thomas-E", "name": { "family": "Schwartzentruber", "given": "Thomas E." }, "orcid": "0000-0001-9064-2346" }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "Joanna M." }, "orcid": "0000-0003-3129-5035" }, { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "Hans G." }, "orcid": "0000-0002-4903-8419" }, { "id": "Hanson-Ronald-K", "name": { "family": "Hanson", "given": "Ronald K." }, "orcid": "0000-0002-8030-5327" } ] }, "title": "Near-Body Measurements in Hypersonic Wedge Flows in the T5 Reflected Shock Tunnel by Tunable Diode Laser Absorption Spectroscopy", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2023 by Peter M. Finch.", "abstract": "We report on spectroscopic measurements of nitric oxide (NO) rotational and vibrational temperatures and concentration in the hypersonic flow fields around two symmetric wedge test models in the Caltech T5 reflected shock tunnel. Three quantum cascade lasers (QCLs), targeting 13 distinct quantum rovibrational transitions of NO, probed the T5 flows at a measurement rate of 50 kHz. Via tunable diode laser absorption spectroscopy (TDLAS), absorption from these rovibrational transitions permitted the path-averaged inferences of temperature and NO concentration both in front of and behind the shocks around the test articles. The fractional proportion of laser absorption in front and behind the shocks was also determined, enabling the measurement of shock locations at several lines of sight in the flow. Two different symmetric wedge test articles were utilized, one characterized by a wedge angle of 48o, and the other 38o. Three different T5 flow conditions were interrogated, a M = 5.5, \u223c8 MJ/kg stagnation enthalpy case, a M = 5.3, \u223c11 MJ/kg stagnation enthalpy case, and a M = 4.9, \u223c18 MJ/kg stagnation enthalpy case. Beam locations were specified relative to the wedge using alignment fins, Cartesian grids of holes which attached rigidly to the model endspans during alignment. The optical configuration allowed for independent characterization of the freestream and post-shock regions. Freestream measurements demonstrate general temperature and NO density decline over the duration of test time, typical of what has been previously measured in T5. Post-shock measurements demonstrate thermal equilibrium at elevated temperatures and high NO densities on the upstream sides of the wedges. Past the vertices of the wedges, post-shock measurements are colder, with thermal non-equilibrium sometimes detected.", "date": "2023-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2023-2518", "id_number": "CaltechAUTHORS:20230327-902761000.2", "isbn": "978-1-62410-699-6", "book_title": "AIAA SCITECH 2023 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230327-902761000.2", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2023-2518", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2023-2518", "pub_year": "2023", "author_list": "Finch, Peter M.; Schwartz, Tal; et el." }, { "id": "https://authors.library.caltech.edu/records/4nbh5-6ke96", "eprint_id": 120475, "eprint_status": "archive", "datestamp": "2023-08-20 08:58:20", "lastmod": "2023-10-23 15:30:58", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Paquin-Laura-A", "name": { "family": "Paquin", "given": "Laura A." }, "orcid": "0000-0002-0218-9666" }, { "id": "Laurence-Stuart-J", "name": { "family": "Laurence", "given": "Stuart J." }, "orcid": "0000-0001-8760-8366" }, { "id": "Hameed-Ahsan", "name": { "family": "Hameed", "given": "Ahsan" }, "orcid": "0000-0001-9563-3959" }, { "id": "Parziale-Nicholaus-J", "name": { "family": "Parziale", "given": "Nick J." }, "orcid": "0000-0001-9880-1727" }, { "id": "Yu-Wesley-M", "name": { "family": "Yu", "given": "Wesley M." }, "orcid": "0000-0002-1133-3199" }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "Joanna M." }, "orcid": "0000-0003-3129-5035" } ] }, "title": "Characterization of Transitional, High-Enthalpy Boundary Layers on a Slightly-Blunted Cone. Part I: Schlieren Imaging", "ispublished": "unpub", "full_text_status": "public", "note": "This material is declared a work of the U.S. Government and is not subject to copyright protection in the United States.", "abstract": "This paper presents an experimental investigation into the boundary-layer stability of a slender cone in hypervelocity flow within the T5 reflected-shock tunnel. Schlieren imaging was utilized to characterize the frequency content and disturbance structures experienced within the boundary layer of a 5\u25e6 cone in a Mach-5 freestream with high reservoir enthalpy, 8-10 MJ/kg. The effects of varying freestream Reynolds number and nose bluntness were examined. Second-mode frequency peaks between 1200-1300 kHz were identified in all cases, but they persisted over a longer extent in the sharper-nose cases. The bluntest nosetip case exhibited unique nonmodal structures which extended into the freestream, and the signature of the second-mode appeared limited to the near-wall region. N factors contours suggested interplay between second-mode content and frequency content outside the second-mode band. Cross-bicoherence calculations indicated that, for the sharper nosetip, nonlinear interactions between the second-mode fundamental and its first harmonic persisted to the point of breakdown. For the blunter nosetip, dominant nonlinear interactions involved low-frequency content.", "date": "2023-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2023-0289", "id_number": "CaltechAUTHORS:20230327-902912000.26", "isbn": "978-1-62410-699-6", "book_title": "AIAA SCITECH 2023 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230327-902912000.26", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2023-0289", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2023-0289", "pub_year": "2023", "author_list": "Paquin, Laura A.; Laurence, Stuart J.; et el." }, { "id": "https://authors.library.caltech.edu/records/at61e-sfc86", "eprint_id": 120476, "eprint_status": "archive", "datestamp": "2023-08-20 08:58:23", "lastmod": "2023-10-23 15:30:55", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hameed-Ahsan", "name": { "family": "Hameed", "given": "Ahsan" }, "orcid": "0000-0001-9563-3959" }, { "id": "Parziale-Nicholaus-J", "name": { "family": "Parziale", "given": "Nick J." }, "orcid": "0000-0001-9880-1727" }, { "id": "Paquin-Laura-A", "name": { "family": "Paquin", "given": "Laura A." }, "orcid": "0000-0002-0218-9666" }, { "id": "Laurence-Stuart-J", "name": { "family": "Laurence", "given": "Stuart J." }, "orcid": "0000-0001-8760-8366" }, { "id": "Yu-Wesley-M", "name": { "family": "Yu", "given": "Wesley M." }, "orcid": "0000-0002-1133-3199" }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "Joanna M." }, "orcid": "0000-0003-3129-5035" } ] }, "title": "Characterization of Transitional, High-Enthalpy Boundary Layers on a Blunted Cone. Part II: FLDI and Higher Order Spectral Analysis", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2023 by Nick Parziale.", "abstract": "FLDI is used to characterize an unstable boundary layer on a 5-degree cone. Results from two experiments are presented: shot 2990 represented a high-enthalpy condition with a 2 mm nosetip and shot 2955 represented a moderate-enthalpy condition with a 5 mm nosetip. For shot 2990, the measured frequency of the second-mode instability using FLDI agreed well with the results obtained using schlieren for an experiment performed at similar conditions, and was in good agreement with the maximum N factor frequency obtained using stability analysis. Cross-bicoherence analysis of the FLDI data revealed several sum and difference interactions which contributed to the generation of the first and second harmonics of the second mode within the boundary layer as well as provided the mechanism of energy exchange between the second mode and the mean flow.", "date": "2023-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2023-0288", "id_number": "CaltechAUTHORS:20230327-902923000.28", "isbn": "978-1-62410-699-6", "book_title": "AIAA SCITECH 2023 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230327-902923000.28", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2023-0288", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2023-0288", "pub_year": "2023", "author_list": "Hameed, Ahsan; Parziale, Nick J.; et el." }, { "id": "https://authors.library.caltech.edu/records/xhc8c-3ed19", "eprint_id": 120473, "eprint_status": "archive", "datestamp": "2023-08-20 08:58:14", "lastmod": "2023-10-23 15:31:07", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Luo-Wen", "name": { "family": "Luo", "given": "Wen" }, "orcid": "0000-0002-7551-5629" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Buckling Analysis of a Ladder Deployable Structure Supporting a Prestressed Film", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2023 by the American Institute of Aeronautics and Astronautics, Inc.", "abstract": "Controlling the deflection and distortion of lightweight space structures is crucial for their function in space. In this paper, we consider the distortion of a ladder structure when being connected to a film using prestressed kirigami springs. The ladder structure is made with longitudinal CFRP Triangular Rollable and Collapsible (TRAC) booms braced by battens in the transverse direction due to prestress. This paper shows that the distortion is the result of the global buckling of the ladder structure. Then, the design space of the ladder structure has been explored to study the effects of design variables on the magnitude of shape distortion.", "date": "2023-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2023-0366", "id_number": "CaltechAUTHORS:20230327-902885000.22", "isbn": "978-1-62410-699-6", "book_title": "AIAA SCITECH 2023 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230327-902885000.22", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2023-0366", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2023-0366", "pub_year": "2023", "author_list": "Luo, Wen and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/avmyq-gq082", "eprint_id": 119091, "eprint_status": "archive", "datestamp": "2023-08-20 08:57:12", "lastmod": "2023-10-23 15:30:20", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ragan-James-F", "name": { "family": "Ragan", "given": "James" } }, { "id": "Rivi\u00e8re-Benjamin", "name": { "family": "Rivi\u00e8re", "given": "Benjamin" }, "orcid": "0000-0003-4189-4090" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Bayesian Active Sensing for Fault Estimation with Belief Space Tree Search", "ispublished": "unpub", "full_text_status": "public", "abstract": "Autonomous spacecraft missions must be robust to system component faults such as sensor and actuator failures. An important setting to study fault tolerance is the Bayesian Active Sensing problem, where the system plans control inputs to gain information and estimate system failures quickly and with high confidence. We model the problem as a belief-state planning problem enabling simultaneous estimation of sensor and actuator failures in the presence of noise. Current belief-state tree search planners provide anytime, approximate solutions, but their underlying particle-filter belief update inhibits performance for information-gathering tasks. To address this issue, we propose POMCPMF, a belief-state tree search that uses an exact belief update in the tree search by exploiting the active sensing problem structure to decouple the belief update as a Kalman filter on the physical state and a particle filter on the failure modes. We validate our method on numerical experiments of spacecraft models with unknown sensor and actuator faults to demonstrate (i) the need for an active and planned sensing solution (as opposed to a passive and greedy solution) and (ii) the superior scalability of our method compared to existing active and planned methods. We then demonstrate the applicability of our algorithm to real systems by extending to a non-linear model and deploying our algorithm on a spacecraft simulator robot.", "date": "2023-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2023-0874", "id_number": "CaltechAUTHORS:20230208-295172000.2", "isbn": "978-1-62410-699-6", "book_title": "AIAA SCITECH 2023 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230208-295172000.2", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2023-0874", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2023-0874", "pub_year": "2023", "author_list": "Ragan, James; Rivi\u00e8re, Benjamin; et el." }, { "id": "https://authors.library.caltech.edu/records/88m4b-3gy40", "eprint_id": 120472, "eprint_status": "archive", "datestamp": "2023-08-20 08:58:11", "lastmod": "2023-10-23 15:31:04", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Oshima-Emile-K", "name": { "family": "Oshima", "given": "Emile" }, "orcid": "0000-0002-1689-3726" }, { "id": "Lee-Nicole-H", "name": { "family": "Lee", "given": "Nicole" } }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "Morteza" }, "orcid": "0000-0003-0754-4193" }, { "id": "Lee-Vincent-S-H", "name": { "family": "Lee", "given": "Vincent" } }, { "id": "Khodadoust-Abdollah", "name": { "family": "Khodadoust", "given": "Abdollah" } } ] }, "title": "Development of a physics-informed neural network to enhance wind tunnel data for aerospace design", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2023 by Emile Oshima, Nicole Lee, Morteza Gharib, Vincent Lee, and Abdollah Khodadoust.", "abstract": "In recent years, physics-informed neural networks (PINNs) have emerged as a novel approach to solving PDEs in many applications, including the Navier-Stokes equations in fluid mechanics. We seek to develop a tool based on PINNs that can bridge gaps in the experimental and computational methods currently utilized in aerospace design and analysis. The feasibility of such a product is demonstrated in the context of 2D steady flows over airfoil geometries. Reconstruction of full flow fields from spatially sparse measurements of pressure and flow direction is presented, motivated by prevalent practices in subsonic wind tunnel testing campaigns. Areas of algorithm improvement, directions for future research, and broader visions for the collaboration are discussed.", "date": "2023-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2023-0540", "id_number": "CaltechAUTHORS:20230327-902874000.20", "isbn": "978-1-62410-699-6", "book_title": "AIAA SCITECH 2023 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230327-902874000.20", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2023-0540", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2023-0540", "pub_year": "2023", "author_list": "Oshima, Emile; Lee, Nicole; et el." }, { "id": "https://authors.library.caltech.edu/records/vr2z7-3xq53", "eprint_id": 116240, "eprint_status": "archive", "datestamp": "2023-08-20 07:13:23", "lastmod": "2023-10-23 15:19:07", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Delaune-Jeff", "name": { "family": "Delaune", "given": "Jeff" } }, { "id": "Izraelevitz-Jacob-S", "name": { "family": "Izraelevitz", "given": "Jacob" } }, { "id": "Sirlin-Samuel", "name": { "family": "Sirlin", "given": "Samuel" } }, { "id": "Sternberg-David", "name": { "family": "Sternberg", "given": "David" } }, { "id": "Giersch-Louis", "name": { "family": "Giersch", "given": "Louis" } }, { "id": "Tosi-L-Phillipe", "name": { "family": "Tosi", "given": "L. Phillipe" } }, { "id": "Skliyanskiy-Evgeniy", "name": { "family": "Skliyanskiy", "given": "Evgeniy" } }, { "id": "Young-Larry", "name": { "family": "Young", "given": "Larry" } }, { "id": "Mischna-Michael-A", "name": { "family": "Mischna", "given": "Michael" }, "orcid": "0000-0002-8022-5319" }, { "id": "Withrow-Maser-Shannah", "name": { "family": "Withrow-Maser", "given": "Shannah" } }, { "id": "Mueller-Juergen", "name": { "family": "Mueller", "given": "Juergen" } }, { "id": "Bowman-Joshua", "name": { "family": "Bowman", "given": "Joshua" } }, { "id": "Wallace-Mark-S", "name": { "family": "Wallace", "given": "Mark S." } }, { "id": "Grip-H\u00e5vard-V", "name": { "family": "Grip", "given": "H\u00e5vard F." } }, { "id": "Matthies-Larry-H", "name": { "family": "Matthies", "given": "Larry" } }, { "id": "Johnson-Wayne", "name": { "family": "Johnson", "given": "Wayne" } }, { "id": "Keennon-Matthew", "name": { "family": "Keennon", "given": "Matthew" } }, { "id": "Pipenberg-Benjamin", "name": { "family": "Pipenberg", "given": "Benjamin" } }, { "id": "Patek-Harsh", "name": { "family": "Patel", "given": "Harsh" } }, { "id": "Lim-Christopher-Y", "name": { "family": "Lim", "given": "Christopher" } }, { "id": "Schutte-Aaron", "name": { "family": "Schutte", "given": "Aaron" } }, { "id": "Veismann-Marcel", "name": { "family": "Veismann", "given": "Marcel" }, "orcid": "0000-0001-8106-6738" }, { "id": "Cummings-Haley", "name": { "family": "Cummings", "given": "Haley" } }, { "id": "Conley-Sarah", "name": { "family": "Conley", "given": "Sarah" } }, { "id": "Bapst-Jonathan", "name": { "family": "Bapst", "given": "Jonathan" } }, { "id": "Tzanetos-Theodore", "name": { "family": "Tzanetos", "given": "Theodore" } }, { "id": "Brockers-Roland", "name": { "family": "Brockers", "given": "Roland" } }, { "id": "Jain-Abhinandan", "name": { "family": "Jain", "given": "Abhinandan" } }, { "id": "Bayard-David-S", "name": { "family": "Bayard", "given": "David" } }, { "id": "Chmielewski-Art", "name": { "family": "Chmielewski", "given": "Art" } }, { "id": "Toupet-Olivier", "name": { "family": "Toupet", "given": "Olivier" } }, { "id": "Burdick-J-W", "name": { "family": "Burdick", "given": "Joel" }, "orcid": "0000-0002-3091-540X" }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "Morteza" }, "orcid": "0000-0003-0754-4193" }, { "id": "Balaram-J-Bob", "name": { "family": "Balaram", "given": "J." } } ] }, "title": "Mid-Air Helicopter Delivery at Mars Using a Jetpack", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2022 IEEE. \n\nThe authors would like to thank the technical reviewers who provided valuable feedback at different stages of the design: Jeffery Hall, Miguel San Martin, Joe Melko, Kim Aaron, Erik Bailey, Chris Porter, Kim Aaron, Mike Paul Hughes, Art Casillas, Carl Guernsey, Kalind Carpenter, Matthew Heverly, Joshua Ravich and Ian Clark. \n\nPart of the research described in this paper was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004).", "abstract": "Mid-Air Helicopter Delivery (MAHD) is a new Entry, Descent and Landing (EDL) architecture to enable in situ mobility for Mars science at lower cost than previous missions. It uses a jetpack to slow down a Mars Science Helicopter (MSH) after separation from the backshell, and reach aerodynamic conditions suitable for helicopter take-off in mid air. For given aeroshell dimensions, only MAHD's lander-free approach leaves enough room in the aeroshell to accommodate the largest rotor option for MSH. This drastically improves flight performance, notably allowing +150% increased science payload mass. Compared to heritage EDL approaches, the simpler MAHD architecture is also likely to reduce cost, and enables access to more hazardous and higher-elevation terrains on Mars. This paper introduces a design for the MAHD system architecture and operations. We present a mechanical configuration that fits both MSH and the jetpack within the 2.65-m Mars heritage aeroshell, and a jetpack control architecture which fully leverages the available helicopter avionics. We discuss preliminary numerical models of the flow dynamics resulting from the interaction between the jets, the rotors and the side winds. We define a force-torque sensing architecture capable of handling the wind and trimming the rotors to prepare for safe take-off. Finally, we analyze the dynamic environment and closed-loop control simulation results to demonstrate the preliminary feasibility of MAHD.", "date": "2022-03-05", "date_type": "published", "publisher": "IEEE", "id_number": "CaltechAUTHORS:20220811-935426000", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220811-935426000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech", "grant_number": "80NM0018D0004" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/aero53065.2022.9843825", "pub_year": "2022", "author_list": "Delaune, Jeff; Izraelevitz, Jacob; et el." }, { "id": "https://authors.library.caltech.edu/records/1g048-8er75", "eprint_id": 113383, "eprint_status": "archive", "datestamp": "2023-08-20 06:28:17", "lastmod": "2023-10-23 15:34:46", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hameed-Ahsan", "name": { "family": "Hameed", "given": "Ahsan" } }, { "id": "Shekhtman-David", "name": { "family": "Shekhtman", "given": "David" }, "orcid": "0000-0003-0648-5435" }, { "id": "Parziale-Nicholaus-J", "name": { "family": "Parziale", "given": "Nick" }, "orcid": "0000-0001-9880-1727" }, { "id": "Paquin-Laura-A", "name": { "family": "Paquin", "given": "Laura A." } }, { "id": "Skinner-Shaun", "name": { "family": "Skinner", "given": "Shaun" }, "orcid": "0000-0003-3650-983X" }, { "id": "Laurence-Stuart-J", "name": { "family": "Laurence", "given": "Stuart J." }, "orcid": "0000-0001-8760-8366" }, { "id": "Yu-Wesley-M", "name": { "family": "Yu", "given": "Wesley M." }, "orcid": "0000-0002-1133-3199" }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "Joanna M." }, "orcid": "0000-0003-3129-5035" } ] }, "title": "Hypersonic Boundary-Layer Instability on a Highly Cooled Cone. Part I: Q-FLDI Measurement and Instability Calculations", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2022 by Nick Parziale. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.", "abstract": "In this paper, a Q-FLDI system was constructed to correlate disturbances inside and outside of the boundary layer over a blunted cone in high-enthalpy, hypersonic flow at T5, the free- piston-driven reflected-shock tunnel at California Institute of Technology. We present results for three shots representing a fully-turbulent case with a 5 mm nose-tip radius, an unstable case with a 5 mm nose-tip radius at moderate enthalpy (6 MJ/kg), and an unstable case with a 2 mm nose-tip radius at higher enthalpy (10.5 MJ/kg). In the fully-turbulent case, the spectra indicate the possibility of a region where there is a power-law variation in the spectrum. For the unstable case with a 2 mm nose-tip radius at higher enthalpy (10.5 MJ/kg), the FLDI detected the second mode instability at approximately 1 MHz. This agrees well with results obtained using the schlieren technique for experiments performed in this campaign at similar conditions. The mismatch when compared to stability calculations for this case could be attributed to run-condition calculation error. An unstable case with a 5 mm nose-tip radius at moderate enthalpy (6 MJ/kg) is also presented. In this case, there is more content measured outside of the boundary layer than inside. For this case, computations of the mean flow show that the entropy-layer had not been swallowed at the point of measurement suggesting the elevated energy content outside the boundary layer could be due to entropy layer instabilities or oblique waves not considered in the stability analysis.", "date": "2022-01-03", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "id_number": "CaltechAUTHORS:20220210-928356000", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220210-928356000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2022-0734", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2022-0734", "pub_year": "2022", "author_list": "Hameed, Ahsan; Shekhtman, David; et el." }, { "id": "https://authors.library.caltech.edu/records/y0yab-v0024", "eprint_id": 113395, "eprint_status": "archive", "datestamp": "2023-08-20 06:28:57", "lastmod": "2023-10-23 15:35:26", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Arya-Manan", "name": { "family": "Arya", "given": "Manan" } }, { "id": "Hodges-Richard", "name": { "family": "Hodges", "given": "Richard" } }, { "id": "Sauder-Jonathan-F", "name": { "family": "Sauder", "given": "Jonathan F." } }, { "id": "Horst-Stephen", "name": { "family": "Horst", "given": "Stephen" } }, { "id": "Mobrem-Mehran", "name": { "family": "Mobrem", "given": "Mehran" } }, { "id": "Pedivellano-Antonio", "name": { "family": "Pedivellano", "given": "Antonio" }, "orcid": "0000-0003-2321-7301" }, { "id": "Wen-Alexander", "name": { "family": "Wen", "given": "Alexander" } }, { "id": "Truong-Alan", "name": { "family": "Truong", "given": "Alan" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Lightweight Composite Reflectarray that can be Flattened, Folded, and Coiled for Compact Stowage", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2022 by the American Institute of Aeronautics and Astronautics, Inc. The U.S. Government has a royalty-free license to exercise all rights under the copyright claimed herein for Governmental purposes. All other rights are reserved by the copyright owner.", "abstract": "Herein is presented a design for a lightweight 5 m x 1 m radio-frequency (RF) reflector that can be flattened, folded, and coiled for compact stowage on board an ESPA-class spacecraft. The reflector is a reflectarray that operates at 3.2 GHz. Compared to state-of-the-art technologies for RF reflectors, the presented design has advantages in terms of areal density, stiffness, deployed stability, and scalability. Thermal and structural analysis is presented to demonstrate deployed stiffness and thermoelastic stability of the proposed design. Thermal analysis is used to predict in-space deployed temperatures in an operational condition, and structural finite element analysis is used to predict deployed vibration modes and frequencies, and the thermoelastic deformation of the deployed reflector. Also presented are the fabrication, assembly, and testing of two one-third-scale-length full-scale-width 1.7 m x 1 m test articles. These test articles are used to experimentally demonstrate RF functioning, stowage, deployment, and RF performance after deployment.", "date": "2022-01-03", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2022-1886", "id_number": "CaltechAUTHORS:20220210-928455000", "isbn": "978-1-62410-631-6", "book_title": "AIAA SCITECH 2022 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220210-928455000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2022-1886", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2022-1886", "pub_year": "2022", "author_list": "Arya, Manan; Hodges, Richard; et el." }, { "id": "https://authors.library.caltech.edu/records/2c5rw-jn198", "eprint_id": 113397, "eprint_status": "archive", "datestamp": "2023-08-20 06:29:05", "lastmod": "2023-10-23 15:35:20", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Neamati-Daniel", "name": { "family": "Neamati", "given": "Daniel" }, "orcid": "0000-0002-1555-1433" }, { "id": "Nakka-Yashwanth-Kumar-K", "name": { "family": "Nakka", "given": "Yashwanth Kumar K." }, "orcid": "0000-0001-7897-3644" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Learning-based methods to model small body gravity fields for proximity operations: Safety and Robustness", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2022 American Institute of Aeronautics and Astronautics.\n\nAccepted Version - 2112.09998.pdf
", "abstract": "Accurate gravity field models are essential for safe proximity operations around small bodies. State-of-the-art techniques use spherical harmonics or high-fidelity polyhedron shape models. Unfortunately, these techniques can become inaccurate near the surface of the small body or have high computational costs, especially for binary or heterogeneous small bodies. New learning-based techniques do not encode a predefined structure and are more versatile. In exchange for versatility, learning-based techniques can be less robust outside the training data domain. In deployment, the spacecraft trajectory is the primary source of dynamics data. Therefore, the training data domain should include spacecraft trajectories to accurately evaluate the learned model's safety and robustness. We have developed a novel method for learning-based gravity models that directly uses the spacecraft's past trajectories. We further introduce a method to evaluate the safety and robustness of learning-based techniques via comparing accuracy within and outside of the training domain. We demonstrate this safety and robustness method for two learning-based frameworks: Gaussian processes and neural networks. Along with the detailed analysis provided, we empirically establish the need for robustness verification of learned gravity models when used for proximity operations.", "date": "2022-01-03", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2022-2271", "id_number": "CaltechAUTHORS:20220210-928467000", "isbn": "978-1-62410-631-6", "book_title": "AIAA SCITECH 2022 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220210-928467000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2022-2271", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2022-2271", "primary_object": { "basename": "2112.09998.pdf", "url": "https://authors.library.caltech.edu/records/2c5rw-jn198/files/2112.09998.pdf" }, "pub_year": "2022", "author_list": "Neamati, Daniel; Nakka, Yashwanth Kumar K.; et el." }, { "id": "https://authors.library.caltech.edu/records/0fknb-fc114", "eprint_id": 113394, "eprint_status": "archive", "datestamp": "2023-08-20 06:28:53", "lastmod": "2023-10-23 15:35:04", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Wen-Alexander", "name": { "family": "Wen", "given": "Alexander" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Launch Vibration of Pre-Tensioned Coiled Structures", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2022 by the American Institute of Aeronautics and Astronautics, Inc.", "abstract": "Relative movement between slipping layers in a coil due to vibration can cause defects in the structure or damage functional elements, such as photovoltaic cells, attached to the structure. Radial contact pressure between successive layers due to coiling pre-tension provides a frictional force that can be used to resist inter-layer slip. In this study, we propose a stress-field based, analytical friction model to use as a criterion for estimating the frictional shear capacity of a wound roll prior to the onset of slip. Because the radial pressure varies with radial position in the coil, the shear capacity against slippage also varies with position. This analytical shear capacity can then be compared against the shear resultants obtained in finite-element simulations of coiled structures undergoing vibration load. Rather than modeling discrete windings of wound rolls, the starting coiled-stiff assumption is the coil is tensioned sufficiently to behave as a solid. Thus, a finite-element vibration study of a homogenized solid is used to find the loads and locations where shear resultant is larger than the estimated shear capacity, indicating slip. The validity of the coiled-stiff assumption is experimentally verified using a vibration experiment that measures the variation in apparent stiffness of a coiled membrane wound under varying tensions.", "date": "2022-01-03", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2022-1883", "id_number": "CaltechAUTHORS:20220210-928446000", "isbn": "978-1-62410-631-6", "book_title": "AIAA SCITECH 2022 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220210-928446000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2022-1883", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2022-1883", "pub_year": "2022", "author_list": "Wen, Alexander and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/7bfgm-vta12", "eprint_id": 113399, "eprint_status": "archive", "datestamp": "2023-08-20 06:29:13", "lastmod": "2023-10-23 15:35:29", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Tisdale-Malcolm", "name": { "family": "Tisdale", "given": "Malcom" } }, { "id": "Dul\u00e1-Isabella", "name": { "family": "Dul\u00e1", "given": "Isabella" } }, { "id": "Pabon-Madrid-Luis", "name": { "family": "Pabon Madrid", "given": "Luis" } }, { "id": "Verkhovodova-Polina", "name": { "family": "Verkhovodova", "given": "Polina" } }, { "id": "P\u00e9not-Jules", "name": { "family": "P\u00e9not", "given": "Jules" } }, { "id": "Coimbra-Kaila", "name": { "family": "Coimbra", "given": "Kaila" } }, { "id": "Soldner-Leah", "name": { "family": "Soldner", "given": "Leah" } }, { "id": "Gupta-Tanmay", "name": { "family": "Gupta", "given": "Tanmay" } }, { "id": "Musuku-Rithvik", "name": { "family": "Musuku", "given": "Rithvik" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Design of a Modular and Orientable Electrodynamic Shield for Lunar Dust Mitigation", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2022 by the American Institute of Aeronautics and Astronautics, Inc. \n\nThe authors would like to acknowledge the Breakthrough, Initiative, and Game-changing (BIG) Idea Challenge, the Space Grant Project, NASA, and the National Institute of Aerospace for sponsoring this research project. The authors would like to Dr. Soon-Jo Chung for his excellent advisership, guidance, and support. The authors would finally like to acknowledge Dr. Jason Kastner, Dr. Manan Arya, Dr. Charles Elachi, and Dr. Robert Behnken for support and constructive suggestions.\n\nAccepted Version - Design_of_a_Modular_and_Orientable_Electrodynamic_Shield_for_Lunar_Dust_Mitigation-3.pdf
", "abstract": "Lunar dust is considered one of the main limiting factors for lunar missions of extended duration and the establishment of a sustainable human presence on the moon. The dust is difficult to shield against and remove as it is extremely abrasive, highly cohesive, small, and may be electrostatically charged. In addition to threatening astronaut health, lunar dust issues have also resulted in incorrect instrument readings, vision and optical system obscuration, performance reduction, altered thermal properties, and equipment failure. To address these issues, this paper introduces the Habitat Orientable and Modular Electrodynamic Shield (HOMES). HOMES is a collection of 0.25 m x 0.25 m and 1.1 kg panels requiring 8 watts of power, embedded with Electrodynamic Dust Shielding (EDS) to mitigate lunar dust in a variety of applications. The modular design of HOMES addresses the gap in scalability of current EDS implementations. The EDS within HOMES is a series of 3-phase wire electrodes that induce a traveling wave-like electric field to locomote dust particles in a fixed direction. The fringing electric field generated by the EDS can keep dust particles off spacesuits and nearby objects. HOMES is a scalable modular system with rotationally symmetric panels that can be tiled to fit the desired use case. The panels are orientable to allow for customizable field directions. Among other applications, HOMES can be used to create dust free and self-cleaning work surfaces, floors, and doormats. This technology advances the state-of-the-art by incorporating EDS in a lightweight, modular design that will allow for flexibility in lunar dust mitigation within the context of the Artemis missions and beyond. The paper is divided into the following sections: problem statement and background, where the lunar dust problem and the current state of EDS technology are introduced; project description, where project requirements and design assumptions are detailed; mechanical design, outlining the EDS enclosure capable of sustaining the extreme lunar environment and an astronaut's weight; electrical design, detailing the layout of electrodes and EDS electronics; verification and validation, plan to bring homes to Technological Readiness Level 6; path to flight, discussing the necessary steps to ready HOMES for the moon. Having been awarded funding through NASA's BIG Idea Challenge, future work will focus on the construction, testing, and experimental results of this novel technology.", "date": "2022-01-03", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2022-2623", "id_number": "CaltechAUTHORS:20220210-928477000", "isbn": "978-1-62410-631-6", "book_title": "AIAA SCITECH 2022 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220210-928477000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA 2022 Breakthrough, Innovative and Game-changing (BIG) Idea Challenge" }, { "agency": "National Space Grant College and Fellowship Project" }, { "agency": "National Institute of Aerospace (NIA)" } ] }, "other_numbering_system": { "items": [ { "id": "2022-2623", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2022-2623", "primary_object": { "basename": "Design_of_a_Modular_and_Orientable_Electrodynamic_Shield_for_Lunar_Dust_Mitigation-3.pdf", "url": "https://authors.library.caltech.edu/records/7bfgm-vta12/files/Design_of_a_Modular_and_Orientable_Electrodynamic_Shield_for_Lunar_Dust_Mitigation-3.pdf" }, "pub_year": "2022", "author_list": "Tisdale, Malcom; Dul\u00e1, Isabella; et el." }, { "id": "https://authors.library.caltech.edu/records/m2s5b-nng16", "eprint_id": 113392, "eprint_status": "archive", "datestamp": "2023-08-20 06:28:47", "lastmod": "2023-10-23 15:35:07", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Finch-Peter-M", "name": { "family": "Finch", "given": "Peter M." } }, { "id": "Schwartz-Tal", "name": { "family": "Schwartz", "given": "Tal" }, "orcid": "0000-0002-5022-450X" }, { "id": "Girard-Julian-J", "name": { "family": "Girard", "given": "Julian" }, "orcid": "0000-0002-8101-015X" }, { "id": "Yu-Wesley-M", "name": { "family": "Yu", "given": "Wesley M." }, "orcid": "0000-0002-1133-3199" }, { "id": "Strand-Christopher-L", "name": { "family": "Strand", "given": "Christopher" }, "orcid": "0000-0002-4112-6668" }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "Joanna M." }, "orcid": "0000-0003-3129-5035" }, { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "Hans G." }, "orcid": "0000-0002-4903-8419" }, { "id": "Hanson-Ronald-K", "name": { "family": "Hanson", "given": "Ronald K." }, "orcid": "0000-0002-8030-5327" } ] }, "title": "Near-Body Measurements in Hypersonic Cylinder Flows in the T5 Reflected Shock Tunnel by Tunable Diode Laser Absorption Spectroscopy", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2022 by Peter M. Finch. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.", "abstract": "We report on near-body measurements of nitric oxide (NO) rotational and vibrational temperatures and concentration in the hypersonic flow around a cylindrical test model in the Caltech T5 reflected shock tunnel. An array of quantum cascade lasers (QCLs) and distributed feedback lasers (DFBs) emitted infrared light in the vicinity of 5 microns resonant with several quantum transitions of NO. Tunable diode laser absorption spectroscopy (TDLAS) was employed to infer path-averaged flow parameters of temperature and NO concentration, both in front of and behind the bow shock around the cylinder, at a measurement rate of 50 kHz. The fractions of laser beam paths behind the shock at different spatial locations were also discerned, thus providing a measurement of the shock location. Two shots at the same nominal flow condition with stagnation enthalpy ~ 8 MJ/kg, freestream temperature ~ 1050 K, and freestream velocity ~ 3600 m/s were explored. Laser beams were pitched at three locations at radial distances of 9 mm, 19.5 mm, and 30 mm from the cylinder surface along a plane 120 degrees relative to the upstream direction. The cylinder was 1.75 inches in diameter with an aspect ratio of 3. Beam locations were specified relative to the cylinder using a custom-made alignment grid that could be rigidly attached to the cylinder end-span during the alignment step. To isolate measurements of the freestream and near-cylinder flow structure, optical arms with flow-cutting wedges were designed to divert the boundary-layer and shear-layer of the nozzle exit flow away from the field of view and deliver the laser beams directly into the core of the flow. Freestream measurements from this dataset show general agreement with those in previous works. Nevertheless, shot-to-shot variations are sufficient to confound the interpretation of the post-shock gas characteristics, which rely on the freestream conditions. A novel technique to extract freestream information from the TDLAS path-average is presented, permitting the independent measurement of the freestream each shot without reliance on previous characterization.", "date": "2022-01-03", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2022-1705", "id_number": "CaltechAUTHORS:20220210-928432000", "isbn": "978-1-62410-631-6", "book_title": "AIAA Scitech 2022 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220210-928432000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2022-1705", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2022-1705", "pub_year": "2022", "author_list": "Finch, Peter M.; Schwartz, Tal; et el." }, { "id": "https://authors.library.caltech.edu/records/16t16-nm594", "eprint_id": 113385, "eprint_status": "archive", "datestamp": "2023-08-20 06:28:24", "lastmod": "2023-10-23 15:34:40", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Garcia-Mayoral-Ricardo", "name": { "family": "Garcia-Mayoral", "given": "Ricardo" } }, { "id": "Durbin-Paul-A", "name": { "family": "Durbin", "given": "Paul" } }, { "id": "McKeon-B-J", "name": { "family": "McKeon", "given": "Beverley J." }, "orcid": "0000-0003-4220-1583" }, { "id": "Piomelli-Ugo", "name": { "family": "Piomelli", "given": "Ugo" } }, { "id": "Sandberg-Richard-D", "name": { "family": "Sandberg", "given": "Richard D." } }, { "id": "Chung-Daniel", "name": { "family": "Chung", "given": "Daniel" }, "orcid": "0000-0003-3732-364X" }, { "id": "Hutchins-Nicholas", "name": { "family": "Hutchins", "given": "Nicholas" }, "orcid": "0000-0003-1599-002X" }, { "id": "Bensow-Rickard", "name": { "family": "Bensow", "given": "Rickard" } }, { "id": "Knopp-Tobias-A", "name": { "family": "Knopp", "given": "Tobias A." } }, { "id": "Krumbein-Andreas", "name": { "family": "Krumbein", "given": "Andreas" } }, { "id": "Roy-Christopher-J", "name": { "family": "Roy", "given": "Christopher J." } }, { "id": "Gargiulo-Arlo", "name": { "family": "Gargiulo", "given": "Aldo" } }, { "id": "Lowe-K-T", "name": { "family": "Lowe", "given": "K. T." } }, { "id": "Toxopeus-Serge-L", "name": { "family": "Toxopeus", "given": "Serge L." } } ] }, "title": "Modeling of high-Re, incompressible, non-equilibrium, rough-wall boundary layers for naval applications under NATO-AVT349", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2022 by Ricardo Garcia-Mayoral, Paul Durbin, Beverley McKeon, Ugo Piomelli, Richard D. Sandberg , Daniel Chung, Nicholas Hutchins, Rickard E. Bensow, Tobias Knopp, Andreas Krumbein, Christopher J. Roy, Aldo Gargiulo, K. Todd Lowe and Serge Toxopeus. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.", "abstract": "This paper discusses the modeling activity of the NATO-STO Research Task Group AVT-349. The aim of this group is to improve the understanding and modeling of boundary layers in the complex flow around water vehicles. As such, the focus is on incompressible, high-Reynolds-number flows that can be subject to non-equilibrium conditions such as strong pressure gradients, three-dimensionality, and surface roughness and heterogeneity. The Task Group has identified a reduced number of simpler problems in which the above conditions can be studied separately and in controlled environments. These include two-dimensional rough-wall boundary layers under both zero and non-zero pressure gradients, two-dimensional smooth-wall boundary layers subject to pressure gradients, and boundary layers around smooth bodies of revolution and three-dimensional obstacles. An experimental and computational data set is being assembled for further analysis and insight into the flow mechanisms involved, as well as the shortcomings of state-of-the-art models. This paper gives an outlook of the modeling effort within the Task Group, as well its different objectives. These include predicting the effect of roughness in equilibrium conditions; assessing the applicability and/or extension of equilibrium models and predictions to non-equilibrium conditions, in particular when outer-layer similarity is lost; the development of near-wall models based on a reduced-order resolvent framework; and the use of machine-aided methods in closure models.", "date": "2022-01-03", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2022-1033", "id_number": "CaltechAUTHORS:20220210-928380000", "isbn": "978-1-62410-631-6", "book_title": "AIAA SCITECH 2022 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220210-928380000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2022-1033", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2022-1033", "pub_year": "2022", "author_list": "Garcia-Mayoral, Ricardo; Durbin, Paul; et el." }, { "id": "https://authors.library.caltech.edu/records/hm8ec-spv58", "eprint_id": 113391, "eprint_status": "archive", "datestamp": "2023-08-20 06:28:43", "lastmod": "2023-10-23 15:35:14", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Yu-Wesley-M", "name": { "family": "Yu", "given": "Wesley M." }, "orcid": "0000-0002-1133-3199" }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "Joanna M." }, "orcid": "0000-0003-3129-5035" }, { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "Hans G." }, "orcid": "0000-0002-4903-8419" } ] }, "title": "Freestream Static Pressure Measurements in the T5 Reflected Shock Tunnel", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2022 by the American Institute of Aeronautics and Astronautics, Inc.", "abstract": "In hypervelocity reflected shock tunnels, accurate static pressure measurements are key to interpretation of spectroscopic measurements characterizing the freestream thermodynamic state, as well as in determining the arrival of driver gas in the test section. However, measurements are challenging due to the significant mechanical and aerodynamic loads that are present in such impulse facilities. A static pressure probe was built for use in the T5 Free Piston Shock Tunnel at the California Institute of Technology based on the design of Behrens. Test conditions covered stagnation enthalpy from 8 to 16MJ/kg and freestream pressure from 7 to 27 kPa. With proper protection using silicone gel and tubing, repeatable static pressure measurements with good signal quality and within 2.5% uncertainty were obtained. Nozzle startup processes and driver gas arrival are also evident in the pressure traces. A smaller version of the static pressure probe, more easily accommodated together with models for freestream measurements, was also tested to provide a measure of repeatability and shot-to-shot variation, together with a new companion pitot probe. Static pressure instrument responses are in good agreement with theoretical models and Navier-Stokes simulations.", "date": "2022-01-03", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "id_number": "CaltechAUTHORS:20220210-928423000", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220210-928423000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2022-1658", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2022-1658", "pub_year": "2022", "author_list": "Yu, Wesley M.; Austin, Joanna M.; et el." }, { "id": "https://authors.library.caltech.edu/records/3n3az-5fa66", "eprint_id": 113386, "eprint_status": "archive", "datestamp": "2023-08-20 06:28:27", "lastmod": "2023-10-23 15:34:37", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Gdoutos-Eleftherios-E", "name": { "family": "Gdoutos", "given": "Eleftherios" } }, { "id": "Sommer-Charles-F", "name": { "family": "Sommer", "given": "Charles F." } }, { "id": "Truong-Alan", "name": { "family": "Truong", "given": "Alan" } }, { "id": "Wen-Alexander", "name": { "family": "Wen", "given": "Alexander" } }, { "id": "Pedivellano-Antonio", "name": { "family": "Pedivellano", "given": "Antonio" }, "orcid": "0000-0003-2321-7301" }, { "id": "Ubamanyu-Kanthasamy", "name": { "family": "Ubamanyu", "given": "Kanthasamy" } }, { "id": "Madonna-Richard-G", "name": { "family": "Madonna", "given": "Richard G." }, "orcid": "0000-0002-8191-4896" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Development of the Deployable on-Orbit ultraLight Composite Experiment (DOLCE) for the Space Solar Power Project Demonstration Mission", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2022 by Eleftherios Gdoutos, Charles Sommer, Alan Truong, Alexander Wen, Antonio Pedivellano, Uba Ubamanyu, Rich Madonna, Sergio Pellegrino. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.", "abstract": "We describe the development of an engineering model of the DOLCE payload which will demonstrate on orbit for the first time the deployment of an ultralight Caltech SSPP structure. Deployment tests at the subsystem and system levels, launch load analysis and testing, and accelerated aging tests have been conducted. The DOLCE payload will be launched with the SSPD-1 mission which will demonstrate space-based solar power key enabling technologies in photovoltaics, power beaming, and deployable structures.", "date": "2022-01-03", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2022-1266", "id_number": "CaltechAUTHORS:20220210-928385000", "isbn": "978-1-62410-631-6", "book_title": "AIAA SCITECH 2022 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220210-928385000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2022-1266", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Space-Solar-Power-Project" } ] }, "doi": "10.2514/6.2022-1266", "pub_year": "2022", "author_list": "Gdoutos, Eleftherios; Sommer, Charles F.; et el." }, { "id": "https://authors.library.caltech.edu/records/h846m-vrm42", "eprint_id": 113380, "eprint_status": "archive", "datestamp": "2023-08-20 06:28:08", "lastmod": "2023-10-23 15:34:24", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Luo-Wen", "name": { "family": "Luo", "given": "Wen" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Propagating Instabilities in Coilable Booms", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2022 by the American Institute of Aeronautics and Astronautics, Inc.", "abstract": "Coilable booms consisting of thin composite shells bonded along a common edge are being considered for novel deployable spacecraft structures. These booms have many desirable features such as light weight, high stiffness, and high packaging efficiency, but this successful realization poses new challenges. In this paper, we study the propagating buckles that have been observed in the transition region between the coiled and deployed parts of the booms. These buckles, which can cause local stress concentrations and material failure, are typical of booms with built-up sections. They do not occur in tape springs. We investigate the root cause for the propagating buckles and discuss the possibility of limiting the buckle growth by increasing the material shear modulus.", "date": "2022-01-03", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2022-0407", "id_number": "CaltechAUTHORS:20220210-928328000", "isbn": "978-1-62410-631-6", "book_title": "AIAA SCITECH 2022 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220210-928328000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2022-0407", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2022-0407", "pub_year": "2022", "author_list": "Luo, Wen and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/6vf0h-xac18", "eprint_id": 113390, "eprint_status": "archive", "datestamp": "2023-08-20 06:28:40", "lastmod": "2023-10-23 15:34:57", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Allen-Brayden", "name": { "family": "Aller", "given": "Brayden" }, "orcid": "0000-0002-5258-4154" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" }, { "id": "Kinkaid-Nathan", "name": { "family": "Kinkaid", "given": "Nathan" } }, { "id": "Mejia-Ariza-Juan", "name": { "family": "Mejia-Ariza", "given": "Juan" } }, { "id": "Chan-Patrick", "name": { "family": "Chan", "given": "Patrick" } }, { "id": "Pena-Francisco", "name": { "family": "Pena", "given": "Francisco" } } ] }, "title": "Health Monitoring of High Strain Composites Using Embedded Fiber Bragg Grating Sensors", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2022 by Brayden Aller, Sergio Pellegrino, Nathan Kinkaid, Juan Mejia-Ariza, Richard Otis, Patrick Hon Man Chan and Francisco Pena. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.", "abstract": "A study on the use of fiber Bragg grating sensors to measure strains in thin-walled composite structures is presented. It includes measurement of the gage factor, or strain conversion coefficient, of small diameter fiber optic sensors. Fiber Bragg grating sensor arrays were embedded into high strain composites and the buildup of strains during manufacturing was tracked. \u03bcCT scans of these composites were taken after curing to analyze the micro-structure in the regions surrounding the embedded sensors. Composite laminates with embedded sensors were subjected to a controlled coiling experiment to evaluate the accuracy of the sensors in measuring internal strains.", "date": "2022-01-03", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2022-1622", "id_number": "CaltechAUTHORS:20220210-928413000", "isbn": "978-1-62410-631-6", "book_title": "AIAA SCITECH 2022 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220210-928413000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2022-1622", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2022-1622", "pub_year": "2022", "author_list": "Aller, Brayden; Pellegrino, Sergio; et el." }, { "id": "https://authors.library.caltech.edu/records/q0ve0-jk780", "eprint_id": 113393, "eprint_status": "archive", "datestamp": "2023-08-20 06:28:50", "lastmod": "2023-10-23 15:35:10", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Leibowitz-Matthew-G", "name": { "family": "Leibowitz", "given": "Matthew G." }, "orcid": "0000-0002-7297-2592" }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "Joanna M." }, "orcid": "0000-0003-3129-5035" } ] }, "title": "Mid-Wave Infrared Radiation Experiments in Hypervelocity CO\u2082 Blunt Body Flow", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2022 by California Institute of Technology. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.", "abstract": "Forebody and wake MWIR spectral radiance and shock shape measurements are obtained in the T5 Reflected Shock Tunnel in CO\u2082 flow over a 25.3:1 scaled Mars Science Laboratory (MSL) heat shield model (177.8 mm base diameter). Two conditions are developed to match the binary scaling parameter and total enthalpy at selected points on flight trajectories of the recent MSL and ExoMars missions at enthalpies of 6.1 MJ/kg and 7.7 MJ/kg, respectively. The model is mounted at a 0 degree AOA to emulate the ExoMars mission ballistic entry trajectory while the model is mounted at a 16 degree AOA for the MSL mission lifting entry trajectory. The ExoMars shock layer can be considered optically thin while boundary layer absorption occurs for the MSL forebody shock layer measurements. This work builds on our previous studies of mid-wave infrared radiation measurements in high-enthalpy ground test facilities.", "date": "2022-01-03", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2022-1783", "id_number": "CaltechAUTHORS:20220210-928437000", "isbn": "978-1-62410-631-6", "book_title": "AIAA SCITECH 2022 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220210-928437000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2022-1783", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2022-1783", "pub_year": "2022", "author_list": "Leibowitz, Matthew G. and Austin, Joanna M." }, { "id": "https://authors.library.caltech.edu/records/xx90b-pm914", "eprint_id": 113398, "eprint_status": "archive", "datestamp": "2023-08-20 06:29:08", "lastmod": "2023-10-23 15:35:23", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Oshima-Emile", "name": { "family": "Oshima", "given": "Emile" } }, { "id": "Wygnanski-Israel-J", "name": { "family": "Wygnanski", "given": "Israel J." } }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "Morteza" }, "orcid": "0000-0003-0754-4193" } ] }, "title": "Interactions Between the Leading Edge Vortex and Sweeping Jet Actuators on a Simple Swept Wing", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2022 American Institute of Aeronautics and Astronautics.", "abstract": "Highly three-dimensional vortical structures and flow separation phenomena present on swept back wings result in complex lift, drag, and pitching moment characteristics. While this may create challenges in the traditional aircraft design process, it provides a promising platform for integrating active flow control (AFC). Subsonic wind tunnel investigations are performed on a highly configurable swept wing model equipped with a spanwise array of sweeping jet actuators at 80% chord. Relating force balance measurements and surface tuft visualizations shed light on how oscillatory blowing interacts with various flow structures over a wide range of geometric and actuator configurations. We show that the lift-enhancing capabilities of AFC is closely related to the strength of vortex lift. We also demonstrate that the unstable pitch behavior of highly swept wings can be mitigated through AFC, significantly extending the flight regime over which the aircraft is trimmed. The optimal actuator distribution depends on the control objective and type of flow conditions present. Detailed understanding of these flow interaction mechanisms will be crucial for effective utilization of AFC technology on future swept wing aircraft.", "date": "2022-01-03", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2022-2426", "id_number": "CaltechAUTHORS:20220210-928472000", "isbn": "978-1-62410-631-6", "book_title": "AIAA SCITECH 2022 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220210-928472000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2022-2426", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2022-2426", "pub_year": "2022", "author_list": "Oshima, Emile; Wygnanski, Israel J.; et el." }, { "id": "https://authors.library.caltech.edu/records/rxfxj-kd732", "eprint_id": 113382, "eprint_status": "archive", "datestamp": "2023-08-20 06:28:14", "lastmod": "2023-10-23 15:34:43", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ubamanyu-Kanthasamy", "name": { "family": "Ubamanyu", "given": "Kanthasamy" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Micromechanics Modeling of Time-dependent Failure of Stowed High-strain Composite Structures", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2022 by Uba K Ubamanyu and Sergio Pellegrino. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.", "abstract": "Deployable structures made of thin-ply carbon fiber-reinforced composites are of interest due to their high stiffness to weight ratio, high packaging efficiency, and ability to deploy by the release of stored strain energy. For most applications, the largest strains are applied for the longest time during stowage, and viscoelastic polymers in these fiber-reinforced composites are prone to time-dependent deformation growth and rupture. This paper presents a study of the time-dependent deformation growth and time-dependent failure mechanisms using a micromechanics-based 3D finite element model representation of the composite. The study is focused on a repeating unit cell of a cross-ply carbon fiber laminate consisting of linear-elastic transversely isotropic fibers embedded in a linear viscoelastic matrix. A parametric study of initial fiber misalignment angle and its influence on the deformation growth and time to rupture is presented.", "date": "2022-01-03", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2022-0649", "id_number": "CaltechAUTHORS:20220210-928345000", "isbn": "978-1-62410-631-6", "book_title": "AIAA SCITECH 2022 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220210-928345000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2022-0649", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2022-0649", "pub_year": "2022", "author_list": "Ubamanyu, Kanthasamy and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/m9qh5-7v317", "eprint_id": 113389, "eprint_status": "archive", "datestamp": "2023-08-20 06:28:37", "lastmod": "2023-10-23 15:34:54", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Madhusudanan-Anagha", "name": { "family": "Madhusudanan", "given": "Anagha" } }, { "id": "McKeon-B-J", "name": { "family": "McKeon", "given": "Beverley J." }, "orcid": "0000-0003-4220-1583" } ] }, "title": "Stochastic forcing to a linearized Navier-Stokes based model for laminar compressible boundary layers", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2022 by the American Institute of Aeronautics and Astronautics, Inc.", "abstract": "We consider a linearized Navier\u2013Stokes based model for compressible laminar boundary layers and study the response of these equations to stochastic white-in-time forcing. In particular we look at the different components of the forcing and the response of this linear model with the aim of understanding how the different mechanisms captured by the model change with increasing compressibility effects. We therefore analyze the response of the linear operator to individual components of forcing, i.e. the forcing to each of the momentum equations, the continuity and the energy equations of the linear operator. We also analyze the response obtained in the three components of velocity, in density and in temperature individually. For a fixed Reynolds number of Re=400, we consider Mach numbers ranging between Ma=0.05 and Ma=10 and different wall-cooling ratios. We find that, for all the Mach numbers considered here, the most amplified structures are the streamwise streaks forced by streamwise vortices. Previous studies have shown that these modes are highly amplified in the incompressible regime as well. However, as the Mach number increases, the contribution of the streamwise velocity to these streaks decrease, and the contribution of density and temperature to the streaks increase. Finally, we briefly look at the resolvent operator of the flow, and find that all the components of the forcing are important for the amplification of the Mach waves of the flow, and these modes are not captured by the stochastically forced model.", "date": "2022-01-03", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2022-1370", "id_number": "CaltechAUTHORS:20220210-928407000", "isbn": "978-1-62410-631-6", "book_title": "AIAA SCITECH 2022 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220210-928407000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2022-1370", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2022-1370", "pub_year": "2022", "author_list": "Madhusudanan, Anagha and McKeon, Beverley J." }, { "id": "https://authors.library.caltech.edu/records/7pahy-q1y75", "eprint_id": 113379, "eprint_status": "archive", "datestamp": "2023-08-20 06:28:04", "lastmod": "2023-10-23 15:34:27", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Tang-Ellande", "name": { "family": "Tang", "given": "Ellande" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Experimental Studies of Propeller-Wing Interactions in Transition from Hover to Forward Flight", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2022 by the American Institute of Aeronautics and Astronautics, Inc.", "abstract": "The increasing popularity of Vertical Takeoff and Landing (VTOL) Aircraft in recent years combined with the electrification of propulsion has led to a variety of new configurations in aircraft design. The arrangement of propellers relative to the lifting surfaces introduces aerodynamic interactions that have been less studied in literature. This work outlines a test assembly designed specifically to study the effect of various geometries and their interactions. The assembly is composed of multiple independent subsystems which work in tandem to study the aerodynamic interactions in hover and transition flight. The data show that sub-optimal placement of the propeller can have a significant impact on the performance of the wing, even potentially completely negating the wing's lift at low speeds.", "date": "2022-01-03", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2022-0018", "id_number": "CaltechAUTHORS:20220210-927992000", "isbn": "978-1-62410-631-6", "book_title": "AIAA SCITECH 2022 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220210-927992000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2022-0018", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2022-0018", "pub_year": "2022", "author_list": "Tang, Ellande and Chung, Soon-Jo" }, { "id": "https://authors.library.caltech.edu/records/50z7m-n0b05", "eprint_id": 113417, "eprint_status": "archive", "datestamp": "2023-08-20 06:17:27", "lastmod": "2023-10-23 15:36:53", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Singh-Sumeet", "name": { "family": "Singh", "given": "Sumeet" } }, { "id": "Tsukamoto-Hiroyasu", "name": { "family": "Tsukamoto", "given": "Hiroyasu" }, "orcid": "0000-0002-6337-2667" }, { "id": "Lopez-Brett-T", "name": { "family": "Lopez", "given": "Brett T." } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Slotine-Jean-Jacques-E", "name": { "family": "Slotine", "given": "Jean-Jacques" }, "orcid": "0000-0002-7161-7812" } ] }, "title": "Safe Motion Planning with Tubes and Contraction Metrics", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2021 IEEE.", "abstract": "The recent proliferation of model predictive control (MPC) in safety-critical systems has placed additional emphasis on developing algorithms that have strict performance guarantees despite the presence of modeling error or external disturbances. This tutorial summarizes key results of combining contraction theory with MPC to enable provably-safe motion planning for robotic and aerospace systems. After a brief review of control contraction metrics, we summarize the fundamental result that any closed-loop contracting system has an associated invariant tube centered around a desired trajectory. It is then shown how these tubes can be systematically incorporated into the motion planning problem as an additional safety margin for systems with uncertain dynamics. Finally, several future research directions are discussed.", "date": "2021-12-14", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "2943-2948", "id_number": "CaltechAUTHORS:20220210-721904000", "isbn": "978-1-6654-3659-5", "book_title": "2021 60th IEEE Conference on Decision and Control (CDC)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220210-721904000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/cdc45484.2021.9682865", "pub_year": "2021", "author_list": "Singh, Sumeet; Tsukamoto, Hiroyasu; et el." }, { "id": "https://authors.library.caltech.edu/records/ve11k-pb847", "eprint_id": 113416, "eprint_status": "archive", "datestamp": "2023-08-20 06:17:20", "lastmod": "2023-10-23 15:36:47", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Tsukamoto-Hiroyasu", "name": { "family": "Tsukamoto", "given": "Hiroyasu" }, "orcid": "0000-0002-6337-2667" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Slotine-Jean-Jacques-E", "name": { "family": "Slotine", "given": "Jean-Jacques" }, "orcid": "0000-0002-7161-7812" }, { "id": "Fan-Chuchu", "name": { "family": "Fan", "given": "Chuchu" }, "orcid": "0000-0003-4671-233X" } ] }, "title": "A Theoretical Overview of Neural Contraction Metrics for Learning-based Control with Guaranteed Stability", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2021 IEEE.\n\nAccepted Version - 2110.00693.pdf
", "abstract": "This paper presents a theoretical overview of a Neural Contraction Metric (NCM): a neural network model of an optimal contraction metric and corresponding differential Lyapunov function, the existence of which is a necessary and sufficient condition for incremental exponential stability of non-autonomous nonlinear system trajectories. Its innovation lies in providing formal robustness guarantees for learning-based control frameworks, utilizing contraction theory as an analytical tool to study the nonlinear stability of learned systems via convex optimization. In particular, we rigorously show in this paper that, by regarding modeling errors of the learning schemes as external disturbances, the NCM control is capable of obtaining an explicit bound on the distance between a time-varying target trajectory and perturbed solution trajectories, which exponentially decreases with time even under the presence of deterministic and stochastic perturbation. These useful features permit simultaneous synthesis of a contraction metric and associated control law by a neural network, thereby enabling real-time computable and probably robust learning-based control for general control-affine nonlinear systems.", "date": "2021-12-14", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "2949-2954", "id_number": "CaltechAUTHORS:20220210-721895000", "isbn": "978-1-6654-3659-5", "book_title": "2021 60th IEEE Conference on Decision and Control (CDC)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220210-721895000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/cdc45484.2021.9682859", "primary_object": { "basename": "2110.00693.pdf", "url": "https://authors.library.caltech.edu/records/ve11k-pb847/files/2110.00693.pdf" }, "pub_year": "2021", "author_list": "Tsukamoto, Hiroyasu; Chung, Soon-Jo; et el." }, { "id": "https://authors.library.caltech.edu/records/a5d5g-vg404", "eprint_id": 109052, "eprint_status": "archive", "datestamp": "2023-08-20 06:15:46", "lastmod": "2023-10-23 17:31:56", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Tsukamoto-Hiroyasu", "name": { "family": "Tsukamoto", "given": "Hiroyasu" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Slotine-Jean-Jacques-E", "name": { "family": "Slotine", "given": "Jean-Jacques" }, "orcid": "0000-0002-7161-7812" } ] }, "title": "Learning-based Adaptive Control using Contraction Theory", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2021 IEEE. \n\nThis work was in part funded by the Jet Propulsion Laboratory, California Institute of Technology. \n\nCode: https://github.com/astrohiro/ancm.\n\nSubmitted - 2103.02987.pdf
", "abstract": "Adaptive control is subject to stability and performance issues when a learned model is used to enhance its performance. This paper thus presents a deep learning-based adaptive control framework for nonlinear systems with multiplicatively-separable parametrization, called adaptive Neural Contraction Metric (aNCM). The aNCM approximates real-time optimization for computing a differential Lyapunov function and a corresponding stabilizing adaptive control law by using a Deep Neural Network (DNN). The use of DNNs permits real-time implementation of the control law and broad applicability to a variety of nonlinear systems with parametric and nonparametric uncertainties. We show using contraction theory that the aNCM ensures exponential boundedness of the distance between the target and controlled trajectories in the presence of parametric uncertainties of the model, learning errors caused by aNCM approximation, and external disturbances. Its superiority to the existing robust and adaptive control methods is demonstrated using a cart-pole balancing model.", "date": "2021-12-14", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "2533-2538", "id_number": "CaltechAUTHORS:20210510-141344204", "isbn": "978-1-6654-3659-5", "book_title": "2021 60th IEEE Conference on Decision and Control (CDC)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210510-141344204", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "JPL/Caltech" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/CDC45484.2021.9683435", "primary_object": { "basename": "2103.02987.pdf", "url": "https://authors.library.caltech.edu/records/a5d5g-vg404/files/2103.02987.pdf" }, "pub_year": "2021", "author_list": "Tsukamoto, Hiroyasu; Chung, Soon-Jo; et el." }, { "id": "https://authors.library.caltech.edu/records/44ft3-jg113", "eprint_id": 113484, "eprint_status": "archive", "datestamp": "2023-08-20 06:12:18", "lastmod": "2023-10-23 15:23:34", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Fikes-Austin-C", "name": { "family": "Fikes", "given": "Austin" }, "orcid": "0000-0003-4889-5782" }, { "id": "Mizrahi-Oren-S", "name": { "family": "Mizrahi", "given": "Oren S." }, "orcid": "0000-0003-4271-8822" }, { "id": "Truong-Alan", "name": { "family": "Truong", "given": "Alan" } }, { "id": "Wiesem\u00fcller-Fabian", "name": { "family": "Wiesem\u00fcller", "given": "Fabian" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" }, { "id": "Hajimiri-A", "name": { "family": "Hajimiri", "given": "Ali" }, "orcid": "0000-0001-6736-8019" } ] }, "title": "Fully Collapsible Lightweight Dipole Antennas", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2021 IEEE.", "abstract": "Flexible, deployable phased arrays enable novel and diverse applications but necessitate similarly flexible radiators. Here we present a light and flexible 10GHz dipole antenna, which is co-cured to a glass-fiber composite and suited for flexible phased arrays. The antennas are designed to dynamically conform to new array shapes and be flexible enough to fold completely flat and pop back up upon deployment. We employ a pop-up dipole with a capacitive fingers feed for impedance matching that is highly robust against manufacturing errors. Upon deployment, the antennas exhibit a \u221210 dB-bandwidth >1.5 GHz and >110\u00b0 half-power beam width single lobe pattern suitable for beamforming.", "date": "2021-12-04", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "545-546", "id_number": "CaltechAUTHORS:20220217-686367000", "isbn": "978-1-7281-4670-6", "book_title": "2021 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting (APS/URSI)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220217-686367000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Space-Solar-Power-Project" } ] }, "doi": "10.1109/aps/ursi47566.2021.9704302", "pub_year": "2021", "author_list": "Fikes, Austin; Mizrahi, Oren S.; et el." }, { "id": "https://authors.library.caltech.edu/records/4897p-pqx30", "eprint_id": 113575, "eprint_status": "archive", "datestamp": "2023-08-20 06:08:54", "lastmod": "2023-10-23 23:07:12", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Shi-Guanya", "name": { "family": "Shi", "given": "Guanya" }, "orcid": "0000-0002-9075-3705" }, { "id": "Azizzadenesheli-Kamyar", "name": { "family": "Azizzadenesheli", "given": "Kamyar" }, "orcid": "0000-0001-8507-1868" }, { "id": "O'Connell-Michael", "name": { "family": "O'Connell", "given": "Michael" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Yue-Yisong", "name": { "family": "Yue", "given": "Yisong" }, "orcid": "0000-0001-9127-1989" } ] }, "title": "Meta-Adaptive Nonlinear Control: Theory and Algorithms", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2021 Neural Information Processing Systems Foundation, Inc. \n\nThis project was supported in part by funding from Raytheon and DARPA PAI, with additional support for Guanya Shi provided by the Simoudis Discovery Prize. There is no conflict of interest.\n\nPublished - NeurIPS-2021-meta-adaptive-nonlinear-control-theory-and-algorithms-Paper.pdf
Accepted Version - 2106.06098.pdf
Supplemental Material - NeurIPS-2021-meta-adaptive-nonlinear-control-theory-and-algorithms-Supplemental.pdf
", "abstract": "We present an online multi-task learning approach for adaptive nonlinear control, which we call Online Meta-Adaptive Control (OMAC). The goal is to control a nonlinear system subject to adversarial disturbance and unknown environment-dependent nonlinear dynamics, under the assumption that the environment-dependent dynamics can be well captured with some shared representation. Our approach is motivated by robot control, where a robotic system encounters a sequence of new environmental conditions that it must quickly adapt to. A key emphasis is to integrate online representation learning with established methods from control theory, in order to arrive at a unified framework that yields both control-theoretic and learning-theoretic guarantees. We provide instantiations of our approach under varying conditions, leading to the first non-asymptotic end-to-end convergence guarantee for multi-task nonlinear control. OMAC can also be integrated with deep representation learning. Experiments show that OMAC significantly outperforms conventional adaptive control approaches which do not learn the shared representation, in inverted pendulum and 6-DoF drone control tasks under varying wind conditions.", "date": "2021-12", "date_type": "published", "publisher": "Neural Information Processing Systems Foundation, Inc.", "id_number": "CaltechAUTHORS:20220224-200754768", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220224-200754768", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Raytheon Company" }, { "agency": "Defense Advanced Research Projects Agency (DARPA)" }, { "agency": "Simoudis Discovery Prize (Caltech)" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Center-for-Autonomous-Systems-and-Technologies-(CAST)" } ] }, "doi": "10.48550/arXiv.2106.06098", "primary_object": { "basename": "2106.06098.pdf", "url": "https://authors.library.caltech.edu/records/4897p-pqx30/files/2106.06098.pdf" }, "related_objects": [ { "basename": "NeurIPS-2021-meta-adaptive-nonlinear-control-theory-and-algorithms-Paper.pdf", "url": "https://authors.library.caltech.edu/records/4897p-pqx30/files/NeurIPS-2021-meta-adaptive-nonlinear-control-theory-and-algorithms-Paper.pdf" }, { "basename": "NeurIPS-2021-meta-adaptive-nonlinear-control-theory-and-algorithms-Supplemental.pdf", "url": "https://authors.library.caltech.edu/records/4897p-pqx30/files/NeurIPS-2021-meta-adaptive-nonlinear-control-theory-and-algorithms-Supplemental.pdf" } ], "pub_year": "2021", "author_list": "Shi, Guanya; Azizzadenesheli, Kamyar; et el." }, { "id": "https://authors.library.caltech.edu/records/afv6z-wgc92", "eprint_id": 110683, "eprint_status": "archive", "datestamp": "2023-08-20 04:30:06", "lastmod": "2023-10-20 23:13:46", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Girard-Julian", "name": { "family": "Girard", "given": "Julian" }, "orcid": "0000-0002-8101-015X" }, { "id": "Finch-Peter-M", "name": { "family": "Finch", "given": "Peter M." } }, { "id": "Schwartz-Tal", "name": { "family": "Schwartz", "given": "Tal" } }, { "id": "Yu-Wesley", "name": { "family": "Yu", "given": "Wesley" }, "orcid": "0000-0002-1133-3199" }, { "id": "Strand-Christopher-L", "name": { "family": "Strand", "given": "Christopher L." }, "orcid": "0000-0002-4112-6668" }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "Joanna M." }, "orcid": "0000-0003-3129-5035" }, { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "Hans G." }, "orcid": "0000-0002-4903-8419" }, { "id": "Hanson-Ronald-K", "name": { "family": "Hanson", "given": "Ronald K." }, "orcid": "0000-0002-8030-5327" } ] }, "title": "Characterization of the T5 Reflected Shock Tunnel Freestream Temperature, Velocity, and Composition using Laser Absorption Spectroscopy", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2021 by Julian J. Girard, Peter M. Finch. Published by the American Institute of Aeronautics and Astronautics, Inc.", "abstract": "We report on measurements of rotational and vibrational temperature, velocity, and concentrations of nitric oxide (NO), carbon monoxide (CO), water (H\u2082O), and potassium (K) in freestream flows generated by the T5 reflected shock tunnel facility at Caltech. Quantities were measured at a rate of 50 kHz by Tunable Diode Laser Absorption Spectroscopy (TDLAS) using four quantum cascade lasers (QCL) and one distributed feedback diode laser (DFB) simultaneously to sample a large collection of resolved rovibrational transitions of NO, CO and H\u2082O, and an electronic transition of K (D1). To isolate core flow measurements from the shear flow surrounding it, flow cutters (optical arms) were designed. Two sets of the optical arms with differing optical path lengths (13 cm and 23 cm) were used to assess the uniformity of quantities across the freestream core. Additionally, using angled beams (i.e. with nonzero flow-wise propagation), the flow velocity in the core was measured using laser Doppler velocimetry. A total of 9 experiments (\"shots\") were operated in this study, spanning 4 different nominal conditions with total reservoir enthalpies ranging from 8 MJ/kg to 21 MJ/kg, freestream densities ranging from 0.012 kg/m3 to 0.040 kg/m\u00b3, and flow velocities ranging from 3.5 km/s to 5.5 km/s. Measurements of the freestream generally suggest thermal equilibrium of the rotational and vibrational modal temperatures for both NO and CO. We compare temperature and NO concentration measurements with predictions from two-temperature, 5 species air simulations and find reasonable agreement at conditions with total enthalpy ~ 8 MJ/kg, but over-prediction in both temperature and NO concentration at conditions with total enthalpy ~ 18 MJ/kg. Potassium (K) was also detected in the freestream in many shots, enabling measurement of translational temperature and total static pressure from lineshape, but measurable concentrations were found to be transient and oscillatory.", "date": "2021-08", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2021-3525", "id_number": "CaltechAUTHORS:20210901-150652306", "isbn": "978-1-62410-611-8", "book_title": "AIAA Propulsion and Energy 2021 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210901-150652306", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2021-3525", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2021-3525", "pub_year": "2021", "author_list": "Girard, Julian; Finch, Peter M.; et el." }, { "id": "https://authors.library.caltech.edu/records/5v7t0-d3a75", "eprint_id": 110682, "eprint_status": "archive", "datestamp": "2023-08-20 04:30:03", "lastmod": "2023-10-20 23:13:50", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Schwartz-Tal", "name": { "family": "Schwartz", "given": "Tal" } }, { "id": "Girard-Julian", "name": { "family": "Girard", "given": "Julian" }, "orcid": "0000-0002-8101-015X" }, { "id": "Finch-Peter-M", "name": { "family": "Finch", "given": "Peter M." } }, { "id": "Yu-Wesley", "name": { "family": "Yu", "given": "Wesley" }, "orcid": "0000-0002-1133-3199" }, { "id": "Lawson-Joel-M", "name": { "family": "Lawson", "given": "Joel M." }, "orcid": "0000-0002-3042-0909" }, { "id": "Strand-Christopher-L", "name": { "family": "Strand", "given": "Christopher L." }, "orcid": "0000-0002-4112-6668" }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "Joanna M." }, "orcid": "0000-0003-3129-5035" }, { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "Hans G." }, "orcid": "0000-0002-4903-8419" }, { "id": "Hanson-Ronald-K", "name": { "family": "Hanson", "given": "Ronald K." }, "orcid": "0000-0002-8030-5327" } ] }, "title": "Characterization of the Caltech Hypervelocity Expansion Tube via Tunable Diode Laser Absorption Spectroscopy", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2021 by the American Institute of Aeronautics and Astronautics, Inc.", "abstract": "We report on measurements of freestream velocity in the Caltech Hypervelocity Expansion Tube (HET) facility. A novel diagnostic was developed based on velocimetry with Tunable Diode Laser Absorption Spectroscopy (TDLAS) targeting the D1 line of nascent atomic potassium. Two experiments at the same nominal condition showed steady flow velocity during the test time and strong agreement between experiments, but a higher velocity than expected from 1D inviscid calculations and preliminary viscous simulations. The goal of these experiments is the characterization of freestream flow conditions in the HET. Future efforts will perform this velocity characterization at additional facility conditions, measure freestream gas state properties, and reduce the measurement uncertainty due to beam alignment.", "date": "2021-08", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2021-3524", "id_number": "CaltechAUTHORS:20210901-150138936", "isbn": "978-1-62410-611-8", "book_title": "AIAA Propulsion and Energy 2021 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210901-150138936", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2021-3524", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2021-3524", "pub_year": "2021", "author_list": "Schwartz, Tal; Girard, Julian; et el." }, { "id": "https://authors.library.caltech.edu/records/dpc41-x5112", "eprint_id": 110417, "eprint_status": "archive", "datestamp": "2023-08-20 03:04:34", "lastmod": "2023-10-20 23:15:34", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Tsukamoto-Hiroyasu", "name": { "family": "Tsukamoto", "given": "Hiroyasu" }, "orcid": "0000-0002-6337-2667" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Slotine-Jean-Jacques-E", "name": { "family": "Slotine", "given": "Jean-Jacques E." }, "orcid": "0000-0002-7161-7812" } ] }, "title": "Neural Stochastic Contraction Metrics for Learning-based Control and Estimation", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Machine learning, Stochastic optimal control, Observers for nonlinear systems", "note": "\u00a9 2021 AACC. \n\nThis work was funded in part by the Raytheon Company and benefited from discussions with Nicholas Boffi and Quang-Cuong Pham.", "abstract": "We present Neural Stochastic Contraction Metrics (NSCM), a new design framework for provably-stable learning-based control and estimation for a class of stochastic nonlinear systems. It uses a spectrally-normalized deep neural network to construct a contraction metric and its differential Lyapunov function, sampled via simplified convex optimization in the stochastic setting. Spectral normalization constrains the state-derivatives of the metric to be Lipschitz continuous, thereby ensuring exponential boundedness of the mean squared distance of system trajectories under stochastic disturbances. The trained NSCM model allows autonomous systems to approximate optimal stable control and estimation policies in real-time, and outperforms existing nonlinear control and estimation techniques including the state-dependent Riccati equation, iterative LQR, EKF, and the deterministic NCM, as shown in simulation results.", "date": "2021-05", "date_type": "published", "publisher": "IEEE", "pagerange": "1275-1280", "id_number": "CaltechAUTHORS:20210825-150704832", "isbn": "978-1-6654-4197-1", "book_title": "2021 American Control Conference (ACC)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210825-150704832", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Raytheon Company" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Center-for-Autonomous-Systems-and-Technologies-(CAST)" } ] }, "doi": "10.23919/acc50511.2021.9482701", "pub_year": "2021", "author_list": "Tsukamoto, Hiroyasu; Chung, Soon-Jo; et el." }, { "id": "https://authors.library.caltech.edu/records/x5gn0-f6y92", "eprint_id": 111261, "eprint_status": "archive", "datestamp": "2023-08-20 02:07:59", "lastmod": "2023-10-23 20:28:37", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Matsuka-Kai", "name": { "family": "Matsuka", "given": "Kai" }, "orcid": "0000-0003-2116-9756" }, { "id": "Santamaria-Navarro-Angel", "name": { "family": "Santamaria-Navarro", "given": "Angel" } }, { "id": "Capuano-Vincenzo", "name": { "family": "Capuano", "given": "Vincenzo" }, "orcid": "0000-0002-6886-5719" }, { "id": "Harvard-Alexei", "name": { "family": "Harvard", "given": "Alexei" } }, { "id": "Rahmani-Amir", "name": { "family": "Rahmani", "given": "Amir" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Collaborative Pose Estimation of an Unknown Target Using Multiple Spacecraft", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2021 IEEE. \n\nKai Matsuka was supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE 1745301. Vincenzo Capuano was supported by the Swiss National Science Foundation. Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. Copyright 2020 California Institute of Technology. U.S. Government sponsorship acknowledged.\n\nPublished - Collaborative_Pose_Estimation_of_an_Unknown_Target_Using_Multiple_Spacecraft.pdf
", "abstract": "A reliable method for estimating the pose of an unknown and uncooperative space target using monocular vision remains an open problem. Vision-based pose determination is challenging due to factors such as harsh lighting conditions, rotational dynamics of the target, and scale ambiguity of the monocular camera. To address these challenges, we propose a novel collaborative pose determination algorithm called Multi-Spacecraft Simultaneous Estimation of Pose and Shape algorithm or M-SEPS. Within M-SEPS, a team of chaser spacecraft, each equipped with a monocular camera, exchange information over a local network to jointly estimate the relative kinematic state of the target and its sparse shape landmarks. In this approach, each spacecraft processes its images and extracts its own set of visual keypoints in parallel. Then, the team uses the local network to jointly estimate the target pose and shape in a distributed fashion by applying the consensus algorithm over the inter-spacecraft communication links. We validate our algorithm using simulations of relative orbits and observations captured by each chaser spacecraft. To the best of the authors' knowledge, this is the first cooperative vision-based algorithm for estimating the pose and shape of a space object by means of an arbitrary number of spacecraft.", "date": "2021-03", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "1-11", "id_number": "CaltechAUTHORS:20211007-145642151", "isbn": "978-1-7281-7436-5", "book_title": "2021 IEEE Aerospace Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20211007-145642151", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF Graduate Research Fellowship", "grant_number": "DGE-1745301" }, { "agency": "Swiss National Science Foundation (SNSF)" }, { "agency": "NASA/JPL/Caltech" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/aero50100.2021.9438352", "primary_object": { "basename": "Collaborative_Pose_Estimation_of_an_Unknown_Target_Using_Multiple_Spacecraft.pdf", "url": "https://authors.library.caltech.edu/records/x5gn0-f6y92/files/Collaborative_Pose_Estimation_of_an_Unknown_Target_Using_Multiple_Spacecraft.pdf" }, "pub_year": "2021", "author_list": "Matsuka, Kai; Santamaria-Navarro, Angel; et el." }, { "id": "https://authors.library.caltech.edu/records/hhy45-ezd85", "eprint_id": 107429, "eprint_status": "archive", "datestamp": "2023-08-20 01:22:42", "lastmod": "2023-10-23 15:53:16", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Marshall-Michael-A", "name": { "family": "Marshall", "given": "Michael" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Reduced-Order Modeling for Flexible Spacecraft Deployment and Dynamics", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2021 by Michael A. Marshall and Sergio Pellegrino. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission. \n\nM. A. Marshall was supported by a NASA Space Technology Research Fellowship. Financial support from the California Institute of Technology (Caltech) Space Solar Power Project is also gratefully acknowledged. The authors thank W. Keats Wilkie and F. Gianfranco Canales Escobedo for the many helpful discussions.\n\nAccepted Version - Marshall-Pellegrino-2021.pdf
", "abstract": "The present work investigates reduced-order modeling for ultralight, packageable, and self-deployable spacecraft where reduced-order models (ROMs) are required to simulate deployment, structural dynamics during spacecraft maneuvers, and for real-time applications in trajectory optimization and control. In these contexts, ultralight, flexible spacecraft dynamics are characterized by geometrically nonlinear structural deformations combined with large rigid body motions. An approach based on proper orthogonal decomposition (POD), energy-conserving sampling and weighting (ECSW), and a floating frame of reference (FFR) is proposed to construct accurate and efficient ROMs. The proposed approach is then tested on a benchmark problem that involves geometrically nonlinear deformations, large rigid body motions, and strain energy release during dynamic snap-back, the last of which is analogous to the energy release during deployment. The resulting ROM for this benchmark problem is approximately 20% the size of the original full-order model with no appreciable loss of accuracy.", "date": "2021-01-11", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2021-1385", "id_number": "CaltechAUTHORS:20210112-105611714", "isbn": "9781624106095", "book_title": "AIAA Scitech 2021 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210112-105611714", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA Space Technology Research Fellowship" }, { "agency": "Space Solar Power Project" } ] }, "other_numbering_system": { "items": [ { "id": "2021-1385", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Space-Solar-Power-Project" } ] }, "doi": "10.2514/6.2021-1385", "primary_object": { "basename": "Marshall-Pellegrino-2021.pdf", "url": "https://authors.library.caltech.edu/records/hhy45-ezd85/files/Marshall-Pellegrino-2021.pdf" }, "pub_year": "2021", "author_list": "Marshall, Michael and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/3q728-qts15", "eprint_id": 107426, "eprint_status": "archive", "datestamp": "2023-08-20 01:22:30", "lastmod": "2023-10-23 15:53:07", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Clark-Ivan", "name": { "family": "Clark", "given": "Ivan" } }, { "id": "Bollt-Scott", "name": { "family": "Bollt", "given": "Scott" } }, { "id": "Krier-William", "name": { "family": "Krier", "given": "William" } } ] }, "title": "Wind Lidars for Aero-Assisted Entry, Descent, and Landing on Mars", "ispublished": "unpub", "full_text_status": "public", "note": "This material is declared a work of the U.S. Government and is not subject to copyright protection in the United States.", "abstract": "NASA seeks to safely and consistently deliver 20 metric tons of payload to within 50m of the intended location on Mars. A study has been conducted to evaluate the utility of wind lidars to aid in aero-assisted entry, descent, and precision landing of vehicles carrying these payloads. Numerical simulation found that coherent-Doppler, infrared, aerosol-backscatter wind lidars on the Martian surface can measure winds nominally over a 15km radius hemisphere using eye-safe laser energies and optical apertures similar to those commercially available for terrestrial airport support. Such ground-based wind measurements around the target delivery site are useful for determining when to initiate atmospheric entry. Initial analyses of direct-Doppler, ultraviolet, molecular-backscatter wind lidars demonstrate forward-looking measurement of wind speed, atmospheric temperature, atmospheric density, and vehicle flight attitude beyond the vehicle boundary layer. These measurements would enable controlled flight of an aero-assisted cargo vehicle to the designated landing site.", "date": "2021-01-11", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2021-1505", "id_number": "CaltechAUTHORS:20210112-105611474", "isbn": "9781624106095", "book_title": "AIAA Scitech 2021 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210112-105611474", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2021-1505", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2021-1505", "pub_year": "2021", "author_list": "Clark, Ivan; Bollt, Scott; et el." }, { "id": "https://authors.library.caltech.edu/records/3h8vn-spg81", "eprint_id": 107427, "eprint_status": "archive", "datestamp": "2023-08-20 01:22:33", "lastmod": "2023-10-23 15:53:10", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Anderson-Matthew", "name": { "family": "Anderson", "given": "Matthew" } }, { "id": "Backus-Spencer-B", "name": { "family": "Backus", "given": "Spencer B." }, "orcid": "0000-0002-6466-053X" }, { "id": "Hughes-Ery-C", "name": { "family": "Hughes", "given": "Ery" } }, { "id": "Curtis-Aaron", "name": { "family": "Curtis", "given": "Aaron" }, "orcid": "0000-0002-2942-4347" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Stolper-E-M", "name": { "family": "Stolper", "given": "Edward" }, "orcid": "0000-0001-8008-8804" } ] }, "title": "Development and Deployment of an Autonomous UAV-Borne Gas and Particulate Sample Capture System for Fumarole Sampling", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2021 by Caltech. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.", "abstract": "Volcanoes are one of the great forces of the natural world. The gases they release can reveal information about the world below us, from the structure of the planet, to the risk of an imminent eruption. Sampling these gases however is often difficult and extremely dangerous - high temperatures, hazardous gases, steep terrain and remoteness all make collecting samples a challenging endeavour. Unoccupied Aerial Vehicles (UAVs) can help reduce the risks and difficulties of measuring and sampling these gases, enabling studies of volcanic systems that were otherwise inaccessible. This paper presents the first known effort to design, develop and field test a UAV-borne Gas Capture System (UGCS) for volcanic fumarole sampling. This work includes the development of a sampling probe deployment mechanism, sample canister selection, payload-to-UAV interfacing, and a light-weight visual/thermal camera package. Operationally, the intricacies of placing a sample probe into a small fumarole opening are examined, as are the hazards of flying a UAV with a suspended load.", "date": "2021-01-11", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2021-1409", "id_number": "CaltechAUTHORS:20210112-105611577", "isbn": "9781624106095", "book_title": "AIAA Scitech 2021 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210112-105611577", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2021-1409", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.2514/6.2021-1409", "pub_year": "2021", "author_list": "Anderson, Matthew; Backus, Spencer B.; et el." }, { "id": "https://authors.library.caltech.edu/records/ex7hq-32k66", "eprint_id": 107435, "eprint_status": "archive", "datestamp": "2023-08-20 01:23:03", "lastmod": "2023-10-23 15:53:34", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Pedivellano-Antonio", "name": { "family": "Pedivellano", "given": "Antonio" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Propagation of Elastic Folds in the Deployment of Thin Shell Space Structures", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2021 by Antonio Pedivellano, Sergio Pellegrino. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.", "abstract": "This paper investigates the deployment behavior of lightweight flexible space structures consisting of thin shell components. An extensive and detailed study of a symmetrically folded structure that dynamically deploys by releasing its stored elastic energy is presented. The challenges involved with ground testing of this structure are discussed, and a suspension system that allows propagation of the elastic folds is proposed. The dynamics of two 1 m-scale structural prototypes was measured using high-speed Digital Image Correlation. It is shown that, for the tests considered, the elastic folds remain stationary and behave as elastic hinges, resulting in a symmetric and repeatable deployment. Deployment experiments in air and vacuum showed that air mass significantly affects the dynamics of the structure, slowing its deployment by 70 %. However, this effect becomes negligible if the deployable structure is not covered by a film. A finite element model of the deployment is presented. The effects of air are approximated by an added mass to the structure, calculated through simple geometric arguments. This model shows good agreement with experimental results without increasing the associated computational time.", "date": "2021-01-11", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2021-0299", "id_number": "CaltechAUTHORS:20210112-105612128", "isbn": "9781624106095", "book_title": "AIAA Scitech 2021 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210112-105612128", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2021-0299", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2021-0299", "pub_year": "2021", "author_list": "Pedivellano, Antonio and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/mqmsq-dmn57", "eprint_id": 107423, "eprint_status": "archive", "datestamp": "2023-08-20 01:22:19", "lastmod": "2023-10-23 15:52:58", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Reddy-Narravula-Harshavardhan", "name": { "family": "Reddy", "given": "Narravula Harshavardhan" }, "orcid": "0000-0003-3897-8162" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Time-efficient geometrically non-linear finite element simulations of thin shell deployable structures", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2021 by Narravula Harshavardhan Reddy and Sergio Pellegrino. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission. \n\nThis research was funded by the Space Solar Power Project at Caltech.\n\nAccepted Version - Reddy-Pellegrino_final.pdf
", "abstract": "Isogeometric analysis of thin shells can provide higher continuity and exact geometric description. It is shown in the existing literature that isogeometric analysis converges with fewer degrees of freedom than C\u2070-continuous finite elements that use Langrange polynomial shape functions, but the speed of the solutions has not been previously assessed. In this research, the geometrically nonlinear bending of a thin shell deployable structure, a tape spring is studied, using both NURBS-based and C\u2070-continuous finite elements. The complex deformation of a tape spring makes it a perfect case study to compare the computational efficiency of the mentioned techniques. The simulations are carried out in the commercial software ABAQUS and LS-DYNA, and it is found that isogeometric analysis is at least three times slower than the C\u2070-continuous finite element methods.", "date": "2021-01-11", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2021-1795", "id_number": "CaltechAUTHORS:20210112-105611267", "isbn": "9781624106095", "book_title": "AIAA Scitech 2021 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210112-105611267", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Space Solar Power Project" } ] }, "other_numbering_system": { "items": [ { "id": "2021-1795", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Space-Solar-Power-Project" } ] }, "doi": "10.2514/6.2021-1795", "primary_object": { "basename": "Reddy-Pellegrino_final.pdf", "url": "https://authors.library.caltech.edu/records/mqmsq-dmn57/files/Reddy-Pellegrino_final.pdf" }, "pub_year": "2021", "author_list": "Reddy, Narravula Harshavardhan and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/k328p-53774", "eprint_id": 107428, "eprint_status": "archive", "datestamp": "2023-08-20 01:22:38", "lastmod": "2023-10-23 15:53:13", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lee-Andrew-J", "name": { "family": "Lee", "given": "Andrew" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Cable-Stayed Architectures for Large Deployable Spacecraft", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2021 by Andrew J. Lee and Sergio Pellegrino. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission. \n\nThe authors are grateful to Dr. Martin Mikulas of the National Institute of Aerospace for sharing his experience and for insightful discussions. Financial support from the Space Solar Power Project at the California Institute of Technology is gratefully acknowledged.\n\nAccepted Version - Lee-Pellegrino_Final.pdf
", "abstract": "Cable-stayed structural architectures, which use a combination of bending and axial load-carrying modes, are potentially more efficient than structural architectures that rely only on bending. However, they are not widely used at present. In this paper, an analytical framework is established to compare the load carrying performance of cable-stayed vs. bending architectures by considering limiting conditions such as global buckling, local shell buckling, material failure, and excessive deflection. For structures of equal span, material properties, mass, and maximum deflection limit, the most efficient cable-stayed geometry is determined and its performance is compared to that of the beam. It is shown that the cable-stayed architecture is more efficient at withstanding external loads and remains optimal over the bending architecture. Design charts for optimal designs of cable-stayed structures for a range of lengths and loads are provided.", "date": "2021-01-11", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2021-1386", "id_number": "CaltechAUTHORS:20210112-105611630", "isbn": "9781624106095", "book_title": "AIAA Scitech 2021 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210112-105611630", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Space Solar Power Project" } ] }, "other_numbering_system": { "items": [ { "id": "2021-1386", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Space-Solar-Power-Project" } ] }, "doi": "10.2514/6.2021-1386", "primary_object": { "basename": "Lee-Pellegrino_Final.pdf", "url": "https://authors.library.caltech.edu/records/k328p-53774/files/Lee-Pellegrino_Final.pdf" }, "pub_year": "2021", "author_list": "Lee, Andrew and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/zqdwv-3c566", "eprint_id": 107424, "eprint_status": "archive", "datestamp": "2023-08-20 01:22:23", "lastmod": "2023-10-23 15:53:01", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Tang-Ellande", "name": { "family": "Tang", "given": "Ellande" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Experimental Model of Effects of Large Upstream Obstructions on Drone Scale Propellers", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2021 by the American Institute of Aeronautics and Astronautics, Inc.", "abstract": "Recent improvements in computer and electrical energy storage technologies among others have made small Unmanned Aerial Vehicles practical and economical across many design spaces. Recently, designs blending fixed wing and multi-copter elements have become popular as commercial products and research platforms. This configuration has a number of understudied aerodynamic interactions particularly between the rotors and other aerodynamic surfaces. Studying these interactions is key to creating effective designs and developing good models for other aspects of the system such as control and performance evaluation. This paper seeks to understand the effect of occluding the upstream of a propeller at varying distances and varying amounts. The experiments are meant to provide useful guidelines on how far one should position lifting rotors from obstructions such as wings or the fuselage or what the associated trade offs might be. The data indicate that, for large obstructions, the combined effect is significant on performance, but is also predictable regardless of propeller size and pitch, reducing to negligible at roughly one-half propelled diameter.", "date": "2021-01-11", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2021-1648", "id_number": "CaltechAUTHORS:20210112-105611355", "isbn": "9781624106095", "book_title": "AIAA Scitech 2021 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210112-105611355", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2021-1648", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2021-1648", "pub_year": "2021", "author_list": "Tang, Ellande and Chung, Soon-Jo" }, { "id": "https://authors.library.caltech.edu/records/41hz5-a9953", "eprint_id": 107434, "eprint_status": "archive", "datestamp": "2023-08-20 01:23:00", "lastmod": "2023-10-23 15:53:32", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Sharan-Nek", "name": { "family": "Sharan", "given": "Nek" }, "orcid": "0000-0002-7274-8232" }, { "id": "Bellan-J", "name": { "family": "Bellan", "given": "Josette R." }, "orcid": "0000-0001-9218-7017" } ] }, "title": "Direct numerical simulation of high-pressure free jets", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2021 by California Institute of Technology. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.", "abstract": "Understanding turbulent round-jet flow dynamics at supercritical pressures is crucial to controlling fuel-oxidizer mixing and combustion in numerous propulsion systems. To that end, direct numerical simulations (DNS) of round jets are performed to discern the differences between turbulence and mixing characteristics at atmospheric and supercritical conditions. Single-species isothermal jets, with Nitrogen (N\u2082) injected into N\u2082 at same temperature, are considered at Reynolds number (Re_{D}), based on jet diameter (D) and jet-exit velocity (U_e), of 5000. To understand mixing characteristics, a passive scalar with unity Schmidt number is transported with the flow. For supercritical conditions, the compressible flow equations with the Peng-Robinson equation of state are solved to examine the influence of thermodynamic compressibility, quantified by the compressibility factor (Z), on jet-flow dynamics. The results show that decreasing Z at a fixed supercritical ambient pressure (p_\u221e) enhances the pressure and density fluctuations (non-dimensionalized by the local mean pressure and density, respectively), but the effect on velocity fluctuations depends also on local flow dynamics characterized by mean strain rates.", "date": "2021-01-11", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2021-0550", "id_number": "CaltechAUTHORS:20210112-105612042", "isbn": "9781624106095", "book_title": "AIAA Scitech 2021 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210112-105612042", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2021-0550", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2021-0550", "pub_year": "2021", "author_list": "Sharan, Nek and Bellan, Josette R." }, { "id": "https://authors.library.caltech.edu/records/v1mwh-p4677", "eprint_id": 107430, "eprint_status": "archive", "datestamp": "2023-08-20 01:22:46", "lastmod": "2023-10-23 15:53:19", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Parziale-Nicholaus-J", "name": { "family": "Parziale", "given": "Nick J." }, "orcid": "0000-0001-9880-1727" }, { "id": "Mustafa-Muhammad-A", "name": { "family": "Mustafa", "given": "Muhammad A." }, "orcid": "0000-0002-4523-0737" }, { "id": "Shekhtman-David", "name": { "family": "Shekhtman", "given": "David" }, "orcid": "0000-0003-0648-5435" }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "Joanna M." }, "orcid": "0000-0003-3129-5035" }, { "id": "Yu-Wesley-M", "name": { "family": "Yu", "given": "Wesley M." } } ] }, "title": "Krypton Tagging Velocimetry (KTV) Investigation in the Caltech T5 Reflected-Shock Tunnel", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2021 by Nicholaus Joseph Parziale. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.", "abstract": "Results are presented for a Krypton Tagging Velocimetry (KTV) investigation of the freestream flow of the T5 reflected shock tunnel at Caltech. This KTV scheme utilizes two-photon excitation at 216.67 nm with a pulsed dye laser, followed by re-excitation at 769.4547 nm with a continuous laser diode. Results are presented for experiments performed in 97% N\u2082 / 3% Kr and 99% N\u2082 / 1% Kr gas mixtures at a unit Reynolds number of approximately 4\u00d710\u2076 1/m and a reservoir mass-specific enthalpy of approximately 5 MJ/kg. Agreement between the KTV derived velocity measurement and the computational results is excellent, within the uncertainty of the experiment.", "date": "2021-01-11", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2021-1302", "id_number": "CaltechAUTHORS:20210112-105611764", "isbn": "9781624106095", "book_title": "AIAA Scitech 2021 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210112-105611764", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2021-1302", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2021-1302", "pub_year": "2021", "author_list": "Parziale, Nick J.; Mustafa, Muhammad A.; et el." }, { "id": "https://authors.library.caltech.edu/records/nev08-17814", "eprint_id": 109127, "eprint_status": "archive", "datestamp": "2023-08-22 08:27:03", "lastmod": "2023-10-23 17:40:39", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Pedivellano-Antonio", "name": { "family": "Pedivellano", "given": "Antonio" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Deployment Dynamics of Foldable Thin Shell Space Structures", "ispublished": "unpub", "full_text_status": "public", "keywords": "Space Structures; Finite Element Modeling; Longerons; Bending Stiffness; Finite Element Software; Thin Shell Structure; Kinetic Energy; Ball Bearings; Principal Stresses; Solar Cells", "note": "\u00a9 2021 by Antonio Pedivellano, Sergio Pellegrino. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission. \n\nPublished Online: 4 Jan 2021. \n\nThe authors thank Dr. Xiaowei Deng (University of Hong Kong) for providing the Abaqus subroutine implementing the IMP membrane formulation, Alan Truong (Caltech) for building the strip prototypes used in the experiments in this paper, Charles Sommer (Caltech) for assisting with the deployment experiments in vacuum, and Fabien Royer (Caltech) for help with the bending tests of the strip prototypes. Financial support from the Space Solar Power Project at Caltech is gratefully acknowledged.\n\nAccepted Version - Pedivellano-Pellegrino-2021.pdf
", "abstract": "This paper investigates the deployment behavior of lightweight flexible space structures consisting of thin shell components. An extensive and detailed study of a symmetrically folded structure that dynamically deploys by releasing its stored elastic energy is presented. The challenges involved with ground testing of this structure are discussed, and a suspension system that allows propagation of the elastic folds is proposed. The dynamics of two 1 m-scale structural prototypes was measured using high-speed Digital Image Correlation. It is shown that, for the tests considered, the elastic folds remain stationary and behave as elastic hinges, resulting in a symmetric and repeatable deployment. Deployment experiments in air and vacuum showed that air mass significantly affects the dynamics of the structure, slowing its deployment by 70 %. However, this effect becomes negligible if the deployable structure is not covered by a film. A finite element model of the deployment is presented. The effects of air are approximated by an added mass to the structure, calculated through simple geometric arguments. This model shows good agreement with experimental results without increasing the associated computational time.", "date": "2021-01-11", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2021-0299", "id_number": "CaltechAUTHORS:20210514-081314705", "isbn": "9781624106095", "book_title": "AIAA Scitech 2021 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210514-081314705", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Space Solar Power Project" } ] }, "other_numbering_system": { "items": [ { "id": "2021-0299", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Space-Solar-Power-Project" } ] }, "doi": "10.2514/6.2021-0299", "primary_object": { "basename": "Pedivellano-Pellegrino-2021.pdf", "url": "https://authors.library.caltech.edu/records/nev08-17814/files/Pedivellano-Pellegrino-2021.pdf" }, "pub_year": "2021", "author_list": "Pedivellano, Antonio and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/y683v-rpf72", "eprint_id": 107425, "eprint_status": "archive", "datestamp": "2023-08-20 01:22:27", "lastmod": "2023-10-23 15:53:04", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Tang-Ellande", "name": { "family": "Tang", "given": "Ellande" } }, { "id": "Spieler-Patrick", "name": { "family": "Spieler", "given": "Patrick" } }, { "id": "Anderson-Matthew", "name": { "family": "Anderson", "given": "Matthew" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Design of the Next-Generation Autonomous Flying Ambulance", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2021 by the American Institute of Aeronautics and Astronautics, Inc.", "abstract": "As electric aircraft take to the skies, it is becoming common to speculate on potential niches in which to apply the technology. One promising role for these vehicles is in the medical domain, a role currently filled by helicopters. A Vertical Take-Off and Landing (VTOL) aircraft with autonomous capabilities could avoid obstacles and transport injured patients to receive critical medical care more quickly than land-based options. This paper presents the design of a novel, fully-electric VTOL aircraft designed to satisfy a medical transport mission by carrying a patient and a paramedic a moderate distance. The paper also presents a scale vehicle model that can be used to test the vehicle design and potential autonomy technologies as well as the special design considerations unique to a VTOL with fixed-wing capabilities. The resultant vehicle will represent the state-of-the-art of what is possible with existing hardware while remaining a flexible platform for autonomy research.", "date": "2021-01-11", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2021-1514", "id_number": "CaltechAUTHORS:20210112-105611407", "isbn": "9781624106095", "book_title": "AIAA Scitech 2021 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210112-105611407", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2021-1514", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2021-1514", "pub_year": "2021", "author_list": "Tang, Ellande; Spieler, Patrick; et el." }, { "id": "https://authors.library.caltech.edu/records/ygdnq-ykp98", "eprint_id": 107431, "eprint_status": "archive", "datestamp": "2023-08-20 01:22:49", "lastmod": "2023-10-23 15:53:22", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Nakka-Yashwanth-Kumar-K", "name": { "family": "Nakka", "given": "Yashwanth Kumar K." }, "orcid": "0000-0001-7897-3644" }, { "id": "H\u00f6nig-Wolfgang", "name": { "family": "H\u00f6nig", "given": "Wolfgang" }, "orcid": "0000-0002-0773-028X" }, { "id": "Choi-Changrak", "name": { "family": "Choi", "given": "Changrak" } }, { "id": "Harvard-Alexei", "name": { "family": "Harvard", "given": "Alexei" } }, { "id": "Rahmani-Amir", "name": { "family": "Rahmani", "given": "Amir" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Information-Based Guidance and Control Architecture for Multi-Spacecraft On-Orbit Inspection", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2021 by the American Institute of Aeronautics and Astronautics, Inc.", "abstract": "We present an architecture for inspection or mapping of a target spacecraft, referred to as chief, in an orbit around Earth using multiple spacecraft, referred to as deputies (or) observers, in stable Passive Relative Orbits (PROs). We use an information gain approach to directly consider the trade-off between gathered data and fuel/energy cost. The four components of our architecture are: 1) information estimation, 2) state estimation, 3) motion planning for relative orbit initialization and reconfiguration, and 4) relative orbit control. The information estimation quantifies the information gain during inspection of a spacecraft, given past and potential future poses of all spacecraft. The estimated information gain is a crucial input to the motion planner, which computes PROs and reconfiguration strategies for each of the observers to maximize the information gain from distributed observations of the target spacecraft. The resulting motion trajectories jointly consider observational coverage of the target spacecraft and fuel/energy cost. For the PRO trajectories, we design a fuel optimal attitude trajectory that minimizes rest-to-rest energy for each observer to inspect the target spacecraft. We validate our architecture in a mission simulation to visually inspect the target spacecraft.", "date": "2021-01-11", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2021-1103", "id_number": "CaltechAUTHORS:20210112-105611832", "isbn": "9781624106095", "book_title": "AIAA Scitech 2021 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210112-105611832", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2021-1103", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2021-1103", "pub_year": "2021", "author_list": "Nakka, Yashwanth Kumar K.; H\u00f6nig, Wolfgang; et el." }, { "id": "https://authors.library.caltech.edu/records/zt63z-d7141", "eprint_id": 107927, "eprint_status": "archive", "datestamp": "2023-08-20 01:16:41", "lastmod": "2023-10-23 16:20:06", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Williams-D-Elliott", "name": { "family": "Williams", "given": "D. Elliott" } }, { "id": "Dorn-Charles", "name": { "family": "Dorn", "given": "Charles" }, "orcid": "0000-0001-6516-2586" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" }, { "id": "Hajimiri-A", "name": { "family": "Hajimiri", "given": "Ali" }, "orcid": "0000-0001-6736-8019" } ] }, "title": "Origami-Inspired Shape-Changing Phased Array", "ispublished": "unpub", "full_text_status": "public", "keywords": "phased arrays, origami, adaptive arrays, aperture, patch antennas, integrated circuits", "note": "\u00a9 2020 EuMA. \n\nThe authors thank Rogers Corp. for providing substrate materials and R. Lang, B. Abiri, D. Hodge, and Y. Li for their help. This work was supported in part by the MURI Grant\nFA9550-16-1-0566 via AFOSR.\n\nPublished - 09338189.pdf
", "abstract": "In situ geometric reconfiguration of a phased array increases the diversity of radiation patterns that can be synthesized by the array. Such shape-changing phased arrays enable new applications by dynamically conforming their shapes to the geometry best suited for a given task. This work presents the design and demonstration of an origami-inspired shape-changing array built out of identical radiating tiles held in place by a mechanical backbone. The array is capable of shifting into planar, spherical, and cylindrical configurations. The benefits of such an array are analyzed by comparing the properties of different geometries and verified with measurements of the first origami-inspired shape-changing phased array.", "date": "2021-01", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "344-347", "id_number": "CaltechAUTHORS:20210205-093044804", "isbn": "9782874870590", "book_title": "2020 50th European Microwave Conference (EuMC)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210205-093044804", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-16-1-0566" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.23919/eumc48046.2021.9338189", "primary_object": { "basename": "09338189.pdf", "url": "https://authors.library.caltech.edu/records/zt63z-d7141/files/09338189.pdf" }, "pub_year": "2021", "author_list": "Williams, D. Elliott; Dorn, Charles; et el." }, { "id": "https://authors.library.caltech.edu/records/b3cvj-npn92", "eprint_id": 118582, "eprint_status": "archive", "datestamp": "2023-08-20 00:44:32", "lastmod": "2023-10-24 23:24:56", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Shi-Guanya", "name": { "family": "Shi", "given": "Guanya" }, "orcid": "0000-0002-9075-3705" }, { "id": "Lin-Yiheng", "name": { "family": "Lin", "given": "Yiheng" }, "orcid": "0000-0001-6524-2877" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Yue-Yisong", "name": { "family": "Yue", "given": "Yisong" }, "orcid": "0000-0001-9127-1989" }, { "id": "Wierman-A", "name": { "family": "Wierman", "given": "Adam" }, "orcid": "0000-0002-5923-0199" } ] }, "title": "Online Optimization with Memory and Competitive Control", "ispublished": "unpub", "full_text_status": "public", "note": "This project was supported in part by funding from Raytheon, DARPA PAI, AitF-1637598 and CNS-1518941, with additional support for Guanya Shi provided by the Simoudis Discovery Prize. \n\nWe see no ethical concerns related to the results in this paper.", "abstract": "This paper presents competitive algorithms for a novel class of online optimization problems with memory. We consider a setting where the learner seeks to minimize the sum of a hitting cost and a switching cost that depends on the previous p decisions. This setting generalizes Smoothed Online Convex Optimization. The proposed approach, Optimistic Regularized Online Balanced Descent, achieves a constant, dimension-free competitive ratio. Further, we show a connection between online optimization with memory and online control with adversarial disturbances. This connection, in turn, leads to a new constant-competitive policy for a rich class of online control problems.", "date": "2020-12", "date_type": "published", "publisher": "Neural Information Processing Foundation", "place_of_pub": "La Jolla, CA", "pagerange": "1-12", "id_number": "CaltechAUTHORS:20221222-183256740", "isbn": "9781713829546", "book_title": "34th Conference on Neural Information Processing Systems (NeurIPS 2020)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20221222-183256740", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Raytheon Company" }, { "agency": "Defense Advanced Research Projects Agency (DARPA)" }, { "agency": "NSF", "grant_number": "CCF-1637598" }, { "agency": "NSF", "grant_number": "CNS-1518941" }, { "agency": "Simoudis Discovery Prize" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Larochelle-Hugo", "name": { "family": "Larochelle", "given": "Hugo" } }, { "id": "Ranzato-M", "name": { "family": "Ranzato", "given": "M." } }, { "id": "Hadsell-R", "name": { "family": "Hadsell", "given": "R." } }, { "id": "Balcan-M-F", "name": { "family": "Balcan", "given": "M. F." } }, { "id": "Lin-H", "name": { "family": "Lin", "given": "H." } } ] }, "pub_year": "2020", "author_list": "Shi, Guanya; Lin, Yiheng; et el." }, { "id": "https://authors.library.caltech.edu/records/k462b-vce11", "eprint_id": 118583, "eprint_status": "archive", "datestamp": "2023-08-20 00:44:35", "lastmod": "2023-10-24 23:25:18", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Yu-Chenkai", "name": { "family": "Yu", "given": "Chenkai" }, "orcid": "0000-0001-8683-7773" }, { "id": "Shi-Guanya", "name": { "family": "Shi", "given": "Guanya" }, "orcid": "0000-0002-9075-3705" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Yue-Yisong", "name": { "family": "Yue", "given": "Yisong" }, "orcid": "0000-0001-9127-1989" }, { "id": "Wierman-A", "name": { "family": "Wierman", "given": "Adam" }, "orcid": "0000-0002-5923-0199" } ] }, "title": "The Power of Predictions in Online Control", "ispublished": "unpub", "full_text_status": "public", "note": "This project was supported in part by funding from Raytheon, DARPA PAI, AitF-1637598 and CNS-1518941, with additional support for Guanya Shi provided by the Simoudis Discovery Prize. \n\nWe see no ethical concerns related to the results in this paper.", "abstract": "We study the impact of predictions in online Linear Quadratic Regulator control with both stochastic and adversarial disturbances in the dynamics. In both settings, we characterize the optimal policy and derive tight bounds on the minimum cost and dynamic regret. Perhaps surprisingly, our analysis shows that the conventional greedy MPC approach is a near-optimal policy in both stochastic and adversarial settings. Specifically, for length-T problems, MPC requires only O(logT) predictions to reach O(1) dynamic regret, which matches (up to lower-order terms) our lower bound on the required prediction horizon for constant regret.", "date": "2020-12", "date_type": "published", "publisher": "Neural Information Processing Foundation", "place_of_pub": "La Jolla, CA", "pagerange": "1-11", "id_number": "CaltechAUTHORS:20221222-184439362", "isbn": "9781713829546", "book_title": "34th Conference on Neural Information Processing Systems (NeurIPS 2020)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20221222-184439362", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Raytheon Company" }, { "agency": "Defense Advanced Research Projects Agency (DARPA)" }, { "agency": "NSF", "grant_number": "CCF-1637598" }, { "agency": "NSF", "grant_number": "CNS-1518941" }, { "agency": "Simoudis Discovery Prize" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Larochelle-Hugo", "name": { "family": "Larochelle", "given": "Hugo" } }, { "id": "Ranzato-M", "name": { "family": "Ranzato", "given": "M." } }, { "id": "Hadsell-R", "name": { "family": "Hadsell", "given": "R." } }, { "id": "Balcan-M-F", "name": { "family": "Balcan", "given": "M. F." } }, { "id": "Lin-H", "name": { "family": "Lin", "given": "H." } } ] }, "pub_year": "2020", "author_list": "Yu, Chenkai; Shi, Guanya; et el." }, { "id": "https://authors.library.caltech.edu/records/93kdt-84m30", "eprint_id": 106497, "eprint_status": "archive", "datestamp": "2023-08-20 00:23:13", "lastmod": "2023-10-20 23:33:09", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Delaune-Jeff", "name": { "family": "Delaune", "given": "Jeff" } }, { "id": "Izraelevitz-J", "name": { "family": "Izraelevitz", "given": "Jacob" } }, { "id": "Young-L-A", "name": { "family": "Young", "given": "Larry A." } }, { "id": "Rapin-W", "name": { "family": "Rapin", "given": "William" }, "orcid": "0000-0003-4660-8006" }, { "id": "Sklyanskiy-Evgeniy", "name": { "family": "Sklyanskiy", "given": "Evgeniy" } }, { "id": "Johnson-Wayne", "name": { "family": "Johnson", "given": "Wayne" } }, { "id": "Schutte-Aaron", "name": { "family": "Schutte", "given": "Aaron" } }, { "id": "Fraeman-A-A", "name": { "family": "Fraeman", "given": "Abigail" }, "orcid": "0000-0003-4017-5158" }, { "id": "Scott-Valerie", "name": { "family": "Scott", "given": "Valerie" } }, { "id": "Leake-Carl", "name": { "family": "Leake", "given": "Carl" } }, { "id": "Ballesteros-Erik", "name": { "family": "Ballesteros", "given": "Erik" } }, { "id": "Withrow-Shannah", "name": { "family": "Withrow", "given": "Shannah" } }, { "id": "Bhagwat-Raghav", "name": { "family": "Bhagwat", "given": "Raghav" } }, { "id": "Cummings-Haley", "name": { "family": "Cummings", "given": "Haley" } }, { "id": "Aaron-K-M", "name": { "family": "Aaron", "given": "Kim" } }, { "id": "Veismann-M", "name": { "family": "Veismann", "given": "Marcel" } }, { "id": "Wei-Skylar", "name": { "family": "Wei", "given": "Skylar" } }, { "id": "Lee-Regina", "name": { "family": "Lee", "given": "Regina" } }, { "id": "Pabon-Madrid-L", "name": { "family": "Pabon Madrid", "given": "Luis" } }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "Morteza" }, "orcid": "0000-0003-0754-4193" }, { "id": "Burdick-J-W", "name": { "family": "Burdick", "given": "Joel" } } ] }, "title": "Motivations and Preliminary Design for Mid-Air Deployment of a Science Rotorcraft on Mars", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2020 by the American Institute of Aeronautics and Astronautics, Inc. \n\nPublished Online: 2 Nov 2020. \n\nThe research described in this paper was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). \n\nThis work was supported by JPL's Spontaneous R&TD program, and a NASA Space Technology Research Fellowship, Leake [NSTRF 2019] Grant #: 80NSSC19K1152. \n\nThe authors would like to thank Chad Edwards and Larry Matthies, from JPL's Mars Exploration Program Advanced Concepts Office, for their technical and programmatic support; as well as Theodore Tzanetos, Mars Helicopter tactical lead at JPL, for sanity checking Ingenuity's design parameters.\n\nAccepted Version - 2010.06630.pdf
", "abstract": "Mid-Air Deployment (MAD) of a rotorcraft during Entry, Descent and Landing (EDL) on Mars eliminates the need to carry a propulsion or airbag landing system. This reduces the total mass inside the aeroshell by more than 100 kg and simplifies the aeroshell architecture. MAD's lighter and simpler design is likely to bring the risk and cost associated with the mission down. Moreover, the lighter entry mass enables landing in the Martian highlands, at elevations inaccessible to current EDL technologies. This paper proposes a novel MAD concept for a Mars helicopter. We suggest a minimum science payload package to perform relevant science in the highlands. A variant of the Ingenuity helicopter is proposed to provide increased deceleration during MAD, and enough lift to fly the science payload in the highlands. We show in simulation that the lighter aeroshell results in a lower terminal velocity (30 m/s) at the end of the parachute phase of the EDL, and at higher altitudes than other approaches. After discussing the aerodynamics, controls, guidance, and mechanical challenges associated with deploying at such speed, we propose a backshell architecture that addresses them to release the helicopter in the safest conditions. Finally, we implemented the helicopter model and aerodynamic descent perturbations in the JPL Dynamics and Real-Time Simulation (DARTS)framework. Preliminary performance evaluation indicates landing and helicopter operations can be achieved up to +5 km MOLA (Mars Orbiter Laser Altimeter reference).", "date": "2020-11-16", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2020-4030", "id_number": "CaltechAUTHORS:20201106-131812557", "isbn": "9781624106088", "book_title": "ASCEND 2020", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201106-131812557", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech", "grant_number": "80NM0018D0004" }, { "agency": "JPL Research and Technology Development Fund" }, { "agency": "NASA Space Technology Research Fellowship", "grant_number": "80NSSC19K1152" } ] }, "other_numbering_system": { "items": [ { "id": "2020-4030", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2020-4030", "primary_object": { "basename": "2010.06630.pdf", "url": "https://authors.library.caltech.edu/records/93kdt-84m30/files/2010.06630.pdf" }, "pub_year": "2020", "author_list": "Delaune, Jeff; Izraelevitz, Jacob; et el." }, { "id": "https://authors.library.caltech.edu/records/79smy-ppv38", "eprint_id": 106433, "eprint_status": "archive", "datestamp": "2023-08-20 00:15:59", "lastmod": "2024-01-15 18:14:24", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lovinger-Zev", "name": { "family": "Lovinger", "given": "Zev" }, "orcid": "0000-0002-9313-9495" }, { "id": "Czarnota-C", "name": { "family": "Czarnota", "given": "Christophe" } }, { "id": "Ravindran-Suraj", "name": { "family": "Ravindran", "given": "Suraj" }, "orcid": "0000-0003-2930-7906" }, { "id": "Kettenbeil-C", "name": { "family": "Kettenbeil", "given": "Christian" } }, { "id": "Molinari-A", "name": { "family": "Molinari", "given": "Alain" } }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "G." }, "orcid": "0000-0002-2912-0001" } ] }, "title": "Shock structure and spall behavior of porous aluminum", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2020 Published by AIP Publishing. \n\nPublished Online: 04 November 2020. \n\nThe authors would like to acknowledge the work of Jacob Nuechterlein and Adam J. Polizzi from Elementum 3D for the design and manufacturing of the AM materials used in this work. The authors would like to thank Dr. Branden Kappes and Professor Aaron Stebner from the Colorado School of Mines for conducting micro-tomography on the porous samples.\n\nPublished - 12.0000913.pdf
", "abstract": "Porous materials under shock and impact loading present significant potential for energy absorption and shock mitigation in various applications. Furthermore, additively manufactured materials which feature inherent levels of porosity due to the manufacturing process are increasingly used in shock applications. In this work, we have investigated porous 6061 aluminum samples with different levels of porosity, which were manufactured using a modified process of 3D printing. To achieve pores smaller than the 3D printing resolution (<50 \u00b5m), the printing parameters were altered to control the pore sizes, resulting in porosities between 2%-10%. Plate impact experiments were conducted on these materials at pressures in the range of 2 to11 GPa, for which the free surface velocity was measured using a photonic Doppler velocimeter (PDV). The experiments were designed to extract both the shock structure properties and spall behavior. The structure of the steady shock was characterized as a function of porosity and shown to confirm trends revealed by the analytical approach (Czarnota et al, 2017), highlighting the importance of micro-inertia effects. The spall behavior was found to change significantly for the porous materials with respect to what was observed in dense materials. Mesoscale modeling has been carried out, to reveal the possible mechanisms underlying the observed phenomena.", "date": "2020-11-04", "date_type": "published", "publisher": "American Institute of Physics", "place_of_pub": "Melville, NY", "pagerange": "Art. No. 120015", "id_number": "CaltechAUTHORS:20201104-142330057", "isbn": "978-0-7354-4000-5", "book_title": "Shock Compression of Condensed Matter - 2019", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201104-142330057", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Lane-J-M-D", "name": { "family": "Lane", "given": "J. Matthew D." } }, { "id": "Germann-T-C", "name": { "family": "Germann", "given": "Timothy C." } }, { "id": "Armstrong-M-R", "name": { "family": "Armstrong", "given": "Michael R." } }, { "id": "Wixom-R", "name": { "family": "Wixom", "given": "Ryan" } }, { "id": "Damm-D", "name": { "family": "Damm", "given": "David" } }, { "id": "Zaug-J", "name": { "family": "Zaug", "given": "Joseph" } } ] }, "doi": "10.1063/12.0000913", "primary_object": { "basename": "12.0000913.pdf", "url": "https://authors.library.caltech.edu/records/79smy-ppv38/files/12.0000913.pdf" }, "pub_year": "2020", "author_list": "Lovinger, Zev; Czarnota, Christophe; et el." }, { "id": "https://authors.library.caltech.edu/records/910jq-nhd21", "eprint_id": 106474, "eprint_status": "archive", "datestamp": "2023-08-20 00:16:15", "lastmod": "2024-01-15 18:14:34", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kettenbeil-Christian", "name": { "family": "Kettenbeil", "given": "Christian" } }, { "id": "Lovinger-Zev", "name": { "family": "Lovinger", "given": "Zev" }, "orcid": "0000-0002-9313-9495" }, { "id": "Ravindran-Suraj", "name": { "family": "Ravindran", "given": "Suraj" }, "orcid": "0000-0003-2930-7906" }, { "id": "Mello-M", "name": { "family": "Mello", "given": "M." }, "orcid": "0000-0003-2129-9235" }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "G." }, "orcid": "0000-0002-2912-0001" } ] }, "title": "Pressure-shear plate impact experiments at very high pressures", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2020 Author(s). Published by AIP Publishing. \n\nPublished Online: 04 November 2020. \n\nThe authors are grateful for support from the Office of Naval Research (Award No. N00014-16-1-2839) for the\ndevelopment of the PSPI capability at high pressures and the Air Force Office of Scientific Research (Award No.\nFA955012-1-0091) for development of the PDV-HTV interferometer system. The PSPI work on magnesium was\nsupported by the Army Research Laboratory and was accomplished under Cooperative Agreement Number W911NF-12-2-0022.\n\nPublished - 12.0001099.pdf
", "abstract": "Recent modifications of a powder gun facility at Caltech have enabled pressure shear plate impact (PSPI) experiments on materials at very high strain rates (>10\u2077 s\u207b\u00b9) and pressures (>20\u2005GPa), that have not been reached before. The high strain rate/pressure regime expands significantly the advantages of this well-studied technique. However, it requires overcoming several challenges including requiring a new approach for analysis of the experimental measurements, to extract the material's strength. At high pressures, standard anvils such as steel and tungsten carbide (WC) do not remain elastic, and their inelastic behavior needs to be accounted for in the analysis. The methodology presented here extracts the strength of the material using a hybrid method, combining numerical simulations to simultaneously match both the normal and transverse free surface velocity measurements. First, the inelastic response of the anvils is measured using symmetric PSPI experiments and a material model is calibrated to best match the experimental measurements. Then, measuring the response including the material of interest in a sandwich PSPI configuration, the anvil's material model is used for the analysis and the extraction of the strength of the material of interest. The methodology is demonstrated for soda-lime glass with WC anvils and pure magnesium with steel anvils. The proposed methodology has the potential to expand the PSPI experiments to higher pressures and strain rates.", "date": "2020-11-04", "date_type": "published", "publisher": "American Institute of Physics", "place_of_pub": "Melville, NY", "pagerange": "Art. No. 120010", "id_number": "CaltechAUTHORS:20201106-094245803", "isbn": "978-0-7354-4000-5", "book_title": "Shock Compression of Condensed Matter - 2019", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201106-094245803", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-16-1-2839" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA955012-1-0091" }, { "agency": "Army Research Laboratory", "grant_number": "W911NF-12-2-0022" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Lane-J-Matthew-D", "name": { "family": "Lane", "given": "J. Matthew D." } }, { "id": "Germann-Timothy-C", "name": { "family": "Germann", "given": "Timothy C." } }, { "id": "Armstrong-Michael-R", "name": { "family": "Armstrong", "given": "Michael R." } }, { "id": "Wixom-Ryan", "name": { "family": "Wixom", "given": "Ryan" } }, { "id": "Damm-Dsvid", "name": { "family": "Damm", "given": "David" } }, { "id": "Zaug-Joseph", "name": { "family": "Zaug", "given": "Joseph" } } ] }, "doi": "10.1063/12.0001099", "primary_object": { "basename": "12.0001099.pdf", "url": "https://authors.library.caltech.edu/records/910jq-nhd21/files/12.0001099.pdf" }, "pub_year": "2020", "author_list": "Kettenbeil, Christian; Lovinger, Zev; et el." }, { "id": "https://authors.library.caltech.edu/records/qqajf-72b95", "eprint_id": 106473, "eprint_status": "archive", "datestamp": "2023-08-20 00:16:10", "lastmod": "2024-01-15 18:14:32", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ravindran-Suraj", "name": { "family": "Ravindran", "given": "Suraj" }, "orcid": "0000-0003-2930-7906" }, { "id": "Lovinger-Zev", "name": { "family": "Lovinger", "given": "Zev" }, "orcid": "0000-0002-9313-9495" }, { "id": "Kettenbeil-Christian", "name": { "family": "Kettenbeil", "given": "Christian" } }, { "id": "Mello-M", "name": { "family": "Mello", "given": "Michael" }, "orcid": "0000-0003-2129-9235" }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "Guruswami" }, "orcid": "0000-0002-2912-0001" } ] }, "title": "Pressure-shear plate impact experiments of magnesium at high pressures", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2020 Author(s). Published by AIP Publishing. \n\nPublished Online: 04 November 2020. \n\nThe PSPI work on magnesium was sponsored by the Army Research Laboratory and was accomplished under Cooperative Agreement Number W911NF-12-2-0022, which is gratefully acknowledged. Research was sponsored by the Army Research Laboratory and was accomplished under Cooperative Agreement Number W911NF-12-2-0022. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, of the Army Research Laboratory or the U.S. Government. The U.S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation herein.\n\nPublished - 12.0001022.pdf
", "abstract": "Magnesium and its alloys are widely used in the aerospace, automotive and defense industries, taking advantage of its high strength to weight ratio. However, these materials show strong anisotropy with its hexagonal close packed structure and texture. The experimental investigations probing the behavior of these materials at high pressures and strain rates are limited. In this study, experiments are conducted on extruded commercially pure magnesium using pressure shear plate impact (PSPI) experiments. The strength and the behavior of the materials are measured at pressures up to 10.5\u2005GPa and strain rates of 105 s\u22121. The PSPI experiments measure the materials under unique conditions, loading the material simultaneously in two directions. Experiments are conducted at two different pressures where the normal compressive stresses are aligned in one direction and the shear stresses, probing the material strength, are aligned perpendicular to the direction of the normal stress. The effect of pressure on the behavior of these materials under high pressures and strain rates are discussed. It was seen that magnesium exhibit higher strength at higher pressures due to the pressure hardening.", "date": "2020-11-04", "date_type": "published", "publisher": "American Institute of Physics", "place_of_pub": "Melville, NY", "pagerange": "Art. No. 120022", "id_number": "CaltechAUTHORS:20201106-093611155", "isbn": "978-0-7354-4000-5", "book_title": "Shock Compression of Condensed Matter - 2019", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201106-093611155", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Army Research Laboratory", "grant_number": "W911NF-12-2-0022" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Lane-J-Matthew-D", "name": { "family": "Lane", "given": "J. Matthew D." } }, { "id": "Germann-Timothy-C", "name": { "family": "Germann", "given": "Timothy C." } }, { "id": "Armstrong-Michael-R", "name": { "family": "Armstrong", "given": "Michael R." } }, { "id": "Wixom-Ryan", "name": { "family": "Wixom", "given": "Ryan" } }, { "id": "Damm-David", "name": { "family": "Damm", "given": "David" } }, { "id": "Zaug-Joseph", "name": { "family": "Zaug", "given": "Joseph" } } ] }, "doi": "10.1063/12.0001022", "primary_object": { "basename": "12.0001022.pdf", "url": "https://authors.library.caltech.edu/records/qqajf-72b95/files/12.0001022.pdf" }, "pub_year": "2020", "author_list": "Ravindran, Suraj; Lovinger, Zev; et el." }, { "id": "https://authors.library.caltech.edu/records/gce3p-skv36", "eprint_id": 104758, "eprint_status": "archive", "datestamp": "2023-08-19 23:34:52", "lastmod": "2023-10-20 20:48:41", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lee-Serin", "name": { "family": "Lee", "given": "Serin" } }, { "id": "Capuano-Vincenzo", "name": { "family": "Capuano", "given": "Vincenzo" }, "orcid": "0000-0002-6886-5719" }, { "id": "Harvard-Alexei", "name": { "family": "Harvard", "given": "Alexei" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Fast Uncertainty Estimation for Deep Learning Based Optical Flow", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2020 IEEE. \n\nThe authors thank A. Rahmani, A. Santamaria-Navarro, and F. Y. Hadaegh for their technical guidance.\n\nPublished - 09340963.pdf
Accepted Version - IROS_2020_optical_flow_new_uncertainty__4_.pdf
", "abstract": "We present a novel approach to reduce the processing time required to derive the estimation uncertainty map in deep learning-based optical flow determination methods. Without uncertainty aware reasoning, the optical flow model, especially when it is used for mission critical fields such as robotics and aerospace, can cause catastrophic failures. Although several approaches such as the ones based on Bayesian neural networks have been proposed to handle this issue, they are computationally expensive. Thus, to speed up the processing time, our approach applies a generative model, which is trained by input images and an uncertainty map derived through a Bayesian approach. By using synthetically generated images of spacecraft, we demonstrate that the trained generative model can produce the uncertainty map 100\u223c700 times faster than the conventional uncertainty estimation method used for training the generative model itself. We also show that the quality of uncertainty map derived by the generative model is close to that of the original uncertainty map. By applying the proposed approach, the deep learning model operated in real-time can avoid disastrous failures by considering the uncertainty as well as achieving better performance removing uncertain portions of the prediction result.", "date": "2020-10", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "10138-10144", "id_number": "CaltechAUTHORS:20200805-121745448", "isbn": "978-1-7281-6212-6", "book_title": "2020 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200805-121745448", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/IROS45743.2020.9340963", "primary_object": { "basename": "09340963.pdf", "url": "https://authors.library.caltech.edu/records/gce3p-skv36/files/09340963.pdf" }, "related_objects": [ { "basename": "IROS_2020_optical_flow_new_uncertainty__4_.pdf", "url": "https://authors.library.caltech.edu/records/gce3p-skv36/files/IROS_2020_optical_flow_new_uncertainty__4_.pdf" } ], "pub_year": "2020", "author_list": "Lee, Serin; Capuano, Vincenzo; et el." }, { "id": "https://authors.library.caltech.edu/records/fxatb-4nw10", "eprint_id": 99548, "eprint_status": "archive", "datestamp": "2023-08-19 22:35:41", "lastmod": "2023-10-18 18:33:04", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Shi-Guanya", "name": { "family": "Shi", "given": "Guanya" } }, { "id": "H\u00f6nig-W", "name": { "family": "H\u00f6nig", "given": "Wolfgang" } }, { "id": "Yue-Yisong", "name": { "family": "Yue", "given": "Yisong" }, "orcid": "0000-0001-9127-1989" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Neural-Swarm: Decentralized Close-Proximity Multirotor Control Using Learned Interactions", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2020 IEEE. \n\nWe thank Michael O'Connell and Xichen Shi for helpful discussions and Anya Vinogradsky for help with the firmware implementation. \n\nThe work is funded in part by Caltech's Center for Autonomous Systems and Technologies (CAST) and the Raytheon Company.\n\nSubmitted - 2003.02992.pdf
Submitted - ICRA_2020_Neural_Swarm.pdf
", "abstract": "In this paper, we present Neural-Swarm, a nonlinear decentralized stable controller for close-proximity flight of multirotor swarms. Close-proximity control is challenging due to the complex aerodynamic interaction effects between multirotors, such as downwash from higher vehicles to lower ones. Conventional methods often fail to properly capture these interaction effects, resulting in controllers that must maintain large safety distances between vehicles, and thus are not capable of close-proximity flight. Our approach combines a nominal dynamics model with a regularized permutation-invariant Deep Neural Network (DNN) that accurately learns the high-order multi-vehicle interactions. We design a stable nonlinear tracking controller using the learned model. Experimental results demonstrate that the proposed controller significantly outperforms a baseline nonlinear tracking controller with up to four times smaller worst-case height tracking errors. We also empirically demonstrate the ability of our learned model to generalize to larger swarm sizes.", "date": "2020-08", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "3241-3247", "id_number": "CaltechAUTHORS:20191029-155055963", "isbn": "978-1-7281-7395-5", "book_title": "2020 IEEE International Conference on Robotics and Automation (ICRA)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191029-155055963", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Center for Autonomous Systems and Technologies (CAST)" }, { "agency": "Raytheon Company" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Center-for-Autonomous-Systems-and-Technologies-(CAST)" } ] }, "doi": "10.1109/ICRA40945.2020.9196800", "primary_object": { "basename": "2003.02992.pdf", "url": "https://authors.library.caltech.edu/records/fxatb-4nw10/files/2003.02992.pdf" }, "related_objects": [ { "basename": "ICRA_2020_Neural_Swarm.pdf", "url": "https://authors.library.caltech.edu/records/fxatb-4nw10/files/ICRA_2020_Neural_Swarm.pdf" } ], "pub_year": "2020", "author_list": "Shi, Guanya; H\u00f6nig, Wolfgang; et el." }, { "id": "https://authors.library.caltech.edu/records/g2fbj-q8f51", "eprint_id": 105034, "eprint_status": "archive", "datestamp": "2023-08-19 22:41:02", "lastmod": "2023-10-20 21:17:47", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Finch-P-M", "name": { "family": "Finch", "given": "Peter M." } }, { "id": "Girard-J", "name": { "family": "Girard", "given": "Julian" } }, { "id": "Strand-C", "name": { "family": "Strand", "given": "Chris" } }, { "id": "Yu-Wesley", "name": { "family": "Yu", "given": "Wesley" } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "Joanna" }, "orcid": "0000-0003-3129-5035" }, { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "Hans" }, "orcid": "0000-0002-4903-8419" }, { "id": "Hanson-R", "name": { "family": "Hanson", "given": "Ronald" } } ] }, "title": "Measurements of Time-Resolved Air Freestream Nitric Oxide Rotational, Vibrational Temperature and Concentration in the T5 Reflected Shock Tunnel", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2020 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 17 Aug 2020.", "abstract": "We report on measurements of freestream temperature and nitric oxide (NO) collected in the Caltech T5 reflected shock tunnel facility. Quantum cascade lasers (QCL), emitting mid-infrared light resonant with fundamental rovibrational NO transitions, were directed through the supersonic (Mach ~5) flow immediately downstream of the nozzle exit plane. Tunable diode laser absorption spectroscopy (TDLAS) was used to measure the path-averaged rotational and vibrational temperature of NO in the flow, in addition to the NO partial pressure. The temperature measurements demonstrate strong evidence of NO rotational and vibrational equilibrium during the test-period (from 1 to 2 ms after shock reflection). Agreement between vibrational and rotational temperature was observed in all experiments, including one lower-enthalpy (h\u2080,\u221e \u2248 8 MJ/kg) and four higher-enthalpy (h\u2080,\u221e \u2248 18 MJ/kg) shots, during and after the nominal test time. Slight disagreement between the rotational and vibrational temperatures was observed during the start-up period preceding the test time. Unexpected absorption from CO and H\u2082O was also observed in the TDLAS measurements, yielding estimates of their partial pressures in the flow. The goal of these and future experiments is to help to inform improvements of existing models and solvers used for prediction of freestream conditions. Future efforts will include a more quantitative evaluation of freestream conditions, including core flow velocity and uniformity, and TDLAS measurements near relevant flow models.", "date": "2020-08", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2020-3714", "id_number": "CaltechAUTHORS:20200819-133135092", "isbn": "978-1-62410-602-6", "book_title": "AIAA Propulsion and Energy 2020 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200819-133135092", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2020-3714", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2020-3714", "pub_year": "2020", "author_list": "Finch, Peter M.; Girard, Julian; et el." }, { "id": "https://authors.library.caltech.edu/records/pqc5a-vn245", "eprint_id": 103475, "eprint_status": "archive", "datestamp": "2023-08-19 22:37:34", "lastmod": "2023-10-20 16:24:14", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Shi-Xichen", "name": { "family": "Shi", "given": "Xichen" } }, { "id": "Spieler-P", "name": { "family": "Spieler", "given": "Patrick" } }, { "id": "Tang-Ellande", "name": { "family": "Tang", "given": "Ellande" } }, { "id": "Lupu-E-S", "name": { "family": "Lupu", "given": "Elena-Sorina" }, "orcid": "0000-0002-3968-2630" }, { "id": "Tokumaru-Phillip", "name": { "family": "Tokumaru", "given": "Phillip" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Adaptive Nonlinear Control of Fixed-Wing VTOL with Airflow Vector Sensing", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2020 IEEE. \n\nThe authors thank M. Gharib for his technical guidance. This work is in part funded by AeroVironment, Inc.\n\nSubmitted - 2003.07558.pdf
", "abstract": "Fixed-wing vertical take-off and landing (VTOL) aircraft pose a unique control challenge that stems from complex aerodynamic interactions between wings and rotors. Thus, accurate estimation of external forces is indispensable for achieving high performance flight. In this paper, we present a composite adaptive nonlinear tracking controller for a fixed- wing VTOL. The method employs online adaptation of linear force models, and generates accurate estimation for wing and rotor forces in real-time based on information from a three-dimensional airflow sensor. The controller is implemented on a custom-built fixed-wing VTOL, which shows improved velocity tracking and force prediction during the transition stage from hover to forward flight, compared to baseline flight controllers.", "date": "2020-08", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "5321-5327", "id_number": "CaltechAUTHORS:20200526-151816924", "isbn": "978-1-7281-7395-5", "book_title": "2020 IEEE International Conference on Robotics and Automation (ICRA)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200526-151816924", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "AeroVironment" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/ICRA40945.2020.9197344", "primary_object": { "basename": "2003.07558.pdf", "url": "https://authors.library.caltech.edu/records/pqc5a-vn245/files/2003.07558.pdf" }, "pub_year": "2020", "author_list": "Shi, Xichen; Spieler, Patrick; et el." }, { "id": "https://authors.library.caltech.edu/records/m23p9-70z23", "eprint_id": 103797, "eprint_status": "archive", "datestamp": "2023-08-19 21:48:38", "lastmod": "2023-10-20 16:43:34", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Beyar-Michael", "name": { "family": "Beyar", "given": "Michael" } }, { "id": "Gea-Lie-Mine", "name": { "family": "Gea", "given": "Lie-Mine" } }, { "id": "Florence-T", "name": { "family": "Florence", "given": "Ted" } }, { "id": "Shmilovich-A", "name": { "family": "Shmilovich", "given": "Arvin" } }, { "id": "Jeon-David", "name": { "family": "Jeon", "given": "David" } }, { "id": "Hirsch-D", "name": { "family": "Hirsch", "given": "Damian" } }, { "id": "Rider-S", "name": { "family": "Rider", "given": "Stephanie" } }, { "id": "Oshima-Emile", "name": { "family": "Oshima", "given": "Emile" } }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "Morteza" }, "orcid": "0000-0003-0754-4193" }, { "id": "Khodadoust-A", "name": { "family": "Khodadoust", "given": "Abdollah" } } ] }, "title": "Progress on Experimental and Computational Investigation of Juncture Flows", "ispublished": "unpub", "full_text_status": "public", "keywords": "Applied Aerodynamics", "note": "\u00a9 2020 AIAA. \n\nPublished Online: 8 Jun 2020.", "abstract": "This paper describes a set of measurements taken at the Caltech Lucas Wind Tunnel, along with Computational Fluid Dynamic analyses, on a wing-body configuration. The configuration is designed to produce regions of separation in the juncture where the wing meets the body. Detailed near- and off-body stereo PIV measurements in the juncture flow are compared with predictions from computational methods based on the Reynolds Average Navier Stokes formulation. The results from the experimental measurements will become part of a database of high fidelity measurements, to be used for calibration of turbulence models and validation of emerging computational techniques.", "date": "2020-06-08", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2020-2734", "id_number": "CaltechAUTHORS:20200609-125716906", "isbn": "978-1-62410-598-2", "book_title": "AIAA Aviation 2020 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200609-125716906", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2020-2734", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2020-2734", "pub_year": "2020", "author_list": "Beyar, Michael; Gea, Lie-Mine; et el." }, { "id": "https://authors.library.caltech.edu/records/dg77g-4pr92", "eprint_id": 105174, "eprint_status": "archive", "datestamp": "2023-08-19 20:24:15", "lastmod": "2023-10-20 21:25:50", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bernhard-B", "name": { "family": "Bernhard", "given": "Benjamin" } }, { "id": "Choi-Changrak", "name": { "family": "Choi", "given": "Changrak" } }, { "id": "Rahmani-A", "name": { "family": "Rahmani", "given": "Amir" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Hadaegh-F-Y", "name": { "family": "Hadaegh", "given": "Fred" } } ] }, "title": "Coordinated Motion Planning for On-Orbit Satellite Inspection using a Swarm of Small-Spacecraft", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2020 IEEE. \n\nThis research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). We would like to thank Yashwanth Nakka and Wolfgang Hoenig for their valuable feedback on the work and also MichaelWolf for reviewing the manuscript. \u00a9 2019 California Institute of Technology. All rights reserved.\n\nPublished - 09172747.pdf
", "abstract": "This paper addresses the problem of how to plan optimal motion for a swarm of on-orbit servicing (OOS) small-spacecraft remotely inspecting a non-cooperative client spacecraft in Earth orbit. With the goal being to maximize the information gathered from the coordinated inspection, we present an integrated motion planning methodology that is a) fuel-efficient to ensure extended operation time and b) computationally-tractable to make possible on-board re-planning for improved exploration. Our method is decoupled into first offline selection of optimal orbits, followed by online coordinated attitude planning. In the orbit selection stage, we numerically evaluate the upper and lower bounds of the information gain for a discretized set of passive relative orbits (PRO). The algorithm then sequentially assigns orbits to each spacecraft using greedy heuristics. For the attitude planning stage, we propose a dynamic programming (DP) based attitude planner capable of addressing vehicle and sensor constraints such as attitude control system specifications, sensor field of view, sensing duration, and sensing angle. Finally, we validate the performance of the proposed algorithms through simulation of a design reference mission involving 3U CubeSats inspecting a satellite in low Earth orbit.", "date": "2020-03", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "1-13", "id_number": "CaltechAUTHORS:20200831-132647262", "isbn": "9781728127347", "book_title": "2020 IEEE Aerospace Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200831-132647262", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" }, { "agency": "NASA", "grant_number": "80NM0018D0004" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/aero47225.2020.9172747", "primary_object": { "basename": "09172747.pdf", "url": "https://authors.library.caltech.edu/records/dg77g-4pr92/files/09172747.pdf" }, "pub_year": "2020", "author_list": "Bernhard, Benjamin; Choi, Changrak; et el." }, { "id": "https://authors.library.caltech.edu/records/f5hyn-45830", "eprint_id": 100874, "eprint_status": "archive", "datestamp": "2023-08-19 19:40:04", "lastmod": "2024-01-14 22:05:30", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Heiden-Eric", "name": { "family": "Heiden", "given": "Eric" } }, { "id": "Pastor-Daniel", "name": { "family": "Pastor", "given": "Daniel" } }, { "id": "Vyshnav-Pradyumna", "name": { "family": "Vyshnav", "given": "Pradyumna" } }, { "id": "Agha-Mohammadi-A-A", "name": { "family": "Agha-Mohammadi", "given": "Ali-Akbar" }, "orcid": "0000-0001-5509-1841" } ] }, "title": "Heterogeneous Sensor Fusion via Confidence-Rich 3D Grid Mapping: Application to Physical Robots", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2020 Springer Nature Switzerland AG. \n\nFirst Online: 23 January 2020. \n\nThis research was carried out at the Jet Propulsion Laboratory under a contract with the National Aeronautics and Space Administration. U.S. Government sponsorship acknowledged.\n\nSupplemental Material - videodb_5501_77706_12336062_16x9_hq.mp4
", "abstract": "Autonomous navigation of intelligent physical systems largely depend on the ability of the system to generate an accurate map of its environment. Confidence-rich grid mapping algorithm provides a novel representation of the map based on range data by storing richer information at each voxel, including an estimate of the variance of occupancy. Capabilities and limitations are attributes of any given sensor, and therefore a single sensor may not be effective in providing detailed assessment of dynamic terrains. By incorporating multiple sensory modalities in a robot and extracting fused sensor information from them leads to higher certainty, noise reduction, and improved failure tolerance when mapping in real-world scenarios. In this work we investigate and evaluate sensor fusion techniques using confidence-rich grid mapping through a series of experiments on physical robotic systems with measurements from heterogeneous ranging sensors.", "date": "2020-01-23", "date_type": "published", "publisher": "Springer", "place_of_pub": "Cham", "pagerange": "725-736", "id_number": "CaltechAUTHORS:20200123-102509372", "isbn": "978-3-030-33949-4", "book_title": "Proceedings of the 2018 International Symposium on Experimental Robotics", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200123-102509372", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Xiao-Jing", "name": { "family": "Xiao", "given": "Jing" } }, { "id": "Kr\u00f6ger-T", "name": { "family": "Kr\u00f6ger", "given": "Torsten" } }, { "id": "Khatib-O", "name": { "family": "Khatib", "given": "Oussama" } } ] }, "doi": "10.1007/978-3-030-33950-0_62", "primary_object": { "basename": "videodb_5501_77706_12336062_16x9_hq.mp4", "url": "https://authors.library.caltech.edu/records/f5hyn-45830/files/videodb_5501_77706_12336062_16x9_hq.mp4" }, "pub_year": "2020", "author_list": "Heiden, Eric; Pastor, Daniel; et el." }, { "id": "https://authors.library.caltech.edu/records/9yhbt-01577", "eprint_id": 102209, "eprint_status": "archive", "datestamp": "2023-08-19 19:30:44", "lastmod": "2023-10-19 23:57:07", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Veismann-M", "name": { "family": "Veismann", "given": "Marcel" } }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "Morteza" }, "orcid": "0000-0003-0754-4193" } ] }, "title": "High Fidelity Aerodynamic Force Estimation for Multirotor Crafts in Free Flight", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2020 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 5 Jan 2020.", "abstract": "Aerodynamic investigation of multirotor crafts under non-hover conditions plays a vital role in the development of efficient and stable systems. Non-hover conditions include any flight scenario where the craft is no longer subject to to an infinite, stationary and undisturbed fluid. Examples of non-hover conditions are forward-flight, axial descent, and flying under ground effects. This paper presents the experimental framework for estimating multirotor free-flight forces. The presented method does not require rigid mounting of the craft to a load cell. Instead, the forces on the craft are estimated using two complementary methods-- one based on rigid body dynamics obtained by motion capture measurements and the other inferred from rotor rotational speed measurements. By considering these two independent estimates, with the dynamically-derived forces serving as a continuous reference, we are able to evaluate relative rotor performance, even under conditions where net forces on the craft are fluctuating. In order to map rotor rotational rates to rotor forces, we developed a closed-form expression which incorporates Reynolds number and rotor-rotor interaction effects. Using our free-flight force estimation technique, we accurately estimated rotor performance during various vertical flight conditions (i.e. ascent, descent, and hover with and without ground effects) with a high degree of accuracy.", "date": "2020-01-06", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2020-0303", "id_number": "CaltechAUTHORS:20200331-141548015", "isbn": "9781624105951", "book_title": "AIAA Scitech 2020 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200331-141548015", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2020-0303", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2020-0303", "pub_year": "2020", "author_list": "Veismann, Marcel and Gharib, Morteza" }, { "id": "https://authors.library.caltech.edu/records/hpt2x-a2g53", "eprint_id": 100651, "eprint_status": "archive", "datestamp": "2023-08-19 19:29:17", "lastmod": "2023-10-18 21:42:53", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ubamanyu-K", "name": { "family": "Ubamanyu", "given": "Kanthasamy" } }, { "id": "Hasanyan-A-D", "name": { "family": "Hasanyan", "given": "Armanj D." } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Experimental Study of Time-dependent Failure of High Strain Composites", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2020 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 5 Jan 2020.", "abstract": "High strain composites for coilable space structures can undergo micro-structural changes in the time period between stowage and deployment. These changes include the accumulation of residual stresses in response to curvature changes (stress-relaxation) and accumulation of damage, which may lead to rupture of high strain composites. Currently, the mechanisms that cause damage growth and failure are not well understood. In this study, new experimental approaches are explored for applying constant curvature changes, that replicate the stowage conditions while imaging the evaluation of cracks on the compression surface and of damage in the micro-structure of the test sample. The test temperature is raised to accelerate the failure process.", "date": "2020-01-05", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2020-0207", "id_number": "CaltechAUTHORS:20200110-160834737", "isbn": "978-1-62410-595-1", "book_title": "AIAA Scitech 2020 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200110-160834737", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2020-0207", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2020-0207", "pub_year": "2020", "author_list": "Ubamanyu, Kanthasamy; Hasanyan, Armanj D.; et el." }, { "id": "https://authors.library.caltech.edu/records/geyr4-fwg52", "eprint_id": 100663, "eprint_status": "archive", "datestamp": "2023-08-19 19:29:56", "lastmod": "2023-10-18 21:43:46", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Royer-F", "name": { "family": "Royer", "given": "Fabien" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Buckling of Ultralight Ladder-type Coilable Space Structures", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2020 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 5 Jan 2020.", "abstract": "We analyse the buckling and post-buckling behavior of ultralight ladder-type coilable structures for space solar power applications. The structures are composed of thin-shell longitudinal elements connected by thin rods, which can be flattened and packaged efficiently. Rather than relying on an eigenvalue based analysis, this paper presents an alternative approach to thin-shell buckling based on recent work on the stability of cylindrical and spherical shells. The stability of ladder-type structures loaded by normal pressure is studied using a probe that locally displaces the structure and a stability landscape for the structure is plotted. This landscape plot gives insight into the structure's buckling, post-buckling, and sensitivity to disturbances.", "date": "2020-01-05", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2020-1437", "id_number": "CaltechAUTHORS:20200113-083856811", "isbn": "978-1-62410-595-1", "book_title": "AIAA Scitech 2020 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200113-083856811", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2020-1437", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2020-1437", "pub_year": "2020", "author_list": "Royer, Fabien and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/xcxb2-wba52", "eprint_id": 100652, "eprint_status": "archive", "datestamp": "2023-08-19 19:29:21", "lastmod": "2023-10-18 21:42:55", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bae-Hyunji-Jane", "name": { "family": "Bae", "given": "Hyunji Jane" } }, { "id": "Dawson-S-T-M", "name": { "family": "Dawson", "given": "Scott T." }, "orcid": "0000-0002-0020-2097" }, { "id": "McKeon-B-J", "name": { "family": "McKeon", "given": "Beverley J." }, "orcid": "0000-0003-4220-1583" } ] }, "title": "Studying the effect of wall cooling in supersonic boundary layer flow using resolvent analysis", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2020 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 5 Jan 2020.", "abstract": "Analysis of the resolvent operator is used to study the properties of high-speed turbulent boundary layers for cooled walls. Previous study [1] shows that the resolvent response modes in the relatively subsonic region of high-speed turbulent boundary layers with adiabatic wall boundary conditions follow the same scaling law as those of the incompressible boundary layer case, validating Morkovin's hypothesis on a mode-by-mode basis. Here, we study the effect of the cooled-wall boundary condition on the individual resolvent response modes to understand the underlying mechanisms that cause the failure of Morkovin's hypothesis and velocity transformations for increasingly non-adiabatic walls. In particular, we show that the density and temperature resolvent mode shapes for the cooled-wall case exhibit a secondary peak in the inner and logarithmic layer, which is a result of the non-monotonic mean temperature profile that is absent in adiabatic cases. We also show that the secondary peak becomes more prominent with decreasing surface temperature ratio. The deviation of the mean velocity profiles is attributed to the change in the response modes in the near-wall region, the effect of which is propagated further away from the wall through nonlinear interactions.", "date": "2020-01-05", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2020-0575", "id_number": "CaltechAUTHORS:20200113-074130443", "isbn": "978-1-62410-595-1", "book_title": "AIAA Scitech 2020 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200113-074130443", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2020-0575", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2020-0575", "pub_year": "2020", "author_list": "Bae, Hyunji Jane; Dawson, Scott T.; et el." }, { "id": "https://authors.library.caltech.edu/records/fts5s-bpd55", "eprint_id": 100654, "eprint_status": "archive", "datestamp": "2023-08-19 19:29:24", "lastmod": "2023-10-18 21:43:19", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Pedivellano-A", "name": { "family": "Pedivellano", "given": "Antonio" } }, { "id": "Gdoutos-E-E", "name": { "family": "Gdoutos", "given": "Eleftherios" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Sequentially Controlled Dynamic Deployment of Ultra-Thin Shell Structures", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2020 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 5 Jan 2020.", "abstract": "This paper presents an approach to achieve the staged deployment of planar structures composed of multiple thin-shell elements. Releasable constraints are used to prescribe intermediate, known configurations along a strain energy-driven deployment path. An analytical model is derived to design the nominal deployment sequence of the structure by identifying kinematically compatible paths. Then, a finite element model is developed to capture the dynamic behavior of the shells during a staged deployment. Practical considerations, such as the deployment envelope and incorporation of the structure in a deployment mechanism are discussed. Finally, the proposed deployment sequence is demonstrated experimentally.", "date": "2020-01-05", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2020-0690", "id_number": "CaltechAUTHORS:20200113-075647741", "isbn": "978-1-62410-595-1", "book_title": "AIAA Scitech 2020 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200113-075647741", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2020-0690", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2020-0690", "pub_year": "2020", "author_list": "Pedivellano, Antonio; Gdoutos, Eleftherios; et el." }, { "id": "https://authors.library.caltech.edu/records/5vepc-c2j04", "eprint_id": 100655, "eprint_status": "archive", "datestamp": "2023-08-19 19:29:28", "lastmod": "2023-10-18 21:43:21", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Gdoutos-E-E", "name": { "family": "Gdoutos", "given": "Eleftherios" } }, { "id": "Truong-Alan", "name": { "family": "Truong", "given": "Alan" } }, { "id": "Pedivellano-A", "name": { "family": "Pedivellano", "given": "Antonio" } }, { "id": "Royer-F", "name": { "family": "Royer", "given": "Fabien" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Ultralight Deployable Space Structure Prototype", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2020 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 5 Jan 2020.", "abstract": "We present a lab demonstration of the packaging and deployment of an ultralight space structure prototype composed of thin shell longerons and battens. The prototype is integrated with a thin polyimide membrane which serves as mass representative of multi-functional elements that could be integrated into this type of deployable, such as integrated power collection and wireless transmission tiles for space solar power. A deployment mechanism using actively controlled pressure to package and deploy this structure ensuring its integrity is described. The deployable structure and deployment mechanism designs are scalable to 60 m X 60 m structures. The structure's mass scaling to larger sizes is described.", "date": "2020-01-05", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2020-0692", "id_number": "CaltechAUTHORS:20200113-080052698", "isbn": "978-1-62410-595-1", "book_title": "AIAA Scitech 2020 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200113-080052698", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2020-0692", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2020-0692", "pub_year": "2020", "author_list": "Gdoutos, Eleftherios; Truong, Alan; et el." }, { "id": "https://authors.library.caltech.edu/records/55594-4rr29", "eprint_id": 100664, "eprint_status": "archive", "datestamp": "2023-08-19 19:29:59", "lastmod": "2023-10-18 21:43:48", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Harvard-A", "name": { "family": "Harvard", "given": "Alexei" } }, { "id": "Capuano-V", "name": { "family": "Capuano", "given": "Vincenzo" }, "orcid": "0000-0002-6886-5719" }, { "id": "Shao-Eugene-Y", "name": { "family": "Shao", "given": "Eugene Y." } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Pose Estimation of Uncooperative Spacecraft from Monocular Images Using Neural Network Based Keypoints", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2020 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 5 Jan 2020.", "abstract": "A novel method for monocular-based pose estimation of uncooperative spacecraft using keypoints specialized for a given target is presented. A set of robust keypoints are created by examining the effectiveness of existing localization algorithms by simulating and testing different perspectives. The feature extraction and matching is used to build a model of the spacecraft before the flight mission using the same feature extraction algorithms that can be used during the mission. Further, a visibility map is determined for each keypoint to aid in outlier filtering, matching, and measurement covariance estimation. For initialization and matching, a Convolutional Neural Network (CNN) is trained to generate descriptors robust to illumination, scale, and affine changes for the pre-computed keypoints. In the second part of the paper, we focus on pose determination and filtering after keypoint-to-model matching. While several approaches for pose acquisition have been formulated, we propose a novel method for tracking that makes use of a nonlinear filter, based on the spacecraft translational and rotational relative dynamics which estimates the covariance of the vision-based observations using the keypoint preprocessing information. Further, the estimated propagated covariance for each extracted feature is used for aiding the feature matching.", "date": "2020-01-05", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2020-1874", "id_number": "CaltechAUTHORS:20200113-084156386", "isbn": "978-1-62410-595-1", "book_title": "AIAA Scitech 2020 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200113-084156386", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2020-1874", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2020-1874", "pub_year": "2020", "author_list": "Harvard, Alexei; Capuano, Vincenzo; et el." }, { "id": "https://authors.library.caltech.edu/records/jtmyz-fcp89", "eprint_id": 100666, "eprint_status": "archive", "datestamp": "2023-08-19 19:30:06", "lastmod": "2023-10-18 21:43:53", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Paranjape-A-A", "name": { "family": "Paranjape", "given": "Aditya A." }, "orcid": "0000-0002-3164-3215" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Hilton-H-H", "name": { "family": "Hilton", "given": "Harry H." } } ] }, "title": "Approximate Model for Cycle-Averaged Aerodynamic Forces, and its Application to Stability and Control of Bird-Scale Flapping-Wing Aircraft", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2020 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 5 Jan 2020.", "abstract": "We derive approximate, closed-form expressions for the cycle-averaged forces produced by flapping wings operating in a regime similar to birds and small unmanned aerial vehicles. The model is 2-D and intended mainly as an aid to performance and stability analysis, and control design. The model accounts for the nonlinear behavior of lift at high angles of attack, corrections for unsteadiness, as well as an elementary expression for drag. As an elementary application of the model, we determine the conditions under which the power consumption is minimized and those under which the range is maximized. We demonstrate how the model can be employed gainfully for stability analysis and control design.", "date": "2020-01-05", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2020-1963", "id_number": "CaltechAUTHORS:20200113-085148391", "isbn": "978-1-62410-595-1", "book_title": "AIAA Scitech 2020 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200113-085148391", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2020-1963", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2020-1963", "pub_year": "2020", "author_list": "Paranjape, Aditya A.; Chung, Soon-Jo; et el." }, { "id": "https://authors.library.caltech.edu/records/8s1mr-xk261", "eprint_id": 100656, "eprint_status": "archive", "datestamp": "2023-08-19 19:29:31", "lastmod": "2023-10-18 21:43:24", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hasanyan-A-D", "name": { "family": "Hasanyan", "given": "Armanj D." } }, { "id": "Leclerc-C", "name": { "family": "Leclerc", "given": "Christophe" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Interface Failure Analysis of Triangular Rollable and Collapsible (TRAC) Booms", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2020 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 5 Jan 2020.", "abstract": "Characterizing the interface bond of thin-ply composites is important for assessing the overall structural integrity. Due to the flexibility of thin composite laminates, it is not feasible to carry out mode I double cantilever beam (DCB) and mode II end notch flexure (ENF) tests, due to the large geometric changes undergone during testing. To reduce the compliance during testing, thick aluminum substrates are bonded to the two free-surfaces of the test laminates. DCB and ENF tests are specifically carried out in this configuration. A specific glass fiber plain weave interface of a 7-ply composite structure is tested. \u00b5CT imaging shows the presence of periodic voids of size scales of 200 \u00b5m, and local delaminated regions of 0 . 7 \u2212 5 . 6 mm. The former is attributed to capillary effects from the glass tows, while the latter is due to insufficient resin flow during the two-cure manufacturing process.", "date": "2020-01-05", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2020-0694", "id_number": "CaltechAUTHORS:20200113-081226991", "isbn": "978-1-62410-595-1", "book_title": "AIAA Scitech 2020 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200113-081226991", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2020-0694", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2020-0694", "pub_year": "2020", "author_list": "Hasanyan, Armanj D.; Leclerc, Christophe; et el." }, { "id": "https://authors.library.caltech.edu/records/1b77k-18j67", "eprint_id": 100659, "eprint_status": "archive", "datestamp": "2023-08-19 19:29:41", "lastmod": "2023-10-18 21:43:34", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Neet-M-C", "name": { "family": "Neet", "given": "Mallory C." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "Joanna M." }, "orcid": "0000-0003-3129-5035" } ] }, "title": "Effects of Surface Compliance on Shock Boundary Layer Interaction in the Caltech Mach 4 Ludwieg Tube", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2020 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 5 Jan 2020.", "abstract": "Understanding the effects of fluid-structure interactions caused by turbulent boundary layers and shock boundary layer interactions, on thin, compliant, structures is crucial for developing light-weight, reusable, high-speed vehicles. In this work, flow structures in a Mach 4 boundary layer are first studied over i) rigid flat plates to establish a baseline and ii) statically deformed geometries to investigate the flow response to surface deformation over longer time scales. Next, the flow response over a compliant steel panel under static and dynamic loading from an oscillating shock generator is investigated. Euler simulations are performed to design the geometry and location of the shock generator in the Caltech Mach 4 Ludwieg tube test section, predict the amplitude of the oscillation required to drive the pressure wave across the compliant surface, and to calculate the pressure rise on the compliant surface due to the dynamic load. Schlieren video, fast response pressure sensitive paint profiles, and laser displacement sensor measurements of the response of a 0.2 mm thick steel panel to loading from the shock generator are discussed and compared to similar measurements of the rigid case. The compliant panel center point deforms by nearly 4 panel thicknesses under these conditions and results in a flattened and elongated separation region at the interaction location and lower static pressure on the panel surface when compared to the rigid panel case.", "date": "2020-01-05", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2020-0816", "id_number": "CaltechAUTHORS:20200113-082409845", "isbn": "978-1-62410-595-1", "book_title": "AIAA Scitech 2020 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200113-082409845", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2020-0816", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2020-0816", "pub_year": "2020", "author_list": "Neet, Mallory C. and Austin, Joanna M." }, { "id": "https://authors.library.caltech.edu/records/7np70-7xp92", "eprint_id": 100658, "eprint_status": "archive", "datestamp": "2023-08-19 19:29:38", "lastmod": "2023-10-18 21:43:30", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lawson-J-M", "name": { "family": "Lawson", "given": "Joel M." }, "orcid": "0000-0002-3042-0909" }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "Joanna M." }, "orcid": "0000-0003-3129-5035" } ] }, "title": "Expansion Tube Freestream Disturbance Measurements using a Focused Laser Differential Interferometer", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2020 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 5 Jan 2020.", "abstract": "A focused laser differential interferometer (FLDI) is applied to Caltech's Hypervelocity Expansion Tube (HET). FLDI is shown to be sensitive enough to make high-bandwidth measurements of flow features at low-density conditions. The freestream disturbance level is quantified as a function of the sound speed ratio across the primary contact surface. This is done to experimentally investigate whether the freestream disturbances obey the acoustic wave theory proposed by Paull and Stalker. It is found that disturbance magnitudes generally decrease with reductions in this sound speed ratio, as predicted by the theory, but some anomalous results are observed that suggest additional controlling parameters beyond the acoustic model.", "date": "2020-01-05", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2020-1064", "id_number": "CaltechAUTHORS:20200113-082059519", "isbn": "978-1-62410-595-1", "book_title": "AIAA Scitech 2020 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200113-082059519", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2020-1064", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2020-1064", "pub_year": "2020", "author_list": "Lawson, Joel M. and Austin, Joanna M." }, { "id": "https://authors.library.caltech.edu/records/z9dpa-x7a96", "eprint_id": 98729, "eprint_status": "archive", "datestamp": "2023-08-19 18:54:13", "lastmod": "2023-10-18 17:36:03", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Nakka-Yashwanth-K", "name": { "family": "Nakka", "given": "Yashwanth Kumar" }, "orcid": "0000-0001-7897-3644" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Trajectory Optimization for Chance-Constrained Nonlinear Stochastic Systems", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2019 IEEE. \n\nThis work was in part funded by the Jet Propulsion Laboratory, California Institute of Technology and the Raytheon Company.\n\nAccepted Version - CDC19_1693_FI.pdf
", "abstract": "This paper presents a new method of computing a sub-optimal solution of a continuous-time continuous-space chance-constrained stochastic nonlinear optimal control problem (SNOC) problem. The proposed method involves two steps. The first step is to derive a deterministic nonlinear optimal control problem (DNOC) with convex constraints that are surrogate to the SNOC by using generalized polynomial chaos (gPC) expansion and tools taken from chance-constrained programming. The second step is to solve the DNOC problem using sequential convex programming (SCP) for trajectory generation. We prove that in the unconstrained case, the optimal value of the DNOC converges to that of SNOC asymptotically and that any feasible solution of the constrained DNOC is a feasible solution of the chance-constrained SNOC because the gPC approximation of the random variables converges to the true distribution. The effectiveness of the gPC-SCP method is demonstrated by computing safe trajectories for a second-order planar robot model with multiplicative stochastic uncertainty entering at the input while avoiding collisions with a specified probability.", "date": "2019-12", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "3811-3818", "id_number": "CaltechAUTHORS:20190918-132943526", "isbn": "978-1-7281-1398-2", "book_title": "2019 IEEE Conference on Decision and Control (CDC)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190918-132943526", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "JPL/Caltech" }, { "agency": "Raytheon Company" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Center-for-Autonomous-Systems-and-Technologies-(CAST)" } ] }, "doi": "10.1109/CDC40024.2019.9028893", "primary_object": { "basename": "CDC19_1693_FI.pdf", "url": "https://authors.library.caltech.edu/records/z9dpa-x7a96/files/CDC19_1693_FI.pdf" }, "pub_year": "2019", "author_list": "Nakka, Yashwanth Kumar and Chung, Soon-Jo" }, { "id": "https://authors.library.caltech.edu/records/9t7ka-qn467", "eprint_id": 104324, "eprint_status": "archive", "datestamp": "2023-08-19 18:59:36", "lastmod": "2023-10-20 19:18:15", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Cardona-Jennifer-L", "name": { "family": "Cardona", "given": "Jennifer L." } }, { "id": "Howland-Michael-F", "name": { "family": "Howland", "given": "Michael F." }, "orcid": "0000-0002-2878-3874" }, { "id": "Dabiri-J-O", "name": { "family": "Dabiri", "given": "John O." }, "orcid": "0000-0002-6722-9008" } ] }, "title": "Seeing the Wind: Visual Wind Speed Prediction with a Coupled Convolutional and Recurrent Neural Network", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2019 Neural Information Processing Systems Foundation, Inc.\n\nThe authors acknowledge Kelyn Wood, who assisted in setup for the wind tunnel test set. J.L.C. is funded through the Brit and Alex d'Arbeloff Stanford Graduate Fellowship, and M.F.H. is funded through a National Science Foundation Graduate Research Fellowship under Grant DGE-1656518 and a Stanford Graduate Fellowship.\n\nSubmitted - 1905.13290.pdf
Supplemental Material - 9078-seeing-the-wind-visual-wind-speed-prediction-with-a-coupled-convolutional-and-recurrent-neural-network-supplemental.zip
", "abstract": "Wind energy resource quantification, air pollution monitoring, and weather forecasting all rely on rapid, accurate measurement of local wind conditions. Visual observations of the effects of wind---the swaying of trees and flapping of flags, for example---encode information regarding local wind conditions that can potentially be leveraged for visual anemometry that is inexpensive and ubiquitous. Here, we demonstrate a coupled convolutional neural network and recurrent neural network architecture that extracts the wind speed encoded in visually recorded flow-structure interactions of a flag and tree in naturally occurring wind. Predictions for wind speeds ranging from 0.75-11 m/s showed agreement with measurements from a cup anemometer on site, with a root-mean-squared error approaching the natural wind speed variability due to atmospheric turbulence. Generalizability of the network was demonstrated by successful prediction of wind speed based on recordings of other flags in the field and in a controlled wind tunnel test. Furthermore, physics-based scaling of the flapping dynamics accurately predicts the dependence of the network performance on the video frame rate and duration.", "date": "2019-12", "date_type": "published", "publisher": "Neural Information Processing Systems Foundation, Inc.", "id_number": "CaltechAUTHORS:20200710-104503016", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200710-104503016", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Stanford University" }, { "agency": "NSF Graduate Research Fellowship", "grant_number": "DGE-1656518" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.48550/arXiv.1905.13290", "primary_object": { "basename": "1905.13290.pdf", "url": "https://authors.library.caltech.edu/records/9t7ka-qn467/files/1905.13290.pdf" }, "related_objects": [ { "basename": "9078-seeing-the-wind-visual-wind-speed-prediction-with-a-coupled-convolutional-and-recurrent-neural-network-supplemental.zip", "url": "https://authors.library.caltech.edu/records/9t7ka-qn467/files/9078-seeing-the-wind-visual-wind-speed-prediction-with-a-coupled-convolutional-and-recurrent-neural-network-supplemental.zip" }, { "basename": "9078-seeing-the-wind-visual-wind-speed-prediction-with-a-coupled-convolutional-and-recurrent-neural-network.pdf", "url": "https://authors.library.caltech.edu/records/9t7ka-qn467/files/9078-seeing-the-wind-visual-wind-speed-prediction-with-a-coupled-convolutional-and-recurrent-neural-network.pdf" } ], "pub_year": "2019", "author_list": "Cardona, Jennifer L.; Howland, Michael F.; et el." }, { "id": "https://authors.library.caltech.edu/records/wcpyf-xgq44", "eprint_id": 98728, "eprint_status": "archive", "datestamp": "2023-08-19 18:54:05", "lastmod": "2023-10-18 17:35:58", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Tsukamoto-Hiroyasu", "name": { "family": "Tsukamoto", "given": "Hiroyasu" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Convex Optimization-based Controller Design for Stochastic Nonlinear Systems using Contraction Analysis", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2019 IEEE. \n\nThis work was in part funded by the Jet Propulsion Laboratory, California Institute of Technology and Raytheon Company.\n\nAccepted Version - CDC19_1653_FI.pdf
", "abstract": "This paper presents an optimal feedback tracking controller for a class of It\u00f4 stochastic nonlinear systems, the design of which involves recasting a nonlinear system equation into a convex combination of multiple non-unique State-Dependent Coefficient (SDC) models. Its feedback gain and controller parameters are found by solving a convex optimization problem to minimize an upper bound of the steady-state tracking error. Multiple SDC parametrizations are utilized to provide a design flexibility to mitigate the effects of stochastic noise and to ensure that the system is controllable. Incremental stability of this controller is studied using stochastic contraction analysis and it is proven that the controlled trajectory exponentially converges to the desired trajectory with a non-vanishing error due to the linear matrix inequality state-dependent algebraic Riccati equation constraint. A discrete-time version of stochastic contraction analysis with respect to a state- and time-dependent metric is also presented in this paper. A simulation is performed to show the superiority of the proposed optimal feedback controller compared to a known exponentially-stabilizing nonlinear controller and a PID controller.", "date": "2019-12", "date_type": "published", "publisher": "IEEE", "id_number": "CaltechAUTHORS:20190918-132428278", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190918-132428278", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "JPL/Caltech" }, { "agency": "Raytheon Company" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Center-for-Autonomous-Systems-and-Technologies-(CAST)" } ] }, "doi": "10.1109/CDC40024.2019.9028942", "primary_object": { "basename": "CDC19_1653_FI.pdf", "url": "https://authors.library.caltech.edu/records/wcpyf-xgq44/files/CDC19_1653_FI.pdf" }, "pub_year": "2019", "author_list": "Tsukamoto, Hiroyasu and Chung, Soon-Jo" }, { "id": "https://authors.library.caltech.edu/records/jd307-18d93", "eprint_id": 98631, "eprint_status": "archive", "datestamp": "2023-08-19 17:48:33", "lastmod": "2024-01-14 21:57:06", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Breckinridge-J-B", "name": { "family": "Breckinridge", "given": "J. B." }, "orcid": "0000-0002-9488-098X" }, { "id": "Harvey-J-E", "name": { "family": "Harvey", "given": "J. E." } }, { "id": "Irvin-R-G", "name": { "family": "Irvin", "given": "R." } }, { "id": "Chipman-R-A", "name": { "family": "Chipman", "given": "R." } }, { "id": "Kupinski-M", "name": { "family": "Kupinski", "given": "M." } }, { "id": "Davis-Jeffrey", "name": { "family": "Davis", "given": "J." } }, { "id": "Kim-Dae-Wook", "name": { "family": "Kim", "given": "D. W." } }, { "id": "Ewan-D-S", "name": { "family": "Ewan", "given": "D." } }, { "id": "Lillie-C-F", "name": { "family": "Lillie", "given": "C. F." } }, { "id": "Hull-T-B", "name": { "family": "Hull", "given": "T." } } ] }, "title": "ExoPlanet Optics: conceptual design processes for stealth telescopes", "ispublished": "unpub", "full_text_status": "public", "keywords": "Terrestrial exoplanet imaging, HabEx, LUVOIR, space telescopes, coronagraphs, optical design, polarization, diffraction, mirror surface scatter", "note": "\u00a9 2019 Society of Photo-Optical Instrumentation Engineers (SPIE). \n\nThis work was funded in part by NASA research grant NNX17AB29G to James Breckinridge, PI, at the James C. Wyant College of Optical Sciences, University of Arizona, Tucson AZ. Additional support provided by: Caltech, and Photon Engineering, Tucson, AZ.\n\nPublished - 111150H.pdf
", "abstract": "In this paper we examine several contrast-degrading static signature sources present in current terrestrial exoplanet Lyot Coronagraph/Telescope optical systems. These are: - Unnecessary optical surfaces, which increase cost, absorption, scatter, wavefront control and alignment issues. A suggested solution is to make every effort to investigate innovative solutions to reduce the number of optical surfaces during the early design phase. Consider free-form optics. - Diffraction from secondary support systems and classical hexagon segmented apertures, which masks the low IWA terrestrial exoplanets. A suggested mitigation is to investigate curved secondary support systems and a pinwheel architecture for the deployable primary aperture. - Polarization Fresnel and form birefringence aberrations, which distort the system PSF, introduce absorption, scatter and wavefront control issues. Mitigation is to reduce all ray-angles of incidence to a minimum, investigate zero-loss polarization compensation wavefront technology, and investigate metal thin film deposition processes required to minimize form birefringence in large-area high-reflectivity coatings. - Small-angle specular or resolved angle scattered light, which places a narrow halo of incoherent light around the base of the PSF. There is no requirement on mirror smooth-surface scatter. Investigate the physical source of the small angle scatter and develop mirror polishing and thin film deposition processes to minimize scatter.", "date": "2019-09-09", "date_type": "published", "publisher": "Society of Photo-Optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "Art. No. 111150H", "id_number": "CaltechAUTHORS:20190913-081328146", "isbn": "9781510629233", "book_title": "UV/Optical/IR Space Telescopes and Instruments: Innovative Technologies and Concepts IX", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190913-081328146", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA", "grant_number": "NNX17AB29G" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Barto-A-A", "name": { "family": "Barto", "given": "Allison A." } }, { "id": "Breckinridge-J-B", "name": { "family": "Breckinridge", "given": "James B." } }, { "id": "Stahl-H-P", "name": { "family": "Stahl", "given": "H. Philip" } } ] }, "doi": "10.1117/12.2528825", "primary_object": { "basename": "111150H.pdf", "url": "https://authors.library.caltech.edu/records/jd307-18d93/files/111150H.pdf" }, "pub_year": "2019", "author_list": "Breckinridge, J. B.; Harvey, J. E.; et el." }, { "id": "https://authors.library.caltech.edu/records/9es63-xhk04", "eprint_id": 95012, "eprint_status": "archive", "datestamp": "2023-08-19 16:27:33", "lastmod": "2023-10-20 18:29:19", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Cai-Karena-X", "name": { "family": "Cai", "given": "Karena X." } }, { "id": "Harvard-A", "name": { "family": "Harvard", "given": "Alexei" } }, { "id": "Murray-R-M", "name": { "family": "Murray", "given": "Richard M." }, "orcid": "0000-0002-5785-7481" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Robust Estimation Framework with Semantic Measurements", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2019 AACC. \n\nThis work was in part supported by AeroVironment, Inc., Boeing, and Caltech's Center for Autonomous Systems and Technologies (CAST). \n\nThe authors would like to acknowledge Andrew Stuart for helpful conversations on data assimilation methods for this paper.\n\nPublished - 08814793.pdf
Submitted - ACC19_1030_FI.pdf
", "abstract": "Conventional simultaneous localization and mapping (SLAM) algorithms rely on geometric measurements and require loop-closure detections to correct for drift accumulated over a vehicle trajectory. Semantic measurements can add measurement redundancy and provide an alternative form of loop closure. We propose two different estimation algorithms that incorporate semantic measurements provided by vision-based object classifiers. An a priori map of regions where the objects can be detected is assumed. The first estimation framework is posed as a maximum-likelihood problem, where the likelihood function for semantic measurements is derived from the confusion matrices of the object classifiers. The second estimation framework is comprised of two parts: 1) a continuous-state estimation formulation that includes semantic measurements as a form of state constraints and 2) a discrete-state estimation formulation used to compute the certainty of object detection measurements using a Hidden Markov Model (HMM). The advantages of incorporating semantic measurements in these frameworks are demonstrated in numerical simulations. In particular, the proposed estimation algorithms improve upon the robustness and accuracy of conventional SLAM algorithms.", "date": "2019-07", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "3809-3816", "id_number": "CaltechAUTHORS:20190426-090024789", "isbn": "978-1-5386-7926-5", "book_title": "2019 American Control Conference (ACC)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190426-090024789", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "AeroVironment" }, { "agency": "Boeing Corporation" }, { "agency": "Center for Autonomous Systems and Technologies" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Center-for-Autonomous-Systems-and-Technologies-(CAST)" } ] }, "doi": "10.23919/ACC.2019.8814793", "primary_object": { "basename": "08814793.pdf", "url": "https://authors.library.caltech.edu/records/9es63-xhk04/files/08814793.pdf" }, "related_objects": [ { "basename": "ACC19_1030_FI.pdf", "url": "https://authors.library.caltech.edu/records/9es63-xhk04/files/ACC19_1030_FI.pdf" } ], "pub_year": "2019", "author_list": "Cai, Karena X.; Harvard, Alexei; et el." }, { "id": "https://authors.library.caltech.edu/records/rg4sd-n6h15", "eprint_id": 92658, "eprint_status": "archive", "datestamp": "2023-08-19 15:34:02", "lastmod": "2023-10-20 15:57:10", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Shi-Guanya", "name": { "family": "Shi", "given": "Guanya" }, "orcid": "0000-0002-9075-3705" }, { "id": "Shi-Xichen", "name": { "family": "Shi", "given": "Xichen" }, "orcid": "0000-0002-5366-9256" }, { "id": "O'Connell-Michael", "name": { "family": "O'Connell", "given": "Michael" } }, { "id": "Yu-Rose", "name": { "family": "Yu", "given": "Rose" }, "orcid": "0000-0002-8491-7937" }, { "id": "Azizzadenesheli-Kamyar", "name": { "family": "Azizzadenesheli", "given": "Kamyar" }, "orcid": "0000-0001-8507-1868" }, { "id": "Anandkumar-A", "name": { "family": "Anandkumar", "given": "Animashree" }, "orcid": "0000-0002-6974-6797" }, { "id": "Yue-Yisong", "name": { "family": "Yue", "given": "Yisong" }, "orcid": "0000-0001-9127-1989" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Neural Lander: Stable Drone Landing Control using Learned Dynamics", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2019 IEEE. \n\nThe authors thank Joel Burdick, Mory Gharib and Daniel Pastor Moreno. The work is funded in part by Caltech's Center for Autonomous Systems and Technologies and Raytheon Company.\n\nSubmitted - 1811.08027.pdf
", "abstract": "Precise near-ground trajectory control is difficult for multi-rotor drones, due to the complex aerodynamic effects caused by interactions between multi-rotor airflow and the environment. Conventional control methods often fail to properly account for these complex effects and fall short in accomplishing smooth landing. In this paper, we present a novel deep-learning-based robust nonlinear controller (Neural-Lander) that improves control performance of a quadrotor during landing. Our approach combines a nominal dynamics model with a Deep Neural Network (DNN) that learns high-order interactions. We apply spectral normalization (SN) to constrain the Lipschitz constant of the DNN. Leveraging this Lipschitz property, we design a nonlinear feedback linearization controller using the learned model and prove system stability with disturbance rejection. To the best of our knowledge, this is the first DNN-based nonlinear feedback controller with stability guarantees that can utilize arbitrarily large neural nets. Experimental results demonstrate that the proposed controller significantly outperforms a Baseline Nonlinear Tracking Controller in both landing and cross-table trajectory tracking cases. We also empirically show that the DNN generalizes well to unseen data outside the training domain.", "date": "2019-05", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "9784-9790", "id_number": "CaltechAUTHORS:20190205-100744248", "isbn": "978-1-5386-6027-0", "book_title": "2019 International Conference on Robotics and Automation (ICRA)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190205-100744248", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Center for Autonomous Systems and Technologies" }, { "agency": "Raytheon Company" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Center-for-Autonomous-Systems-and-Technologies-(CAST)" } ] }, "doi": "10.1109/ICRA.2019.8794351", "primary_object": { "basename": "1811.08027.pdf", "url": "https://authors.library.caltech.edu/records/rg4sd-n6h15/files/1811.08027.pdf" }, "pub_year": "2019", "author_list": "Shi, Guanya; Shi, Xichen; et el." }, { "id": "https://authors.library.caltech.edu/records/g48zt-fej12", "eprint_id": 97042, "eprint_status": "archive", "datestamp": "2023-08-19 14:38:40", "lastmod": "2023-10-20 21:52:34", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Wallace-J-K", "name": { "family": "Wallace", "given": "J. Kent" } }, { "id": "Serabyn-E", "name": { "family": "Serabyn", "given": "Eugene" } }, { "id": "Lindensmith-C-A", "name": { "family": "Lindensmith", "given": "Chris" } }, { "id": "Nadeau-J-L", "name": { "family": "Nadeau", "given": "Jay" }, "orcid": "0000-0001-5258-0076" }, { "id": "Rider-S", "name": { "family": "Rider", "given": "Stephanie" } }, { "id": "Bedrossian-M", "name": { "family": "Bedrossian", "given": "Manuel" } } ] }, "title": "A multiwavelength digital holographic microscope architecture for enhancing life detection", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2019 IEEE. \n\nThis work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.", "abstract": "Spectral properties of living organism can provide a discriminating method for characterization. However, digital holographic microscopy (DHM), a high-resolution, volumetric imaging technique that is well-suited for examining microbial species is typically monochromatic. Thus, the spectral properties of bacteria are not probed with DHM save only for the wavelength of operation. Here we describe a new DHM instrument which enhances the method via the simultaneous recording of wavelength multiplexed holograms of the sample. This coarse spectral encoding is akin to labeling with RGB values, thereby producing colorized images of the species which enables a new dimension of characterization. This new instrument is derived from a previous architecture which has already demonstrated superior opto/mechanical stability. Herein, this novel instrument is described, and the results of experimental measurements taken with this new instrument are shown.", "date": "2019-03", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "1-6", "id_number": "CaltechAUTHORS:20190710-155312746", "isbn": "9781538668542", "book_title": "2019 IEEE Aerospace Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190710-155312746", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/AERO.2019.8742091", "pub_year": "2019", "author_list": "Wallace, J. Kent; Serabyn, Eugene; et el." }, { "id": "https://authors.library.caltech.edu/records/yt682-anp50", "eprint_id": 97653, "eprint_status": "archive", "datestamp": "2023-08-19 13:48:49", "lastmod": "2023-10-18 16:10:52", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Jeon-David", "name": { "family": "Jeon", "given": "David" } }, { "id": "Beyar-Michael", "name": { "family": "Beyar", "given": "Michael" } }, { "id": "Gea-Lie-Mine", "name": { "family": "Gea", "given": "Lie-Mine" } }, { "id": "Hirsch-D", "name": { "family": "Hirsch", "given": "Damian" } }, { "id": "Rider-S", "name": { "family": "Rider", "given": "Stephanie" } }, { "id": "Willert-C", "name": { "family": "Willert", "given": "Christian" }, "orcid": "0000-0002-1668-0181" }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "Morteza" }, "orcid": "0000-0003-0754-4193" }, { "id": "Khodadoust-A", "name": { "family": "Khodadoust", "given": "Abdollah" } } ] }, "title": "Progress on Experimental and Computational Investigation of Juncture Flows", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2019 American Institute of Aeronautics and Astronautics.", "abstract": "This paper describes a set of measurements taken at the Caltech Lucas Wind Tunnel, along with Computational Fluid Dynamic analyses, on a wing-body configuration. The configuration is designed to produce regions of separation in the juncture where the wing meets the body. Detailed on- and off-body measurements in the juncture flow are compared with RANS predictions. The results from the experimental measurements will become part of a database of high fidelity measurements, to be used for calibration of turbulence models and validation of emerging computational prediction techniques.", "date": "2019-01-07", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2019-0081", "id_number": "CaltechAUTHORS:20190805-134838483", "isbn": "9781624105784", "book_title": "AIAA Scitech 2019 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190805-134838483", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2019-0081", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2019-0081", "pub_year": "2019", "author_list": "Jeon, David; Beyar, Michael; et el." }, { "id": "https://authors.library.caltech.edu/records/xevy8-dkx71", "eprint_id": 97645, "eprint_status": "archive", "datestamp": "2023-08-19 13:48:26", "lastmod": "2023-10-18 16:10:30", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Dawson-S-T-M", "name": { "family": "Dawson", "given": "Scott T. M." }, "orcid": "0000-0002-0020-2097" }, { "id": "McKeon-B-J", "name": { "family": "McKeon", "given": "Beverley J." }, "orcid": "0000-0003-4220-1583" } ] }, "title": "Studying the Effects of Compressibility in Planar Couette Flow using Resolvent Analysis", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2019 American Institute of Aeronautics and Astronautics.", "abstract": "Analysis of the resolvent operator is used to study the properties of compressible planar Couette flow. In particular, we study how changing the Mach number affects the shape and amplitude of responses to optimal disturbances across a range of spatial and temporal frequencies. We consider Mach numbers up to 5, and show that the dependence of the resolvent norm(leading singular value) on streamwise and spanwise wavenumbers follows similar trends to the incompressible case, with the amplitude of the resolvent norm typically decreasing with increasing Mach number. An exception to this occurs when acoustic eigenmodes (which are not present in the incompressible regime) have eigenvalues sufficiently close to the temporal frequency \u03c9 such that modal resonance with this mode is the dominant contributor to the resolvent gain. This occurs, for example, for streamwise-constant disturbances for sufficiently low spanwise wavenumber. In addition, the resolvent formulation of the governing equations allows us to study independently the effects due to an altered mean/equilibrium profile due to compressibility, and the effects due to the changing linearized Navier-Stokes equations. This approach provides a framework for the study of compressible turbulent wall-bounded flows.", "date": "2019-01-07", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2019-2139", "id_number": "CaltechAUTHORS:20190805-134837522", "isbn": "9781624105784", "book_title": "AIAA Scitech 2019 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190805-134837522", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2019-2139", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2019-2139", "pub_year": "2019", "author_list": "Dawson, Scott T. M. and McKeon, Beverley J." }, { "id": "https://authors.library.caltech.edu/records/xp6my-3s779", "eprint_id": 97652, "eprint_status": "archive", "datestamp": "2023-08-19 13:48:46", "lastmod": "2023-10-18 16:10:49", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Yanes-N-J", "name": { "family": "Yanes", "given": "Nelson J." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "Joanna M." }, "orcid": "0000-0003-3129-5035" } ] }, "title": "Nitric Oxide Spectroscopic Measurements in a Hypervelocity Stagnation Flow", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2019 American Institute of Aeronautics and Astronautics.", "abstract": "Spatially resolved emission spectra are collected along the stagnation streamline of hypervelocity flow over a circular cylinder. Excitation temperatures are extracted from the NO \u03b3 band (A^2\u03a3^+ - \u03a7^2\u03a0) emission at downstream locations behind the bow shock. The result is a temperature relaxation profile that quantifies the state of thermal non-equilibrium. Results are compared against a zero-dimensional state-to-state model and a two-temperature, reacting Navier-Stokes simulation. Test gas O_2 mole fraction is varied from 30% to 120% of the air value to examine changes in relaxation profile.", "date": "2019-01-07", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2019-0794", "id_number": "CaltechAUTHORS:20190805-134838397", "isbn": "9781624105784", "book_title": "AIAA Scitech 2019 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190805-134838397", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2019-0794", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2019-0794", "pub_year": "2019", "author_list": "Yanes, Nelson J. and Austin, Joanna M." }, { "id": "https://authors.library.caltech.edu/records/1bjjh-21f55", "eprint_id": 104777, "eprint_status": "archive", "datestamp": "2023-08-19 13:49:00", "lastmod": "2023-10-20 20:50:19", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lawson-Joel-M", "name": { "family": "Lawson", "given": "Joel M." }, "orcid": "0000-0002-3042-0909" }, { "id": "Neet-Mallory-C", "name": { "family": "Neet", "given": "Mallory C." } }, { "id": "Grossman-Ilan-J", "name": { "family": "Grossman", "given": "Ilan J." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "Joanna M." }, "orcid": "0000-0003-3129-5035" } ] }, "title": "Characterization of a Focused Laser Differential Interferometer", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2019 American Institute of Aeronautics and Astronautics. \nPublished by the American Institute of Aeronautics and Astronautics, Inc. \n\nPublished Online: 6 Jan 2019. \n\nThe authors would like to gratefully acknowledge Prof. J. E. Shepherd for all his guidance and interest in this project,\nas well as providing the laboratory space to perform the experimental work. This work was partially supported by the\nOffice of Naval Research award N00014-16-1-2503 with Dr. Eric Marineau and the Air Force Research Laboratory\naward STTR FA8651-17-C-0071 with Dr. Daniel Reasor.\n\nPublished - 541450.pdf
", "abstract": "A focused laser differential interferometer (FLDI) has been experimentally characterized. The static response was probed using a steady, laminar helium jet, and the dynamic response was investigated using a free ultrasonic acoustic beam. In the case of the jet, the refractive index field was independently measured using a Mach-Zehnder interferometer operating simultaneously alongside FLDI. The experimental data were compared with numerical simulations of the FLDI response based on geometric optics and a ray-tracing algorithm. Close quantitative agreement was found between data and simulation results, validating this approach to modeling FLDI performance. Emphasis was given to quantification of the spatial sensitivity of the system, a key characteristic of FLDI, especially when applied to hypersonic ground testing facilities where strong turbulent flow exists outside the core flow.", "date": "2019-01-07", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2019-2296", "id_number": "CaltechAUTHORS:20200806-124527212", "isbn": "978-1-62410-578-4", "book_title": "AIAA Scitech 2019 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200806-124527212", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-16-1-2503" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA8651-17-C-0071" } ] }, "other_numbering_system": { "items": [ { "id": "2019-2296", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2019-2296", "primary_object": { "basename": "541450.pdf", "url": "https://authors.library.caltech.edu/records/1bjjh-21f55/files/541450.pdf" }, "pub_year": "2019", "author_list": "Lawson, Joel M.; Neet, Mallory C.; et el." }, { "id": "https://authors.library.caltech.edu/records/p3s81-12k79", "eprint_id": 97648, "eprint_status": "archive", "datestamp": "2023-08-19 13:48:36", "lastmod": "2023-10-18 16:10:40", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Leibowitz-M-G", "name": { "family": "Leibowitz", "given": "Matthew G." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "Joanna M." }, "orcid": "0000-0003-3129-5035" } ] }, "title": "Hypervelocity Measurements of Mid-Wave Infrared CO_2 Radiation Impinging on Blunt Bodies", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2019 American Institute of Aeronautics and Astronautics.", "abstract": "We present measurements of blunt body mid-wave infrared CO_2 radiation obtained in the Hypervelocity Expansion Tube at velocities between 3.1 and 3.4 km/s and freestream densities between 8 and 15 g/m^3 as well as shock tube measurements at velocities between 1 and 2 km/s and freestream densities between 70 and 1900 g/m^3. Point measurements of radiation collected using fiber optics embedded at the 0 and 16 degree angle of attack stagnation point of a scaled Mars Science Laboratory heat shield geometry are made. Spectrally resolved results over wavelengths of 4000-5300 nm are directly compared to numerical simulations using the NASA Langley LAURA CFD and HARA radiation codes.", "date": "2019-01-07", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2019-1555", "id_number": "CaltechAUTHORS:20190805-134838013", "isbn": "9781624105784", "book_title": "AIAA Scitech 2019 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190805-134838013", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2019-1555", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2019-1555", "pub_year": "2019", "author_list": "Leibowitz, Matthew G. and Austin, Joanna M." }, { "id": "https://authors.library.caltech.edu/records/s9mmb-pby41", "eprint_id": 97649, "eprint_status": "archive", "datestamp": "2023-08-19 13:48:39", "lastmod": "2023-10-18 16:10:43", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Pedivellano-A", "name": { "family": "Pedivellano", "given": "Antonio" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Stability Analysis of Coiled Tape Springs", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2019 American Institute of Aeronautics and Astronautics.", "abstract": "Tape springs have been used for many years in deployable booms and space mechanisms and currently are bing considered as components for more advanced deployable structures. Tape springs can be elastically coiled and will self-deploy when released. Their stability in the packaged configuration is critical for these applications. We propose a numerical and analytical framework to investigate the stability of coiled isotropic tape springs, where neither tension nor radial pressure are applied. Torsional and bending instabilities were observed when the ration between the coiled radius and the radius of the cross-section exceeded a critical value. A stability boundary is derived for different geometries and material properties. The effects of varying the number of coils and the self-contact conditions between adjacent loops of a tape spring are also studied, and the existence of out-of-plane instability modes is discussed.", "date": "2019-01-07", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2019-1523", "id_number": "CaltechAUTHORS:20190805-134838114", "isbn": "9781624105784", "book_title": "AIAA Scitech 2019 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190805-134838114", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2019-1523", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2019-1523", "pub_year": "2019", "author_list": "Pedivellano, Antonio and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/7v31v-s0k51", "eprint_id": 97656, "eprint_status": "archive", "datestamp": "2023-08-19 13:48:55", "lastmod": "2023-10-18 16:11:01", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "T\u00fcrk-D-A", "name": { "family": "T\u00fcrk", "given": "Daniel-Alexander" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Parametric Design of Conforming Joints for Thin-Shell Coilable Structures", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2019 American Institute of Aeronautics and Astronautics.", "abstract": "This paper addresses the problem of designing and building structural connections (joints) for ultra-thin shells employed in large coilable structures for space applications. A conforming joint design concept for ladder-type coilable thin shells is proposed. A parametric design tool was developed to study the geometry of two joints that become overlapped in the coiled configuration as a function of the coiling radius and joint radii. Parametric design results are validated through finite element simulations. The proposed design tool provides a high level of design flexibility and is of interest in the spacecraft design process making use of ultra-thin shells.", "date": "2019-01-07", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2019-1259", "id_number": "CaltechAUTHORS:20190805-134838792", "isbn": "9781624105784", "book_title": "AIAA Scitech 2019 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190805-134838792", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2019-1259", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2019-1259", "pub_year": "2019", "author_list": "T\u00fcrk, Daniel-Alexander and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/cab99-hgm06", "eprint_id": 97647, "eprint_status": "archive", "datestamp": "2023-08-19 13:48:33", "lastmod": "2023-10-18 16:10:36", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Gdoutos-E-E", "name": { "family": "Gdoutos", "given": "Eleftherios E." } }, { "id": "Leclerc-C", "name": { "family": "Leclerc", "given": "Christophe" } }, { "id": "Royer-F", "name": { "family": "Royer", "given": "Fabien" } }, { "id": "T\u00fcrk-D-A", "name": { "family": "T\u00fcrk", "given": "Daniel-Alexander" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Ultralight Spacecraft Structure Prototype", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2019 American Institute of Aeronautics and Astronautics.", "abstract": "We demonstrate the development of a lightweight 1.7 m X 1.7 m prototype spacecraft structure with areal density of 150 g/m^2. The structure is composed of individual ladder-type components that can be used to support flexible multi0-functional elements such as integrated power collection and wireless transmission tiles used for space solar power. This spacecraft structure design is scalable up to 60 m X 60 m. The structural design, ultra-light component manufacture and, prototype assembly are demonstrated. Shape accuracy within 0.5\u00b0 from nominal is achieved and outlook for further mass reduction is described.", "date": "2019-01-07", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2019-1749", "id_number": "CaltechAUTHORS:20190805-134837694", "isbn": "9781624105784", "book_title": "AIAA Scitech 2019 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190805-134837694", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2019-1749", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2019-1749", "pub_year": "2019", "author_list": "Gdoutos, Eleftherios E.; Leclerc, Christophe; et el." }, { "id": "https://authors.library.caltech.edu/records/xzqen-ada85", "eprint_id": 97655, "eprint_status": "archive", "datestamp": "2023-08-19 13:48:52", "lastmod": "2023-10-18 16:10:58", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Leclerc-C", "name": { "family": "Leclerc", "given": "Christophe" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Reducing Stress Concentration in the Transition Region of Coilable Ultra-Thin-Shell Booms", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2019 American Institute of Aeronautics and Astronautics.", "abstract": "High stress concentrations leading to material failure have been observed in TRAC booms coiled under tension around a circular hub. The stress concentrations are typically observed in the transition region between the fully deployed and coiled sections of the boom. A numerical simulation framework is proposed to model the coiling process analyses the stress distribution in the transition region. Isotropic booms are first studied to understand the effects of the cross-section geometry and the boundary conditions during coiling. Compressive stress is reduced by 13% and 26% by using a variable curvature cross-section and adding nip rollers in the coiling mechanism respectively. For an ultra-thin glass fiber-carbon fiber composite laminate, the compressive stress is similarly reduced by 24% and 11%. The variable curvature cross-section is shown to eliminate the stress concentration in the transition region.", "date": "2019-01-07", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2019-1522", "id_number": "CaltechAUTHORS:20190805-134838677", "isbn": "9781624105784", "book_title": "AIAA Scitech 2019 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190805-134838677", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2019-1522", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2019-1522", "pub_year": "2019", "author_list": "Leclerc, Christophe and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/ycnca-90x66", "eprint_id": 99816, "eprint_status": "archive", "datestamp": "2023-08-19 13:47:39", "lastmod": "2023-10-18 18:50:03", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Arya-M", "name": { "family": "Arya", "given": "Manan" } }, { "id": "Sauder-J-F", "name": { "family": "Sauder", "given": "Jonathan" } }, { "id": "Hodges-R-E", "name": { "family": "Hodges", "given": "Richard E." }, "orcid": "0000-0002-1132-0259" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Large-Area Deployable Reflectarray Antenna for CubeSats", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2019 by the American Institute of Aeronautics and Astronautics, Inc. The U.S. Government has a royalty-free license to exercise all rights under the copyright claimed herein for Governmental purposes. All other rights are reserved by the copyright owner. \n\nPublished Online: 6 Jan 2019.", "abstract": "Herein is described a 1.5 m x 1.5 m reflectarray antenna designed to stow in a cylinder of 20 cm diameter and 9 cm height, and then be unfolded to provide an aperture suitable for radio frequency (RF) operations at X-band (8.4 GHz) and produce 39.6 dB of gain. The mass of the reflectarray, as measured for a full-scale prototype, is 1.75 kg. The reflectarray comprises a number of crossed-dipoles held 5 mm above a ground plane. The dipole layer and the ground plane are supported by thin planar composite facesheets; the separation between these facesheets is provided by thin composite collapsible 'S'-shaped-springs. The structure is divided into a number of quartz-epoxy composite strips arranged in concentric squares and connected to each other using slipping folds. The strips can be flattened, star-folded, and wrapped to package within the compact cylindrical volume. A full-scale prototype of this reflectarray was constructed and tested. Stowage in the design volume was successfully demonstrated, and all RF performance requirements were met, as shown by a pre-stowage RF test and a post-stowage RF test.", "date": "2019-01-06", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2019-2257", "id_number": "CaltechAUTHORS:20191112-154118926", "isbn": "978-1-62410-578-4", "book_title": "AIAA Scitech 2019 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191112-154118926", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2019-2257", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "Space-Solar-Power-Project" }, { "id": "GALCIT" } ] }, "doi": "10.2514/6.2019-2257", "pub_year": "2019", "author_list": "Arya, Manan; Sauder, Jonathan; et el." }, { "id": "https://authors.library.caltech.edu/records/9yjnt-yqa94", "eprint_id": 110824, "eprint_status": "archive", "datestamp": "2023-08-19 13:47:44", "lastmod": "2023-10-23 19:53:31", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ferraro-Serena", "name": { "family": "Ferraro", "given": "S." }, "orcid": "0000-0002-6038-7863" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "S." }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Topology Optimization of Composite Self-Deployable Thin Shells with Cutouts", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2019 by the American Institute of Aeronautics and Astronautics, Inc. \n\nPublished Online: 6 Jan 2019. \n\nThis work was supported by a NASA Space Technology Research Fellowship. S.F. would like to acknowledge the mentorship of Dr. William Doggett, NASA Langley, and Thibaud Talon, Caltech, for exchange of ideas.\n\nAccepted Version - Ferraro2019.pdf
", "abstract": "The paper presents topology optimization studies of selfs-deployable joints in thin-walled tubular structures. The joints are made entirely of ultra-thin, fiber reinforced composite materials. The objective of this research is to strategically position cutouts on the joints so that they can fold without failing, while maximizing the deployed bending stiffness. The optimal shape and position of cutouts are the results of concurrent topology optimization of these composite, thin-shell joints with geometrical non-linearities, due to their folding and self-deployable nature. Numerical methods to accurately detect failure are implemented and results from a novel level-set method for topology optimization are compared to results from classical parametric optimization and preliminary designs based on physical intuition.", "date": "2019-01-06", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2019-1524", "id_number": "CaltechAUTHORS:20210913-222227787", "isbn": "978-1-62410-578-4", "book_title": "AIAA Scitech 2019 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210913-222227787", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA Space Technology Research Fellowship" } ] }, "other_numbering_system": { "items": [ { "id": "2019-1524", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2019-1524", "primary_object": { "basename": "Ferraro2019.pdf", "url": "https://authors.library.caltech.edu/records/9yjnt-yqa94/files/Ferraro2019.pdf" }, "pub_year": "2019", "author_list": "Ferraro, S. and Pellegrino, S." }, { "id": "https://authors.library.caltech.edu/records/2xm5m-zcx96", "eprint_id": 100202, "eprint_status": "archive", "datestamp": "2023-08-19 13:43:04", "lastmod": "2024-01-14 22:03:54", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Castillo-Rogez-J-C", "name": { "family": "Castillo-Rogez", "given": "Julie C." } }, { "id": "Meech-K-J", "name": { "family": "Meech", "given": "Karen" }, "orcid": "0000-0002-2058-5670" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Landau-D", "name": { "family": "Landau", "given": "Damon" } } ] }, "title": "Approach to exploring interstellar objects and long-period comets", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2019 Published for the American Astronautical Society by Univelt, Incorporated. \n\nAAS 19-436. \n\nPart of this work is being carried out at the Jet Propulsion Laboratory, California Institute of Technology. This work is supported in part by the W.M. Keck Institute for Space Studies. K.J.M acknowledges support through NSF award AST-1617015 and support by the NASA SSO Near Earth Object Observations program 80NSSC18K0853. This study was initiated as part of a study hosted by the Keck Institute for Space Studies (KISS).\n\nPublished - AAS_KISS-Study-2019-v5.pdf
", "abstract": "This paper aims to identify the best approaches for exploring planetary bodies with very long orbital periods, i.e., bodies that approach Earth only once in a lifetime. This includes long-period comets (LPCs), and the newly discovered classes of Manx comets and interstellar objects (ISOs). Long-period comets are high scientific value targets, as indicated in the current Planetary Science Decadal Survey. Interstellar objects open the fascinating possibility to sample exoplanetary systems. Manxes hold the key to resolving long-time questions about the early history of our solar system. Specific strategies need to be implemented in order to approach bodies whose orbital properties are at the same time extreme and unpredictable. As ground-based telescope capabilities are greatly improving, it will soon become possible to detect LPCs more than ten years before they reach perihelion. On the other hand, the non- or weakly active Manx comets and ISOs require reactive exploration strategies. All of these bodies offer many challenges for close proximity observations that can be addressed by the deployment of multi-spacecraft architectures. We describe several concepts that leverage the many advantages offered by distributed sensors, fractionated payload, and various mother-daughter configurations to achieve high impact science within the reach of low-cost missions.", "date": "2019-01", "date_type": "published", "publisher": "American Astronautical Society", "place_of_pub": "San Diego, CA", "pagerange": "2115-2128", "id_number": "CaltechAUTHORS:20191205-094833503", "isbn": "9780877036593", "book_title": "Spaceflight Mechanics 2019", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191205-094833503", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "JPL/Caltech" }, { "agency": "Keck Institute for Space Studies (KISS)" }, { "agency": "NSF", "grant_number": "AST-1617015" }, { "agency": "NASA", "grant_number": "80NSSC18K0853" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Keck-Institute-for-Space-Studies" } ] }, "contributors": { "items": [ { "id": "Topputo-F", "name": { "family": "Topputo", "given": "Francesco" } }, { "id": "Sinclair-A-J", "name": { "family": "Sinclair", "given": "Andrew J." } }, { "id": "Wilkins-M-P", "name": { "family": "Wilkins", "given": "Matthew P." } }, { "id": "Zanetti-R", "name": { "family": "Zanetti", "given": "Renato" } } ] }, "primary_object": { "basename": "AAS_KISS-Study-2019-v5.pdf", "url": "https://authors.library.caltech.edu/records/2xm5m-zcx96/files/AAS_KISS-Study-2019-v5.pdf" }, "pub_year": "2019", "author_list": "Castillo-Rogez, Julie C.; Meech, Karen; et el." }, { "id": "https://authors.library.caltech.edu/records/ak4db-6jh60", "eprint_id": 100201, "eprint_status": "archive", "datestamp": "2023-08-19 13:42:54", "lastmod": "2024-01-14 22:03:52", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Marshall-M-A", "name": { "family": "Marshall", "given": "Michael A." } }, { "id": "Goel-Ashish", "name": { "family": "Goel", "given": "Ashish" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Attitude maneuver design for planar space solar power satellites", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2019 Published for the American Astronautical Society by Univelt, Incorporated. \n\nAAS 19-287. \n\nWe thank the Caltech Space Solar Power Project team, especially Dr. Dan Scharf (NASA-JPL), Dr. Richard Madonna (Caltech), and Dr. Terry Gdoutos (Caltech), for helpful comments and discussions. M.M. was supported by a NASA Space Technology Research Fellowship. Financial support from the Space Solar Power Project at Caltech is also acknowledged.\n\nOther - Marshall_2019p1451.pdf
", "abstract": "This paper investigates the attitude dynamics of a planar space solar power satellite (SSPS) by formulating the power-optimal guidance problem as a nonlinear trajectory optimization problem. The power-optimal guidance problem determines the orientation of an SSPS throughout its orbit that maximizes the amount of power transmitted to Earth. This transmitted power is a function of the relative geometry between the SSPS, the Sun, and the receiving station. Hence, it is inherently coupled to the attitude of the SSPS, i.e., the orientation that maximizes power transmission changes as the relative geometry changes. We first approximate the discretized trajectory optimization problem as a quadratic program (QP). We then solve the QP to obtain attitude trajectory designs for various orbits. These solutions highlight how maximizing transmitted power typically requires large slew maneuvers. Ultimately, by quantifying control and propellant requirements for various orbits, we emphasize how maneuver dynamics play an important role in SSPS design.", "date": "2019-01", "date_type": "published", "publisher": "American Astronautical Society", "place_of_pub": "San Diego, CA", "pagerange": "1451-1470", "id_number": "CaltechAUTHORS:20191205-093402644", "isbn": "9780877036593", "book_title": "Spaceflight Mechanics 2019", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191205-093402644", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA Space Technology Research Fellowship" }, { "agency": "Space Solar Power Project" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Space-Solar-Power-Project" } ] }, "contributors": { "items": [ { "id": "Topputo-F", "name": { "family": "Topputo", "given": "Francesco" } }, { "id": "Sinclair-A-J", "name": { "family": "Sinclair", "given": "Andrew J." } }, { "id": "Wilkins-M-P", "name": { "family": "Wilkins", "given": "Matthew P." } }, { "id": "Zanetti-R", "name": { "family": "Zanetti", "given": "Renato" } } ] }, "primary_object": { "basename": "Marshall_2019p1451.pdf", "url": "https://authors.library.caltech.edu/records/ak4db-6jh60/files/Marshall_2019p1451.pdf" }, "pub_year": "2019", "author_list": "Marshall, Michael A.; Goel, Ashish; et el." }, { "id": "https://authors.library.caltech.edu/records/xr8xv-19x05", "eprint_id": 89904, "eprint_status": "archive", "datestamp": "2023-08-19 12:56:58", "lastmod": "2023-10-18 23:04:55", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Shi-Xichen", "name": { "family": "Shi", "given": "Xichen" } }, { "id": "Kim-Kyunam", "name": { "family": "Kim", "given": "Kyunam" }, "orcid": "0000-0002-7803-1582" }, { "id": "Rahili-S", "name": { "family": "Rahili", "given": "Salar" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Nonlinear Control of Autonomous Flying Cars with Wings and\n Distributed Electric Propulsion", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2018 IEEE. \n\nThe authors thank M. Gharib, Director of CAST, for his support and technical guidance. The authors also thank R. Nemovi, M. Veismann, E. Yu, C. Dougherty, and J. Burdick at Caltech, and P. Tokumaru at AeroVironment.\n\nAccepted Version - CDC18_1784_FI.pdf
", "abstract": "Hybrid vertical take-off and landing vehicles (VTOL) with lift production from wings and distributed propulsive system present unique control challenges. Existing methods tend to stitch and switch different controllers specially designed for fixed-wing aircraft or multicopters. In this paper, we present a unified framework for designing controllers for such winged VTOL vehicles that are commonly found in recent flying car models. The proposed method is broken down into nonlinear control of both position and attitude with forces and moments\nas inputs, and real-time control allocation that integrates distributed propulsive actuation with conventional control surface deflection. We also present a strategy that avoids saturation of distributed propulsion control inputs. The effectiveness of the proposed framework is demonstrated through simulation and closed-loop flight experiment with our winged VTOL flying car prototype.", "date": "2018-12", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "5326-5333", "id_number": "CaltechAUTHORS:20180925-090601879", "isbn": "978-1-5386-1395-5", "book_title": "2018 IEEE Conference on Decision and Control (CDC)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180925-090601879", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/CDC.2018.8619578", "primary_object": { "basename": "CDC18_1784_FI.pdf", "url": "https://authors.library.caltech.edu/records/xr8xv-19x05/files/CDC18_1784_FI.pdf" }, "pub_year": "2018", "author_list": "Shi, Xichen; Kim, Kyunam; et el." }, { "id": "https://authors.library.caltech.edu/records/e700a-55z91", "eprint_id": 90233, "eprint_status": "archive", "datestamp": "2023-08-19 12:23:29", "lastmod": "2023-10-18 23:18:08", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Rahili-S", "name": { "family": "Rahili", "given": "Salar" } }, { "id": "Riviere-B", "name": { "family": "Riviere", "given": "Benjamin" } }, { "id": "Oliver-Suzanne", "name": { "family": "Oliver", "given": "Suzanne" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Optimal Routing for Autonomous Taxis using Distributed Reinforcement Learning", "ispublished": "unpub", "full_text_status": "public", "note": "Submitted - Conference_Ver_3.pdf
", "abstract": "In this paper, a learning-based optimal transportation\nalgorithm for autonomous taxis and ridesharing vehicles is\nintroduced. The goal is to design a mechanism to solve the routing problem for a fleet of autonomous vehicles in real-time in order to maximize the transportation company's profit. To solve this problem, the system is modeled as a Markov Decision Process (MDP) using past customers data. By solving the defined MDP, a centralized high-level planning recommendation is obtained, where this offline solution is used as an initial value for the real-time learning. Then, a distributed SARSA reinforcement learning algorithm is proposed to capture the model errors and the environment changes, such as variations in customer distributions in each area, traffic, and fares, thereby providing an accurate model and optimal policies in real-time. Agents are using only their local information and interaction, such as current passenger requests and estimates of neighbors' tasks and their optimal actions, to obtain the optimal policies in a distributed fashion. The agents use the estimated values of each action, provided by distributed SARSA reinforcement learning, in a distributed game-theory based task assignment to select their conflict-free customers. Finally, the customers data provided by the city of Chicago is used to validate the proposed algorithms.", "date": "2018-10-10", "date_type": "published", "publisher": "IEEE", "id_number": "CaltechAUTHORS:20181010-125618747", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181010-125618747", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "primary_object": { "basename": "Conference_Ver_3.pdf", "url": "https://authors.library.caltech.edu/records/e700a-55z91/files/Conference_Ver_3.pdf" }, "pub_year": "2018", "author_list": "Rahili, Salar; Riviere, Benjamin; et el." }, { "id": "https://authors.library.caltech.edu/records/c7bmk-rxf24", "eprint_id": 105156, "eprint_status": "archive", "datestamp": "2023-08-22 00:02:55", "lastmod": "2024-01-15 17:04:39", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Mac-Donald-K-A", "name": { "family": "Mac Donald", "given": "Kimberley" }, "orcid": "0000-0003-4512-9740" }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "Guruswami" }, "orcid": "0000-0002-2912-0001" } ] }, "title": "An Experimental Method to Induce and Measure Crack Propagation in Brittle Polymers with Heterogeneities", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Confocal microscopy; Digital Volume Correlation (DVC); Fracture mechanics; Heterogeneities; Soft polymers", "note": "\u00a9 2019 The Society for Experimental Mechanics, Inc. \n\nFirst Online: 19 September 2018. \n\nThis material is based upon work supported by the National Science Foundation Graduate Research Fellowship Grant No. DGE-1144469 and Designing Materials to Revolutionize and Engineer our Future (DMREF) Award No. DMS-1535083. Imaging was performed in the Biological Imaging Facility, with the support of the Caltech Beckman Institute and the Arnold and Mabel Beckman Foundation.", "abstract": "Facture mechanics of heterogeneous brittle solids is a field of active research due to the recent developments in additive manufacturing to fabricate components with complex engineered microstructures. The majority of experimental work in crack propagation uses data from a single plane, usually on free surfaces, to measure the displacement field around the crack and the crack tip location. These measurements are used to determine the crack tip fields and fracture toughness which provides insights about the failure of a material. However, it is well known from three dimensional theory and experiments that the crack front shape and stress distribution is not constant through the thickness of a specimen. When toughening heterogeneities are added to a material, the theories and mechanics become significantly more complex. To better understand these stresses and shapes for both homogeneous and heterogeneous materials, an experimental method has been developed to induce steady-state crack propagation in thin, brittle hydrogel polymers. A microfilament needle inserted into the specimens allows for fluid to enter the crack and exert pressure on the crack surface, which effectively wedges the crack open. Distributed fluorescent microspheres serve as a speckle pattern for Digital Volume Correlation (DVC) of volumetric images captured using confocal microscopy. The DVC displacement field allows for determination of the 3D crack tip fields. This study seeks to provide an enhanced understanding of the three dimensional nature of crack interactions with heterogeneities and renucleation events, which can significantly improve our ability to design material toughness.", "date": "2018-09-19", "date_type": "published", "publisher": "Springer", "place_of_pub": "Cham", "pagerange": "21-23", "id_number": "CaltechAUTHORS:20200828-160943420", "isbn": "978-3-319-95878-1", "book_title": "Fracture, Fatigue, Failure and Damage Evolution", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200828-160943420", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF Graduate Research Fellowship", "grant_number": "DGE-1144469" }, { "agency": "NSF", "grant_number": "DMS-1535083" }, { "agency": "Caltech Beckman Institute" }, { "agency": "Arnold and Mabel Beckman Foundation" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Carroll-Jay", "name": { "family": "Carroll", "given": "Jay" } }, { "id": "Xia-Shuman", "name": { "family": "Xia", "given": "Shuman" } }, { "id": "Beese-A-M", "name": { "family": "Beese", "given": "Allison M." } }, { "id": "Berke-R-B", "name": { "family": "Berke", "given": "Ryan B." } }, { "id": "Pataky-G-J", "name": { "family": "Pataky", "given": "Garrett J." } } ] }, "doi": "10.1007/978-3-319-95879-8_5", "pub_year": "2018", "author_list": "Mac Donald, Kimberley and Ravichandran, Guruswami" }, { "id": "https://authors.library.caltech.edu/records/8ajnp-7c720", "eprint_id": 105143, "eprint_status": "archive", "datestamp": "2023-08-22 00:02:47", "lastmod": "2024-01-15 17:04:37", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Avellar-Louisa", "name": { "family": "Avellar", "given": "Louisa" } }, { "id": "Reese-Tucker", "name": { "family": "Reese", "given": "Tucker" } }, { "id": "Bhattacharya-K", "name": { "family": "Bhattacharya", "given": "Kaushik" }, "orcid": "0000-0003-2908-5469" }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "Guruswami" }, "orcid": "0000-0002-2912-0001" } ] }, "title": "Cohesive Zone Smoothing of Bending Stiffness Heterogeneities in Tape Peeling Experiments", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Fracture; Cohesive zone; Peeling; Laminates; Heterogeneous materials", "note": "\u00a9 2019 The Society for Experimental Mechanics, Inc. \n\nFirst Online: 19 September 2018. \n\nWe gratefully acknowledge the support of the National Science Foundation Award No. DMS-1535083 under the Designing Materials to Revolutionize and Engineer our Future (DMREF) program. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE-1144469.", "abstract": "This work studies the interaction between the cohesive zone and elastic stiffness heterogeneity in the peeling of an adhesive tape from a rigid substrate. It is understood that elastic stiffness heterogeneities can greatly enhance the adhesion of a tape without changing the properties of the interface. However, in experiments performed on adhesive tapes with both an elastic stiffness heterogeneity and a substantial cohesive zone, muted adhesion enhancement was observed. It is proposed that the cohesive zone acts to smooth out the effect of the discontinuity at the edge of the elastic stiffness heterogeneities, suppressing their effect on adhesion. This work presents peel tests performed with heterogeneously layered 3 M 810 tape that demonstrate the muted enhancement. Additionally, numerical simulations further investigating the interaction between elastic heterogeneity and cohesive zone are presented.", "date": "2018-09-19", "date_type": "published", "publisher": "Springer", "place_of_pub": "Cham", "pagerange": "73-76", "id_number": "CaltechAUTHORS:20200828-121917087", "isbn": "978-3-319-95878-1", "book_title": "Fracture, Fatigue, Failure and Damage Evolution", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200828-121917087", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "DMS-1535083" }, { "agency": "NSF Graduate Research Fellowship", "grant_number": "DGE-1144469" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Carroll-Jay", "name": { "family": "Carroll", "given": "Jay" } }, { "id": "Xia-Shuman", "name": { "family": "Xia", "given": "Shuman" } }, { "id": "Beese-A-M", "name": { "family": "Beese", "given": "Allison M." } }, { "id": "Berke-R-B", "name": { "family": "Berke", "given": "Ryan B." } }, { "id": "Pataky-G-J", "name": { "family": "Pataky", "given": "Garrett J." } } ] }, "doi": "10.1007/978-3-319-95879-8_12", "pub_year": "2018", "author_list": "Avellar, Louisa; Reese, Tucker; et el." }, { "id": "https://authors.library.caltech.edu/records/mxdy0-tr609", "eprint_id": 94442, "eprint_status": "archive", "datestamp": "2023-08-19 10:52:53", "lastmod": "2023-10-20 17:57:52", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Li-Yang", "name": { "family": "Li", "given": "Yang" }, "orcid": "0000-0002-4939-8174" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Design of Structures With Multiple Equilibrium Configurations", "ispublished": "unpub", "full_text_status": "public", "keywords": "Equilibrium (Physics), Design", "note": "\u00a9 2018 by ASME. \n\nPaper No. DETC2018-86157.", "abstract": "Being able to design structures with multiple equilibrium configurations is the basis for the design of multi-stable structures, which are of interest for future research on multi-configuration structures that require 'simple' actuation schemes. It is already known that adding elastic springs to a rigid mechanism can create structures with multiple equilibrium configurations. The spring properties, such as their rest positions, can be taken as design parameters that can be used to achieve specific equilibrium configurations of the structure. This paper provides a linearized formulation for the equilibrium constraints that can be solved for the rest positions of the springs. This method allows the design of specific equilibrium configurations. It can also handle more complex problems and is easier to solve in comparison to existent techniques. An example design of a four-bar linkage that has 5 equilibrium configurations is presented.", "date": "2018-08", "date_type": "published", "publisher": "American Society of Mechanical Engineers", "place_of_pub": "New York, NY", "pagerange": "Art. No. V05BT07A063", "id_number": "CaltechAUTHORS:20190404-081554007", "isbn": "978-0-7918-5181-4", "book_title": "42nd Mechanisms and Robotics Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190404-081554007", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1115/DETC2018-86157", "pub_year": "2018", "author_list": "Li, Yang and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/r1424-xmc64", "eprint_id": 88874, "eprint_status": "archive", "datestamp": "2023-08-19 10:44:48", "lastmod": "2023-10-18 22:22:08", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Nakka-Yashwanth-K", "name": { "family": "Nakka", "given": "Yashwanth Kumar" }, "orcid": "0000-0001-7897-3644" }, { "id": "Foust-Rebecca", "name": { "family": "Foust", "given": "Rebecca C." }, "orcid": "0000-0003-1470-1716" }, { "id": "Lupu-E-S", "name": { "family": "Lupu", "given": "Elena Sorina" }, "orcid": "0000-0002-3968-2630" }, { "id": "Elliott-D-B", "name": { "family": "Elliott", "given": "David B." } }, { "id": "Crowell-I-S", "name": { "family": "Crowell", "given": "Irene S." } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Hadaegh-F-Y", "name": { "family": "Hadaegh", "given": "Fred Y." } } ] }, "title": "A Six Degree-of-Freedom Spacecraft Dynamics Simulator for Formation Control Research", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2018 AIAA.\n\nThe authors acknowledge the work done by R. Eric Rasmussen at Guidance Dynamics in designing and constructing the spacecraft simulators. Many thanks to Jui Hung Sun for creating the thruster experimental setup and designing a previous version of the thruster control board, and to Karen Chen for designing the reaction wheel brackets and performing structural analysis of the reaction wheels. The work of Rebecca Foust was supported by a NASA Space Technology Research Fellowship, government sponsorship is acknowledged.\n\nPublished - 2018_AAS_AIAA.pdf
Accepted Version - AAS-AIAA-18-476.pdf
", "abstract": "This paper presents a new six-degree-of-freedom robotic spacecraft simulator, the Multi-Spacecraft Testbed for Autonomy Research (M-STAR), for testing formation\nguidance, relative navigation, and control algorithms. The simulator dynamics are governed by five degrees of frictionless translational and rotational air-bearing\nmotion and one degree of kinematic motion in the gravity direction with flight-like actuators, in a 1-g environment. M-STAR is designed to be modular and accommodates\n3-DOF, 4-DOF, 5-DOF, and 6-DOF operation with minimal mechanical modifications. The simulator is modelled as a 3-D pendulum on a floating platform with sixteen thrusters and four reaction wheels as on-board actuators. Based\non this plant model, a nonlinear hierarchical control law is proposed for position and attitude trajectory tracking. A weighted generalized pseudo-inverse strategy\nfor control allocation to map control inputs to actuator inputs is discussed. The thruster actuation model for mapping smooth allocated input to non-smooth actuator\ninput that achieves equivalent performance is derived. The control law, allocation scheme, and thruster model are tested on the simulator for real-time position tracking control using a Robot Operating System (ROS) based software\nframework.", "date": "2018-08", "date_type": "published", "publisher": "AIAA", "id_number": "CaltechAUTHORS:20180816-145831065", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180816-145831065", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA Space Technology Research Fellowship" } ] }, "other_numbering_system": { "items": [ { "id": "AAS 18-476", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "primary_object": { "basename": "2018_AAS_AIAA.pdf", "url": "https://authors.library.caltech.edu/records/r1424-xmc64/files/2018_AAS_AIAA.pdf" }, "related_objects": [ { "basename": "AAS-AIAA-18-476.pdf", "url": "https://authors.library.caltech.edu/records/r1424-xmc64/files/AAS-AIAA-18-476.pdf" } ], "pub_year": "2018", "author_list": "Nakka, Yashwanth Kumar; Foust, Rebecca C.; et el." }, { "id": "https://authors.library.caltech.edu/records/zcs46-c9p80", "eprint_id": 92007, "eprint_status": "archive", "datestamp": "2023-08-19 10:38:36", "lastmod": "2024-01-14 21:23:51", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lombardo-S", "name": { "family": "Lombardo", "given": "Simona" }, "orcid": "0000-0002-2161-8104" }, { "id": "Behaghel-T", "name": { "family": "Behaghel", "given": "Thibault" } }, { "id": "Chambion-B", "name": { "family": "Chambion", "given": "Bertrand" } }, { "id": "Jahn-W", "name": { "family": "Jahn", "given": "Wilfried" } }, { "id": "Hugot-E", "name": { "family": "Hugot", "given": "Emmanuel" }, "orcid": "0000-0002-5879-6318" }, { "id": "Muslimov-E-R", "name": { "family": "Muslimov", "given": "Eduard" } }, { "id": "Roulet-M", "name": { "family": "Roulet", "given": "Melanie" } }, { "id": "Ferrari-M", "name": { "family": "Ferrari", "given": "Marc" } }, { "id": "Gaschet-C", "name": { "family": "Gaschet", "given": "Christophe" } }, { "id": "Henry-M-D", "name": { "family": "Henry", "given": "David" }, "orcid": "0000-0002-5201-0644" }, { "id": "Caplet-S", "name": { "family": "Caplet", "given": "St\u00e9phane" } } ] }, "title": "Curved CMOS sensor: characterization of the first fully functional prototype", "ispublished": "unpub", "full_text_status": "public", "keywords": "CMOS, curved detector, characterization, noise properties, dark current", "note": "\u00a9 2018 Society of Photo-Optical Instrumentation Engineers (SPIE). \n\nThe authors acknowledge the support of the European Research council through the H2020 - ERC-STG-2015 678777 ICARUS program. This activity was partially funded by the French Research Agency (ANR) through the LabEx FOCUS ANR-11-LABX-0013.\n\nPublished - 1067910.pdf
", "abstract": "Many are the optical designs that generate curved focal planes for which field flattener must be implemented. This generally implies the use of more optical elements and a consequent loss of throughput and performances. With the recent development of curved sensor this can be avoided. This new technology has been gathering more and more attention from a very broad community, as the potential applications are multiple: from low-cost commercial to high impact scientific systems, to mass-market and on board cameras, defense and security, and astronomical community.\n\nWe describe here the first concave curved CMOS detector developed within a collaboration between CNRS-LAM and CEA-LETI. This fully-functional detector 20Mpix (CMOSIS CMV20000) has been curved down to a radius of R_c =150mm over a size of 24x32mm^2. We present here the methodology adopted for its characterization and describe in detail all the results obtained. We also discuss the main components of noise, such as the readout noise, the fixed pattern noise and the dark current. Finally we provide a comparison with the at version of the same sensor in order to establish the impact of the curving process on the main characteristics of the sensor.", "date": "2018-07-31", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "Art. No. 1067910", "id_number": "CaltechAUTHORS:20190102-155138551", "isbn": "9781510618848", "book_title": "Optics, Photonics, and Digital Technologies for Imaging Applications V", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190102-155138551", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "European Research Council (ERC)", "grant_number": "678777" }, { "agency": "Agence Nationale pour la Recherche (ANR)", "grant_number": "ANR-11-LABX-0013" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Schelkens-P", "name": { "family": "Schelkens", "given": "Peter" } }, { "id": "Ebrahimi-T", "name": { "family": "Ebrahimi", "given": "Touradj" } }, { "id": "Crist\u00f3bal-G", "name": { "family": "Crist\u00f3bal", "given": "Gabriel" } } ] }, "doi": "10.1117/12.2307170", "primary_object": { "basename": "1067910.pdf", "url": "https://authors.library.caltech.edu/records/zcs46-c9p80/files/1067910.pdf" }, "pub_year": "2018", "author_list": "Lombardo, Simona; Behaghel, Thibault; et el." }, { "id": "https://authors.library.caltech.edu/records/7nr6f-hem79", "eprint_id": 91585, "eprint_status": "archive", "datestamp": "2023-08-19 10:32:06", "lastmod": "2024-01-14 21:16:29", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lombardo-S", "name": { "family": "Lombardo", "given": "Simona" }, "orcid": "0000-0002-2161-8104" }, { "id": "Behaghel-T", "name": { "family": "Behaghel", "given": "Thibault" } }, { "id": "Chambion-B", "name": { "family": "Chambion", "given": "Bertrand" } }, { "id": "Jahn-W", "name": { "family": "Jahn", "given": "Wilfried" } }, { "id": "Hugot-E", "name": { "family": "Hugot", "given": "Emmanuel" }, "orcid": "0000-0002-5879-6318" }, { "id": "Muslimov-E", "name": { "family": "Muslimov", "given": "Eduard" }, "orcid": "0000-0002-3242-9894" }, { "id": "Roulet-M", "name": { "family": "Roulet", "given": "Melanie" } }, { "id": "Ferrari-M", "name": { "family": "Ferrari", "given": "Marc" } }, { "id": "Gaschet-C", "name": { "family": "Gaschet", "given": "Christophe" } }, { "id": "Caplet-S", "name": { "family": "Caplet", "given": "St\u00e9phane" } }, { "id": "Henry-M-D", "name": { "family": "Henry", "given": "David" }, "orcid": "0000-0002-5201-0644" } ] }, "title": "Curved detectors developments and characterization: application to astronomical instruments", "ispublished": "unpub", "full_text_status": "public", "keywords": "CMOS, curved detector, characterization, noise properties, dark current", "note": "\u00a9 2018 Society of Photo-Optical Instrumentation Engineers (SPIE). \n\nThe authors acknowledge the support of the European Research council through the H2020 - ERC-STG-2015 678777 ICARUS program. This activity was partially funded by the French Research Agency (ANR) through the LabEx FOCUS ANR-11-LABX-0013.\n\nPublished - 107090U.pdf
", "abstract": "Many astronomical optical systems have the disadvantage of generating curved focal planes requiring flattening optical elements to project the corrected image on at detectors. The use of these designs in combination with a classical at sensor implies an overall degradation of throughput and system performances to obtain the proper corrected image. With the recent development of curved sensor this can be avoided. This new technology has been gathering more and more attention from a very broad community, as the potential applications are multiple: from low-cost commercial to high impact scientific systems, to mass-market and on board cameras, defense and security, and astronomical community. We describe here the first concave curved CMOS detector developed within a collaboration between CNRS- LAM and CEA-LETI. This fully-functional detector 20 Mpix (CMOSIS CMV20000) has been curved down to a radius of R_c =150mm over a size of 24x32mm^2. We present here the methodology adopted for its characterization and describe in detail all the results obtained. We also discuss the main components of noise, such as the readout noise, the fixed pattern noise and the dark current. Finally we provide a comparison with the at version of the same sensor in order to establish the impact of the curving process on the main characteristics of the sensor.", "date": "2018-07-20", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "Art. No. 107090U", "id_number": "CaltechAUTHORS:20181207-145745524", "isbn": "9781510619715", "book_title": "High Energy, Optical, and Infrared Detectors for Astronomy VIII", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181207-145745524", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "European Research Council (ERC)", "grant_number": "678777" }, { "agency": "Agence Nationale pour la Recherche (ANR)", "grant_number": "ANR-11-LABX-0013" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Holland-A-D", "name": { "family": "Holland", "given": "Andrew D." } }, { "id": "Beletic-J", "name": { "family": "Beletic", "given": "James" } } ] }, "doi": "10.1117/12.2312654", "primary_object": { "basename": "107090U.pdf", "url": "https://authors.library.caltech.edu/records/7nr6f-hem79/files/107090U.pdf" }, "pub_year": "2018", "author_list": "Lombardo, Simona; Behaghel, Thibault; et el." }, { "id": "https://authors.library.caltech.edu/records/zkbtw-4ds28", "eprint_id": 87976, "eprint_status": "archive", "datestamp": "2023-08-19 10:14:22", "lastmod": "2024-01-14 20:28:04", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Breckinridge-J-B", "name": { "family": "Breckinridge", "given": "James B." }, "orcid": "0000-0002-9488-098X" }, { "id": "Harvey-J-E", "name": { "family": "Harvey", "given": "James E." } }, { "id": "Crabtree-K", "name": { "family": "Crabtree", "given": "Karlton" } }, { "id": "Hull-T", "name": { "family": "Hull", "given": "Tony" } } ] }, "title": "Exoplanet telescope diffracted light minimized: the pinwheel-pupil solution", "ispublished": "unpub", "full_text_status": "public", "keywords": "Telescopes, Exoplanet imaging, segmented mirrors, pinwheel pupil, diffraction control, scattered light, starlight suppression, structures", "note": "\u00a9 2018 Society of Photo-Optical Instrumentation Engineers (SPIE). \n\nWe wish to acknowledge the work on the Pinwheel Pupil, performed by Dr. Kathryn Jackson during her Post Doc assignment at Caltech. This work was supported in part by a NASA TDEM15 research grant #NNX17AB29G awarded by NASA Science Mission Directorate to the College of Optical Sciences at the University of Arizona. This work was also supported in part by a NASA contract # NNX17AD08G awarded by STMD, Early Stage Innovation program to Professor Pellegrino of Caltech.\n\nPublished - 106981P.pdf
", "abstract": "Terrestrial exoplanets shine in light reflected from a parent star. Optical spectra are required to provide evidence of a life-supporting environment. Exoplanets are very faint and their optical spectra are contaminated by the spectrum of the parent star. High angular resolution provided by large apertures is needed to distinguish between the spectrum of the exoplanet and its star. Today, large aperture telescopes use segmented primary mirrors that employ close-packed hexagonal segments. The telescope primary mirror is periodically discontinuous with straight lines. These discontinuities scatter unwanted radiation from the much brighter parent star across the field of view to obscure the light from the very faint terrestrial exoplanet. These discontinuities, which mimic a diffraction grating, result in a non-uniform distribution of background light across the image plane. This non-uniformity masks or hides exoplanets from view, to reduce the number of exoplanets that can be observed with a large aperture telescope or to reduce the quality of spectra and thus lead to misinterpretation of data. Here we introduce the concept of the pinwheel pupil whose unique diffraction pattern significantly reduces the non-uniform distribution of background radiation. Diffraction patterns from pinwheel pupils are compared to the monolithic filled aperture, the classical Cassegrain, the 60-degree symmetry of the hexagonal segments (JWST, E-ELT, etc.). Diffraction \"spikes\" are reduced by at least 105. We discuss the \"pinwheel pupil\" advantages to spectroscopy, image processing, and observatory operations. We show that, segment fabrication of curved-sided mirrors is not more difficult than fabrication of hexagonal mirror segments. . This is the report of quantitative study of Fraunhofer (far field) diffraction patterns produced by three different topologies or architectures of mirror segmentation, when illuminated by a plane wave of monochromatic white-light. A plot, in angular units of the intensity as a function of azimuth, Phi_f , within annular rings at different FOVs, centered on the system axis of the diffraction pattern will be presented. The advantages of the segmented pinwheel pupil is discussed.", "date": "2018-07-06", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "Art. No. 106981P", "id_number": "CaltechAUTHORS:20180718-153413745", "isbn": "9781510619494", "book_title": "Space Telescopes and Instrumentation 2018: Optical, Infrared, and Millimeter Wave", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180718-153413745", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA", "grant_number": "NNX17AB29G" }, { "agency": "NASA", "grant_number": "NNX17AD08G" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Lystrup-M", "name": { "family": "Lystrup", "given": "Makenzie" } }, { "id": "MacEwen-H-A", "name": { "family": "MacEwen", "given": "Howard A." } }, { "id": "Fazio-G-G", "name": { "family": "Fazio", "given": "Giovanni G." } }, { "id": "Batalha-N-M", "name": { "family": "Batalha", "given": "Natalie" } }, { "id": "Siegler-N", "name": { "family": "Siegler", "given": "Nicholas" } }, { "id": "Tong-Edward-C", "name": { "family": "Tong", "given": "Edward C." } } ] }, "doi": "10.1117/12.2311811", "primary_object": { "basename": "106981P.pdf", "url": "https://authors.library.caltech.edu/records/zkbtw-4ds28/files/106981P.pdf" }, "pub_year": "2018", "author_list": "Breckinridge, James B.; Harvey, James E.; et el." }, { "id": "https://authors.library.caltech.edu/records/4q5b0-vr031", "eprint_id": 87973, "eprint_status": "archive", "datestamp": "2023-08-19 10:14:11", "lastmod": "2024-01-14 20:27:59", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Pfisterer-R-N", "name": { "family": "Pfisterer", "given": "Richard N." } }, { "id": "Harvey-J-E", "name": { "family": "Harvey", "given": "James E." } }, { "id": "Breckinridge-J-B", "name": { "family": "Breckinridge", "given": "James B." }, "orcid": "0000-0002-9488-098X" } ] }, "title": "The role of narrow-angle forward surface scatter and particulate scatter in exoplanet exploration", "ispublished": "unpub", "full_text_status": "public", "keywords": "stray light, BSDF, particulates, exoplanets", "note": "\u00a9 2018 Society of Photo-Optical Instrumentation Engineers (SPIE).\n\nPublished - 106985F.pdf
", "abstract": "It is often thought that because of the very small solid angle subtended by the field-of-view of the coronagraph, scattered light from optical surfaces will have no effect on images recorded for terrestrial exoplanet spectroscopy. In this paper, we examine mirror surface scatter and particulate contamination scatter as sources of background light or noise signal in large aperture terrestrial exoplanet telescope/coronagraph systems. Scattered light control to one part in 10^(+10) or better is required for exoplanet exploration. We will discuss the optical fabrication tolerances necessary to minimize narrowangle forward scatter and their relative effects upon direct imaging coronagraph instruments used to characterize terrestrial exoplanets.", "date": "2018-07-06", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "Art. No. 106985F", "id_number": "CaltechAUTHORS:20180718-152258159", "isbn": "9781510619494", "book_title": "Space Telescopes and Instrumentation 2018: Optical, Infrared, and Millimeter Wave", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180718-152258159", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Lystrup-M", "name": { "family": "Lystrup", "given": "Makenzie" } }, { "id": "MacEwen-H-A", "name": { "family": "MacEwen", "given": "Howard A." } }, { "id": "Fazio-G-G", "name": { "family": "Fazio", "given": "Giovanni G." } }, { "id": "Batalha-N-M", "name": { "family": "Batalha", "given": "Natalie" } }, { "id": "Siegler-N", "name": { "family": "Siegler", "given": "Nicholas" } }, { "id": "Tong-Edward-C", "name": { "family": "Tong", "given": "Edward C." } } ] }, "doi": "10.1117/12.2314229", "primary_object": { "basename": "106985F.pdf", "url": "https://authors.library.caltech.edu/records/4q5b0-vr031/files/106985F.pdf" }, "pub_year": "2018", "author_list": "Pfisterer, Richard N.; Harvey, James E.; et el." }, { "id": "https://authors.library.caltech.edu/records/jnf4j-c8s17", "eprint_id": 87977, "eprint_status": "archive", "datestamp": "2023-08-19 10:14:27", "lastmod": "2024-01-14 20:28:06", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Breckinridge-J-B", "name": { "family": "Breckinridge", "given": "J. B." }, "orcid": "0000-0002-9488-098X" }, { "id": "Kupinski-M", "name": { "family": "Kupinski", "given": "M." } }, { "id": "Davis-J", "name": { "family": "Davis", "given": "J." } }, { "id": "Daugherty-B", "name": { "family": "Daugherty", "given": "B." } }, { "id": "Chipman-R-A", "name": { "family": "Chipman", "given": "R. A." } } ] }, "title": "Terrestrial exoplanet coronagraph image quality polarization aberrations in Habex", "ispublished": "unpub", "full_text_status": "public", "keywords": "Exoplanet, coronagraph, polarization aberration, HabEx, telescopes, coatings, physical optics", "note": "\u00a9 2018 Society of Photo-Optical Instrumentation Engineers (SPIE). \n\nThis work was supported in part by NASA TDEM15 research grant #NNX17AB29G awarded by the NASA Science Mission Directorate to James Breckinridge, PI, at the College of Optical Sciences at the University of Arizona.\n\nPublished - 106981D.pdf
", "abstract": "Direct imaging and spectroscopy of terrestrial exoplanets requires the control of vector electromagnetic fields to approximately one part in ten to the fifth over a few milliarc second FOV to achieve the necessary 10-10 intensity contrast levels. Observations using space telescopes are necessary to achieve these levels of diffracted and scattered light control. The highly reflecting metal mirrors and their coatings needed to image these very faint exoplanets introduce polarization into the wavefront, which, in turn affects image quality and reduces exoplanet yield unless corrected. To identify and create the technologies and the electro-optical/mechanical-spacecraft systems models that will achieve these levels, NASA is currently developing two mission concepts, each with their own hardware vision. These are: The Habex, a habitable planet explorer and the LUVOIR, a Large Ultra-Violet Optical-Infrared space telescope system. This paper reports the results of polarization ray-tracing the HabEx detailed optical prescription provided by the project to the authors in the fall of 2017. Diattenuation and retardance across both the exit pupil associated with the occulting mask and the exit pupil associated with the coronagraph image plane are given as well as the corresponding Jones pupil matrices. These are calculated assuming isotropic coatings on all mirrors. Analysis and physical measurements indicates that the specification of the primary mirror for exoplanet coronagraphs will need to include a constraint on spatially varying polarization reflectivity (anisotropic coatings). The Jones exit-pupil phase terms, phi XX and phi YY just before the occulting mask differ in shape and are displaced one from the other by about 10 milli-waves. This shows that A/O, which corrects for geometric path differences, cannot completely correct for wavefront errors introduced by polarization for this particular prescription for HabEx. We suggest that these differences may be corrected by adjusting the opto-mechanical design to change angles of incidence on mirrors and corrected by adjusting the design of the dielectric coatings on the highly-reflecting mirror surfaces. Super-posing the phase of XX onto the phase of YY and then correcting using A/O will assure maximum power transmittance through the system and best contrast. These aspects require further investigation.", "date": "2018-07-06", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "Art. No. 106981D", "id_number": "CaltechAUTHORS:20180718-154034697", "isbn": "9781510619494", "book_title": "Space Telescopes and Instrumentation 2018: Optical, Infrared, and Millimeter Wave", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180718-154034697", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA", "grant_number": "NNX17AB29G" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Lyastrup-M", "name": { "family": "Lystrup", "given": "Makenzie" } }, { "id": "MacEwen-H-A", "name": { "family": "MacEwen", "given": "Howard A." } }, { "id": "Fazio-G-G", "name": { "family": "Fazio", "given": "Giovanni G." } }, { "id": "Batalha-N-M", "name": { "family": "Batalha", "given": "Natalie" } }, { "id": "Siegler-N", "name": { "family": "Siegler", "given": "Nicholas" } }, { "id": "Tong-Edward-C", "name": { "family": "Tong", "given": "Edward C." } } ] }, "doi": "10.1117/12.2311880", "primary_object": { "basename": "106981D.pdf", "url": "https://authors.library.caltech.edu/records/jnf4j-c8s17/files/106981D.pdf" }, "pub_year": "2018", "author_list": "Breckinridge, J. B.; Kupinski, M.; et el." }, { "id": "https://authors.library.caltech.edu/records/cgckk-hpy45", "eprint_id": 87974, "eprint_status": "archive", "datestamp": "2023-08-19 10:14:16", "lastmod": "2024-01-14 20:28:01", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Harvey-J-E", "name": { "family": "Harvey", "given": "James E." } }, { "id": "Irvin-R-G", "name": { "family": "Irvin", "given": "Ryan G." } }, { "id": "Crabtree-K", "name": { "family": "Crabtree", "given": "Karlton" } }, { "id": "Pfisterer-R-N", "name": { "family": "Pfisterer", "given": "Richard N." } }, { "id": "Breckinridge-J-B", "name": { "family": "Breckinridge", "given": "James B." }, "orcid": "0000-0002-9488-098X" } ] }, "title": "Diffraction analysis of large segmented mirror concepts for exoplanet exploration", "ispublished": "unpub", "full_text_status": "public", "keywords": "Exoplanet exploration, Large segmented mirrors, Pinwheel pupil, Diffraction effects", "note": "\u00a9 2018 Society of Photo-Optical Instrumentation Engineers (SPIE).\n\nPublished - 106981Q.pdf
", "abstract": "Diffraction effects of large segmented mirror gaps and secondary mirror support struts produce diffraction peaks or flares that are a detriment to exoplanet detection. In this paper we present detailed parametric diffraction analyses of an innovative \"Pinwheel Pupil\" segmented mirror concept utilizing curved segment gaps and secondary support struts that can potentially eliminate these diffraction flares that can obscure a faint exoplanet image. The resulting numerical diffraction performance predictions are quantitatively compared to that of both ideal monolithic circular pupils and classical annular pupils with straight secondary mirror struts. We utilize performance \u2013 based merit functions consisting of both radial and azimuthal profiles of the resulting telescope point spread function.", "date": "2018-07-06", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "Art. No. 106981Q", "id_number": "CaltechAUTHORS:20180718-152857173", "isbn": "9781510619494", "book_title": "Space Telescopes and Instrumentation 2018: Optical, Infrared, and Millimeter Wave", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180718-152857173", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Lystrup-M", "name": { "family": "Lystrup", "given": "Makenzie" } }, { "id": "MacEwen-H-A", "name": { "family": "MacEwen", "given": "Howard A." } }, { "id": "Fazio-G-G", "name": { "family": "Fazio", "given": "Giovanni G." } }, { "id": "Batalha-N-M", "name": { "family": "Batalha", "given": "Natalie" } }, { "id": "Siegler-N", "name": { "family": "Siegler", "given": "Nicholas" } }, { "id": "Tong-Edward-C", "name": { "family": "Tong", "given": "Edward C." } } ] }, "doi": "10.1117/12.2313999", "primary_object": { "basename": "106981Q.pdf", "url": "https://authors.library.caltech.edu/records/cgckk-hpy45/files/106981Q.pdf" }, "pub_year": "2018", "author_list": "Harvey, James E.; Irvin, Ryan G.; et el." }, { "id": "https://authors.library.caltech.edu/records/t9t45-cey48", "eprint_id": 97952, "eprint_status": "archive", "datestamp": "2023-08-19 09:53:45", "lastmod": "2023-10-18 16:54:36", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Dawson-S-T-M", "name": { "family": "Dawson", "given": "Scott T. M." }, "orcid": "0000-0002-0020-2097" }, { "id": "Saxton-Fox-T", "name": { "family": "Saxton-Fox", "given": "Theresa" }, "orcid": "0000-0003-1328-4148" }, { "id": "McKeon-B-J", "name": { "family": "McKeon", "given": "Beverley J." }, "orcid": "0000-0003-4220-1583" } ] }, "title": "Modeling Passive Scalar Dynamics in Wall-Bounded Turbulence using Resolvent Analysis", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2018 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 24 Jun 2018.", "abstract": "This work develops a framework for studying the behavior of a passive scalar field in incompressible wall-bounded turbulence using \u00b7the resolvent operator. This approach expresses the stale of the system as the result of applying a linear (resolvent) operator to the nonlinear terms in the governing Navier-Stokes equations. By augmenting the system with a passive scalar equation, this formulation is used to study the relationship between velocity and scalar fluctuations. Additional insight into the mechanisms responsible for driving scalar fluctuations is attained by considering the resolvent form of the passive scalar equation in isolation from the momentum equations. We demonstrate that the passive scalar resolvent operator admits rescaling properties that relates the behavior or scalar fields with different diffusivities, and investigate the ability of this modeling framework to predict statistical properties of the fluctuating scalar field.", "date": "2018-06-24", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2018-4042", "id_number": "CaltechAUTHORS:20190816-111358078", "isbn": "978-1-62410-553-1", "book_title": "2018 Fluid Dynamics Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190816-111358078", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2018-4042", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2018-4042", "pub_year": "2018", "author_list": "Dawson, Scott T. M.; Saxton-Fox, Theresa; et el." }, { "id": "https://authors.library.caltech.edu/records/px2m7-dpw83", "eprint_id": 97950, "eprint_status": "archive", "datestamp": "2023-08-19 09:53:42", "lastmod": "2023-10-18 16:54:28", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lawson-Joel-M", "name": { "family": "Lawson", "given": "Joel M." }, "orcid": "0000-0002-3042-0909" }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "Joanna M." }, "orcid": "0000-0003-3129-5035" } ] }, "title": "Design of Conventional and Detonation-Driven Hypervelocity Expansion Tubes", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2018 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 24 Jun 2018. \n\nThe authors would like to thank the Office of Naval Research for supporting this work under the award N00014-16-1-2503, entitled 'Advancing Transition Experiments in High Enthalpy Flows'.\n\nAccepted Version - 541449.pdf
", "abstract": "Freestream disturbances can have a significant impact on studies of boundary layer transition in ground tests, including experiments in high-enthalpy hypersonic facilities such as an expansion tube. Freest ream noise reduction in expansion tubes can be achieved by increasing the driver-to-driven pressure ratio p\u2084/p\u2081, so we seek .methods to increase this ratio in Caltech's HET facility. Towards this end, an in-house modular parametric code has been developed using Python to explore possible modifications to the HET. The effect of increasing the pressure in a passive driver on potential noise reduction is investigated. Optimization of acceleration section length is also explored for conventional drivers. The performance of detonation drivers using H\u2082 and C\u2082H\u2082 fuels with He, Ar, and CO\u2082 diluents is examined.", "date": "2018-06-24", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2018-3566", "id_number": "CaltechAUTHORS:20190816-105723199", "isbn": "978-1-62410-561-6", "book_title": "2018 Aerodynamic Measurement Technology and Ground Testing Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190816-105723199", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-16-1-2503" } ] }, "other_numbering_system": { "items": [ { "id": "2018-3566", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2018-3566", "primary_object": { "basename": "541449.pdf", "url": "https://authors.library.caltech.edu/records/px2m7-dpw83/files/541449.pdf" }, "pub_year": "2018", "author_list": "Lawson, Joel M. and Austin, Joanna M." }, { "id": "https://authors.library.caltech.edu/records/9nsgy-x8g07", "eprint_id": 95709, "eprint_status": "archive", "datestamp": "2023-08-19 09:44:04", "lastmod": "2024-01-14 21:44:46", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Garcia-Suarez-J", "name": { "family": "Garcia-Suarez", "given": "Joaquin" }, "orcid": "0000-0001-8830-4348" }, { "id": "Asimaki-D", "name": { "family": "Asimaki", "given": "Domniki" }, "orcid": "0000-0002-3008-8088" } ] }, "title": "A Quasi-Static Displacement-Based Approximation of Seismic Earth Pressures on Rigid Walls", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2018 American Society of Civil Engineers. \n\nPublished online: June 07, 2018.", "abstract": "A number of linear-elastic solutions have been dedicated to resolve the problem of earth pressures on a rigid wall overlying rigid bedrock, among which, the classic solutions have been provided by Matsuo and Ohara (1960), Wood (1973), and Veletsos and Younan (1994). Wood's solution is mathematically involved (it requires evaluation of a double infinite sum) and the other two involve severe simplifying assumptions. An approximation procedure is presented to develop easy-to-evaluate estimates for the lateral earth thrust on rigid retaining walls under quasi-static loading. The procedure is based on the estimation of soil kinematic variables in the vicinity of the wall, from which strains, stresses, and total thrust are obtained. While the procedure is presented for quasi-static loading of a rigid wall overlaying rigid bedrock, this novel approach could be used to account for other complex effects that have been cumbersome to include in state-of-the art earth pressures procedures, such as dynamic loading, soil non-linear behavior, and wall compliance.", "date": "2018-06-07", "date_type": "published", "publisher": "American Society of Civil Engineers", "place_of_pub": "Reston, VA", "pagerange": "300-311", "id_number": "CaltechAUTHORS:20190522-151131068", "isbn": "9780784481479", "book_title": "Geotechnical Earthquake Engineering and Soil Dynamics V: Numerical Modeling and Soil Structure Interaction", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190522-151131068", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Brandenberg-S-J", "name": { "family": "Brandenberg", "given": "Scott J." } }, { "id": "Manzari-M-T", "name": { "family": "Manzari", "given": "Majid T." } } ] }, "doi": "10.1061/9780784481479.031", "pub_year": "2018", "author_list": "Garcia-Suarez, Joaquin and Asimaki, Domniki" }, { "id": "https://authors.library.caltech.edu/records/p05hy-rjp75", "eprint_id": 91659, "eprint_status": "archive", "datestamp": "2023-08-19 09:37:23", "lastmod": "2023-10-19 23:36:57", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kelzenberg-M-D", "name": { "family": "Kelzenberg", "given": "Michael D." }, "orcid": "0000-0002-6249-2827" }, { "id": "Espinet-Gonz\u00e1lez-P", "name": { "family": "Espinet-Gonz\u00e1lez", "given": "Pilar" }, "orcid": "0000-0002-7656-0077" }, { "id": "Vaidya-N", "name": { "family": "Vaidya", "given": "Nina" } }, { "id": "Warmann-E-C", "name": { "family": "Warmann", "given": "Emily C." }, "orcid": "0000-0002-2810-4608" }, { "id": "Naqavi-A", "name": { "family": "Naqavi", "given": "Ali" } }, { "id": "Loke-S-P", "name": { "family": "Loke", "given": "Samuel P." } }, { "id": "Saive-P", "name": { "family": "Saive", "given": "Philipp" } }, { "id": "Roy-T-A", "name": { "family": "Roy", "given": "Tatiana A." } }, { "id": "Vinogradova-T-G", "name": { "family": "Vinogradova", "given": "Tatiana G." } }, { "id": "Leclerc-C", "name": { "family": "Leclerc", "given": "Christophe" } }, { "id": "Gdoutos-E-E", "name": { "family": "Gdoutos", "given": "Eleftherios E." } }, { "id": "Royer-F", "name": { "family": "Royer", "given": "Fabien" } }, { "id": "Fikes-A-C", "name": { "family": "Fikes", "given": "Austin" } }, { "id": "Bohn-F", "name": { "family": "Bohn", "given": "Florian" } }, { "id": "Abiri-B", "name": { "family": "Abiri", "given": "Behrooz" }, "orcid": "0000-0002-3317-2752" }, { "id": "Hashemi-M-R", "name": { "family": "Hashemi", "given": "Mohammed R." } }, { "id": "Gal-Katziri-M", "name": { "family": "Gal-Katziri", "given": "Matan" }, "orcid": "0000-0001-9100-1188" }, { "id": "Hajimiri-A", "name": { "family": "Hajimiri", "given": "Ali" }, "orcid": "0000-0001-6736-8019" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" }, { "id": "Atwater-H-A", "name": { "family": "Atwater", "given": "Harry A." }, "orcid": "0000-0001-9435-0201" } ] }, "title": "Ultralight Energy Converter Tile for the Space Solar Power Initiative", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2018 IEEE.", "abstract": "We have fabricated a functional prototype of an ultralight power converter tile; a modular building block for a space-based solar power system. The tile is \u223c10\u00d715 cm in area, and weighs \u223c1.5 kg/m^2. It comprises a photovoltaic (PV) solar energy collector, a radio-frequency (RF) power converter, and an array of transmission antennas. The PV collector subassembly utilizes \u223c15x, 1D parabolic trough reflective concentrators with triple-junction (3J) solar cells. It has areal mass of \u223c0.8 kg/m^2, 74% optical efficiency, and a peak specific power of \u223c230W/kg. We demonstrated wireless power transmission over a distance of \u223c50 cm in our lab. Analysis of the sources of mass and inefficiency suggest a path towards achieving dramatically higher performance with future designs.", "date": "2018-06", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "3357-3359", "id_number": "CaltechAUTHORS:20181210-140402265", "isbn": "9781538685297", "book_title": "2018 IEEE 7th World Conference on Photovoltaic Energy Conversion (WCPEC) (A Joint Conference of 45th IEEE PVSC, 28th PVSEC & 34th EU PVSEC)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181210-140402265", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Space-Solar-Power-Project" } ] }, "doi": "10.1109/pvsc.2018.8547403", "pub_year": "2018", "author_list": "Kelzenberg, Michael D.; Espinet-Gonz\u00e1lez, Pilar; et el." }, { "id": "https://authors.library.caltech.edu/records/6snf3-8ft69", "eprint_id": 89429, "eprint_status": "archive", "datestamp": "2023-08-19 09:33:58", "lastmod": "2023-10-18 22:44:41", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Talon-T", "name": { "family": "Talon", "given": "Thibaud" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Shape Measurement of Large Structures in Space: Experiments", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "sun, sensor, shape, reconstruction, measurement, structure, solar, sail, antenna array, laboratory, experiment", "note": "\u00a9 2018 IEEE. \n\nThis research is supported by the Northrop Grumman Corporation and the Space Solar Power Project at Caltech.", "abstract": "A method to reconstruct the shape of a large planar structure in space is introduced and demonstrated through a lab-scale experiment. Lightweight sun sensors are distributed on the structure to measure local angles relative to the sun. The methodology to integrate the measured angles into the shape of the structure, based on a decomposition of the shape into basis functions is introduced. This methodology has been implemented on a lab-scale experiment. The design of the sensors is based on a 4 pixel pinhole camera. The calibration method for these sensors is presented as well as the techniques to integrate and communicate with them. A 1.2 m by 20 cm structure was designed and populated with sensors to show the performance of an integrated system. Preliminary results show an accuracy of 1 mm RMS on the shape reconstruction of this structure.", "date": "2018-06", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "581-584", "id_number": "CaltechAUTHORS:20180906-143935251", "isbn": "978-1-5386-2474-6", "book_title": "2018 5th IEEE International Workshop on Metrology for AeroSpace (MetroAeroSpace)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180906-143935251", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Northrop Grumman Corporation" }, { "agency": "Space Solar Power Project" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Space-Solar-Power-Project" } ] }, "doi": "10.1109/MetroAeroSpace.2018.8453578", "pub_year": "2018", "author_list": "Talon, Thibaud and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/7vqmh-f9102", "eprint_id": 92004, "eprint_status": "archive", "datestamp": "2023-08-19 09:21:08", "lastmod": "2024-01-14 21:23:45", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Muslimov-E-R", "name": { "family": "Muslimov", "given": "Eduard" } }, { "id": "Hugot-E", "name": { "family": "Hugot", "given": "Emmanuel" }, "orcid": "0000-0002-5879-6318" }, { "id": "Lombardo-S", "name": { "family": "Lombardo", "given": "Simona" }, "orcid": "0000-0002-2161-8104" }, { "id": "Roulet-M", "name": { "family": "Roulet", "given": "Melanie" } }, { "id": "Behaghel-T", "name": { "family": "Behaghel", "given": "Thibault" } }, { "id": "Ferrari-M", "name": { "family": "Ferrari", "given": "Marc" } }, { "id": "Jahn-W", "name": { "family": "Jahn", "given": "Wilfried" } }, { "id": "Gaschet-C", "name": { "family": "Gaschet", "given": "Christophe" } }, { "id": "Chambion-B", "name": { "family": "Chambion", "given": "Bertrand" } }, { "id": "Henry-M-D", "name": { "family": "Henry", "given": "David" }, "orcid": "0000-0002-5201-0644" } ] }, "title": "Curved detectors for wide field imaging systems: impact on tolerance analysis", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2018 Society of Photo-Optical Instrumentation Engineers (SPIE). \n\nThe authors acknowledge the support of the European Research council through the H2020 - ERC-STG-2015 \u2013 678777 ICARUS program. This research was partially supported by the HARMONI instrument consortium. We also would like to thank Pierre Baron from Altechna Company for fruitful discussions, which helped us to state the aim of this study.\n\nPublished - 106790W.pdf
", "abstract": "In the present paper we consider quantitative estimation of the tolerances widening in optical systems with curved detectors. The gain in image quality allows to loosen the margins for manufacturing and assembling errors. On another hand, the requirements for the detector shape and positioning become more tight. We demonstrate both of the effects on example of two optical designs. The first one is a rotationally-symmetrical lens with focal length of 25 mm, f-ratio of 3.5 and field of view equal to 72\u00b0, working in the visible domain. The second design is a three-mirror anastigmat telescope with focal length of 250 mm, f-ratio of 2.0 and field of view equal to 4\u00b0x4\u00b0. In both of the cases use of curved detectors allow to increase the image quality and substantially decrease the requirements for manufacturing precision.", "date": "2018-05-24", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "Art. No. 106790W", "id_number": "CaltechAUTHORS:20190102-155138231", "isbn": "9781510618848", "book_title": "Optics, Photonics, and Digital Technologies for Imaging Applications V", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190102-155138231", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "European Research Council (ERC)", "grant_number": "678777" }, { "agency": "HARMONI instrument consortium" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Schelkens-P", "name": { "family": "Schelkens", "given": "Peter" } }, { "id": "Ebrahami-T", "name": { "family": "Ebrahami", "given": "Touradj" } }, { "id": "Crist\u00f3bal-G", "name": { "family": "Crist\u00f3bal", "given": "Gebriel" } } ] }, "doi": "10.1117/12.2305923", "primary_object": { "basename": "106790W.pdf", "url": "https://authors.library.caltech.edu/records/7vqmh-f9102/files/106790W.pdf" }, "pub_year": "2018", "author_list": "Muslimov, Eduard; Hugot, Emmanuel; et el." }, { "id": "https://authors.library.caltech.edu/records/2zt67-fdc15", "eprint_id": 87159, "eprint_status": "archive", "datestamp": "2023-08-19 08:25:09", "lastmod": "2024-01-14 20:15:02", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Wei-Yuchen", "name": { "family": "Wei", "given": "Yuchen" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Phenomenological model for coupled multi-axial piezoelectricity", "ispublished": "unpub", "full_text_status": "public", "keywords": "Ferroelectrics, phenomenological model, parameter calibration, electro-mechanical coupling", "note": "\u00a9 2018 Society of Photo-Optical Instrumentation Engineers (SPIE). \n\nThe authors acknowledge helpful discussions with Professor Robert McMeeking and Professor Christopher Lynch.\n\nPublished - 105960R.pdf
", "abstract": "A quantitative calibration of an existing phenomenological model for polycrystalline ferroelectric ceramics is presented. The model relies on remnant strain and polarization as independent variables. Innovative experimental and numerical model identification procedures are developed for the characterization of the coupled electro-mechanical, multi-axial nonlinear constitutive law. Experiments were conducted on thin PZT-5A4E plates subjected to cross-thickness electric field. Unimorph structures with different thickness ratios between PZT-5A4E plate and substrate were tested, to subject the piezo plates to coupled electro-mechanical fields. Material state histories in electric field-strain-polarization space and stress-strain-polarization space were recorded. An optimization procedure is employed for the determination of the model parameters, and the calibrated constitutive law predicts both the uncoupled and coupled experimental observations accurately.", "date": "2018-03-22", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "Art. No. 105960R", "id_number": "CaltechAUTHORS:20180615-113248296", "isbn": "9781510616882", "book_title": "Behavior and Mechanics of Multifunctional Materials and Composites XII", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180615-113248296", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Naguib-H-E", "name": { "family": "Naguib", "given": "Hani E." } } ] }, "doi": "10.1117/12.2296346", "primary_object": { "basename": "105960R.pdf", "url": "https://authors.library.caltech.edu/records/2zt67-fdc15/files/105960R.pdf" }, "pub_year": "2018", "author_list": "Wei, Yuchen and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/z36ae-22p78", "eprint_id": 87160, "eprint_status": "archive", "datestamp": "2023-08-19 07:55:47", "lastmod": "2024-01-14 20:15:05", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Scorticati-D", "name": { "family": "Scorticati", "given": "Davide" } }, { "id": "Crapella-G", "name": { "family": "Crapella", "given": "Giacomo" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Fast and broadband detector for laser radiation", "ispublished": "unpub", "full_text_status": "public", "keywords": "Fast, Broadband, Thermal, Detector, Laser, LITV", "note": "\u00a9 2018 Society of Photo-Optical Instrumentation Engineers (SPIE).\n\nPublished - 105390I.pdf
", "abstract": "We developed a fast detector (patent pending) based on the Laser Induced Transverse Voltage (LITV) effect. The advantage of detectors using the LITV effect over pyroelectric sensors and photodiodes for laser radiation measurements is the combination of an overall fast response time, broadband spectral acceptance, high saturation threshold to direct laser irradiation and the possibility to measure pulsed as well as cw-laser sources. \n\nThe detector is capable of measuring the energy of single laser pulses with repetition frequencies up to the MHz range, adding the possibility to also measure the output power of cw-lasers. \n\nMoreover, the thermal nature of the sensor enables the capability to work in a broadband spectrum, from UV to THz as well as the possibility of operating in a broad-range (10^(-3)-10^2 W/cm^2 ) of incident average optical power densities of the laser radiation, without the need of adopting optical filters nor other precautions.", "date": "2018-02-22", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "Art. No. 105390I", "id_number": "CaltechAUTHORS:20180615-114153851", "isbn": "9781510615632", "book_title": "Photonic Instrumentation Engineering V", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180615-114153851", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Soskind-Y-G", "name": { "family": "Soskind", "given": "Yakov G." } } ] }, "doi": "10.1117/12.2294002", "primary_object": { "basename": "105390I.pdf", "url": "https://authors.library.caltech.edu/records/z36ae-22p78/files/105390I.pdf" }, "pub_year": "2018", "author_list": "Scorticati, Davide; Crapella, Giacomo; et el." }, { "id": "https://authors.library.caltech.edu/records/nbr40-fvc51", "eprint_id": 97657, "eprint_status": "archive", "datestamp": "2023-08-19 07:20:06", "lastmod": "2023-10-18 16:11:04", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Royer-F", "name": { "family": "Royer", "given": "Fabien" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Ultralight Ladder-type Coilable Space Structures", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2018 American Institute of Aeronautics and Astronautics. \n\nFinancial support from the Northrop Grumman Corporation is gratefully acknowledged.\n\nAccepted Version - Royer_and_Pellegrino_2018.pdf
", "abstract": "We describe the concept of an ultralight ladder-type coilable strip used as the main element to build large planar deployable space solar power spacecrafts. It is composed of TRAC longerons connected with lenticular cross-section rods which enables it to fully flatten and thus be packaged efficiently. The design is tackled here as well as the manufacturing of a scaled version of this new type of structures. Finite element analyses are used to understand the underlying behavior of such structures. Experimental model testing is then used as a way of validating this computational framework. Finally a simulation framework enabling simulation at the spacecraft scale is presented and preliminary results obtained with shows how such structures behave while integrated into a larger spacecraft.", "date": "2018-01-08", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2018-1200", "id_number": "CaltechAUTHORS:20190805-134838873", "isbn": "9781624105302", "book_title": "2018 AIAA Scitech Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190805-134838873", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Northrop Grumman Corporation" } ] }, "other_numbering_system": { "items": [ { "id": "2018-1200", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Space-Solar-Power-Project" } ] }, "doi": "10.2514/6.2018-1200", "primary_object": { "basename": "Royer_and_Pellegrino_2018.pdf", "url": "https://authors.library.caltech.edu/records/nbr40-fvc51/files/Royer_and_Pellegrino_2018.pdf" }, "pub_year": "2018", "author_list": "Royer, Fabien and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/4afjx-yfv11", "eprint_id": 97643, "eprint_status": "archive", "datestamp": "2023-08-19 07:20:01", "lastmod": "2023-10-18 16:10:23", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Gdoutos-E-E", "name": { "family": "Gdoutos", "given": "Eleftherios E." } }, { "id": "Leclerc-C", "name": { "family": "Leclerc", "given": "Christophe" } }, { "id": "Royer-F", "name": { "family": "Royer", "given": "Fabien" } }, { "id": "Kelzenberg-M-D", "name": { "family": "Kelzenberg", "given": "Michael D." }, "orcid": "0000-0002-6249-2827" }, { "id": "Warmann-E-C", "name": { "family": "Warmann", "given": "Emily C." }, "orcid": "0000-0002-2810-4608" }, { "id": "Espinet-Gonz\u00e1lez-P", "name": { "family": "Espinet-Gonz\u00e1lez", "given": "Pilar" }, "orcid": "0000-0002-7656-0077" }, { "id": "Vaidya-N", "name": { "family": "Vaidya", "given": "Nina" } }, { "id": "Bohn-F", "name": { "family": "Bohn", "given": "Florian" } }, { "id": "Abiri-B", "name": { "family": "Abiri", "given": "Behrooz" }, "orcid": "0000-0002-3317-2752" }, { "id": "Hashemi-M-R", "name": { "family": "Hashemi", "given": "Mohammed R." } }, { "id": "Gal-Katziri-M", "name": { "family": "Gal-Katziri", "given": "Matan" }, "orcid": "0000-0001-9100-1188" }, { "id": "Fikes-A-C", "name": { "family": "Fikes", "given": "Austin" } }, { "id": "Atwater-H-A", "name": { "family": "Atwater", "given": "Harry A." }, "orcid": "0000-0001-9435-0201" }, { "id": "Hajimiri-A", "name": { "family": "Hajimiri", "given": "Ali" }, "orcid": "0000-0001-6736-8019" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "A lightweight tile structure integrating photovoltaic conversion and RF power transfer for space solar power applications", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2018 American Institute of Aeronautics and Astronautics. \n\nFinancial support from the Northrop Grumman Corporation is gratefully acknowledged.\n\nAccepted Version - Gdoutos_et_al_2018.pdf
", "abstract": "We demonstrate the development of a prototype lightweight (1.5 kg/m^3) tile structure capable of photovoltaic solar power capture, conversion to radio frequency power, and transmission through antennas. This modular tile can be repeated over an arbitrary area to forma large aperture which could be placed in orbit to collect sunlight and transmit electricity to any location. Prototype design is described and validated through finite element analysis, and high-precision ultra-light component manufacture and robust assembly are described.", "date": "2018-01-08", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2018-2202", "id_number": "CaltechAUTHORS:20190805-134837271", "isbn": "9781624105302", "book_title": "AIAA Scitech 2018 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190805-134837271", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Northrop Grumman Corporation" } ] }, "other_numbering_system": { "items": [ { "id": "2018-2202", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Space-Solar-Power-Project" } ] }, "doi": "10.2514/6.2018-2202", "primary_object": { "basename": "Gdoutos_et_al_2018.pdf", "url": "https://authors.library.caltech.edu/records/4afjx-yfv11/files/Gdoutos_et_al_2018.pdf" }, "pub_year": "2018", "author_list": "Gdoutos, Eleftherios E.; Leclerc, Christophe; et el." }, { "id": "https://authors.library.caltech.edu/records/rbm1k-p9p24", "eprint_id": 97963, "eprint_status": "archive", "datestamp": "2023-08-19 07:20:11", "lastmod": "2023-10-18 16:55:07", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Leclerc-C", "name": { "family": "Leclerc", "given": "Christophe" } }, { "id": "Pedivellano-A", "name": { "family": "Pedivellano", "given": "Antonio" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Stress Concentration and Material Failure During Coiling of Ultra-Thin TRAC Booms", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2018 American Institute of Aeronautics and Astronautics. \n\nThe authors acknowledge financial support from the Northrop Grumman Corporation, the Natural Sciences and Engineering Research Council of Canada and the Keck Institute for Space Studies.\n\nAccepted Version - Leclerc_Pedivellano_Pellegrino2018.pdf
", "abstract": "Ultra-thin TRAC booms are a promising technology for large deployable structures for space applications. A manufacturing process producing composites TRAC booms with flange thickness as low as 53 \u03bcm is proposed. Coiling behavior around hub with radii ranging from 19.1 mm to 31.8 mm is studied both experimentally and through finite element simulations. Due to the thinness of the TRAC boom, a buckle appears in the inner flange, in the transition region from the fully deployed to the coiled configurations. Material failure is observed at this location, and this correlates well with stresses computed in simulation, coupled with the fiber microbuckling failure criterion. Reducing the thickness, either by changing the laminate or by improving the manufacturing process, is shown to reduce stresses, allowing coiling around smaller hubs without material failure.", "date": "2018-01-08", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2018-0690", "id_number": "CaltechAUTHORS:20190816-144340271", "isbn": "9781624105302", "book_title": "2018 AIAA Spacecraft Structures Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190816-144340271", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Northrop Grumman Corporation" }, { "agency": "Natural Sciences and Engineering Research Council of Canada (NSERC)" }, { "agency": "Keck Institute for Space Studies (KISS)" } ] }, "other_numbering_system": { "items": [ { "id": "2018-0690", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Keck-Institute-for-Space-Studies" }, { "id": "Space-Solar-Power-Project" } ] }, "doi": "10.2514/6.2018-0690", "primary_object": { "basename": "Leclerc_Pedivellano_Pellegrino2018.pdf", "url": "https://authors.library.caltech.edu/records/rbm1k-p9p24/files/Leclerc_Pedivellano_Pellegrino2018.pdf" }, "pub_year": "2018", "author_list": "Leclerc, Christophe; Pedivellano, Antonio; et el." }, { "id": "https://authors.library.caltech.edu/records/1kfpb-bg361", "eprint_id": 97972, "eprint_status": "archive", "datestamp": "2023-08-19 07:20:24", "lastmod": "2023-10-18 16:55:42", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Leibowitz-M-G", "name": { "family": "Leibowitz", "given": "Matthew G." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "Joanna M." }, "orcid": "0000-0003-3129-5035" } ] }, "title": "Assessment of Reflected Shock Tunnels for Mars Entry Vehicle Ground Testing", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2018 American Institute of Aeronautics and Astronautics.", "abstract": "Recent carbon dioxide studies in reflected shock tunnel testing have noted discrepancies in the shock shapes between experiments and simulations. These have been attributed to freezing vibrational modes unaccounted for in the simulations during the rapid expansion through the nozzle. This study focuses on blunt body CO_2 experiments and simulations in the T5 Reflected Shock Tunnel to examine possible sources of error when making standoff distance and heat flux measurements. The effect of increasing the nozzle area ration to further expand the flow in the nozzle is examined and a method for making consistent standoff distance comparisons from experiments and simulations is developed. Finally, experiments and simulations are compared to theoretical models.", "date": "2018-01-08", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2018-1721", "id_number": "CaltechAUTHORS:20190816-144341084", "isbn": "9781624105241", "book_title": "AIAA Scitech 2018 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190816-144341084", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2018-1721", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2018-1721", "pub_year": "2018", "author_list": "Leibowitz, Matthew G. and Austin, Joanna M." }, { "id": "https://authors.library.caltech.edu/records/3hnnz-x3a61", "eprint_id": 97675, "eprint_status": "archive", "datestamp": "2023-08-19 07:12:44", "lastmod": "2023-10-20 21:49:27", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bosia-F", "name": { "family": "Bosia", "given": "Federico" }, "orcid": "0000-0002-2886-4519" }, { "id": "Schlothauer-A", "name": { "family": "Schlothauer", "given": "Arthur" } }, { "id": "Leclerc-C", "name": { "family": "Leclerc", "given": "Christophe" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Cure-induced deformation of ultra-thin composite laminates", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2018 American Institute of Aeronautics and Astronautics. \n\nFinancial support from the Northrop Grumman Corporation is gratefully acknowledged. DSC experiments were performed in the Kornfield Lab at the California Institute of Technology: we thank Dr. T. Di Luccio and Mr. K. Ramachandran for helpful comments and discussions. The manufacturing and measurements of composite laminates were carried out at the Space Structure Laboratory at the California Institute\nof Technology. Numerical simulations were performed using COMPRO simulation software package for Abaqus, developed by Convergent Manufacturing Technologies.\n\nAccepted Version - Scitech2018_Bosi_Pellegrino_REVISED.pdf
", "abstract": "In fiber reinforced composite materials, the manufacturing process induces residual stresses and distortions that decrease the mechanical performance of the structure and affect its geometry, especially in thin laminates. Multi-physics simulations were performed to assess the spring-in effect in ultra-thin composite parabolic solar reflectors. For this purpose, a resin kinetic model has been developed by means of differential scanning calorimetry experiments. The kinetic relation has been implemented into the finite element software in order to correctly predict the evolution of the composite degree of cure during the manufacturing process. Specimens were produced in an autoclave and their final geometries were measured by means of a non-contact measuring system and compared with numerical predictions, showing very good agreement.", "date": "2018-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2018-2241", "id_number": "CaltechAUTHORS:20190806-133219697", "isbn": "978-1-62410-532-6", "book_title": "AIAA Scitech 2018 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190806-133219697", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Northrop Grumman Corporation" } ] }, "other_numbering_system": { "items": [ { "id": "2018-2241", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Space-Solar-Power-Project" } ] }, "doi": "10.2514/6.2018-2241", "primary_object": { "basename": "Scitech2018_Bosi_Pellegrino_REVISED.pdf", "url": "https://authors.library.caltech.edu/records/3hnnz-x3a61/files/Scitech2018_Bosi_Pellegrino_REVISED.pdf" }, "pub_year": "2018", "author_list": "Bosia, Federico; Schlothauer, Arthur; et el." }, { "id": "https://authors.library.caltech.edu/records/z1x82-pdr59", "eprint_id": 97658, "eprint_status": "archive", "datestamp": "2023-08-19 07:12:39", "lastmod": "2023-10-18 16:11:07", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ferraro-S", "name": { "family": "Ferraro", "given": "S." } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "S." }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Self-Deployable Joints for Ultra-Light Space Structures", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2018 American Institute of Aeronautics and Astronautics. \n\nThis work was supported by a NASA Space Technology Research Fellowship. S.F. would like to acknowledge Dr. William Doggett, NASA Langley, for mentoring and providing invaluable technical and scientific support.\n\nAccepted Version - ferraro2018.pdf
", "abstract": "The paper presents ongoing research and development of novel concepts for deployable space structures using self-latching, flexural joints to replace mechanical hinges. The mechanics of deformation of Fiber-Reinforced-Polymers (FRP) joints for in-plane deployment mechanisms are studied. Methods for characterizing these joints via experiments and numerical simulations are proposed. A failure criterion suitable for ultra-thin, plain-weave composites is used to predict failure of the joints and achieve a successful design.", "date": "2018-01", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2018-0694", "id_number": "CaltechAUTHORS:20190805-134838958", "isbn": "9781624105302", "book_title": "AIAA Scitech 2018 Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190805-134838958", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA Space Technology Research Fellowship" } ] }, "other_numbering_system": { "items": [ { "id": "2018-0694", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2018-0694", "primary_object": { "basename": "ferraro2018.pdf", "url": "https://authors.library.caltech.edu/records/z1x82-pdr59/files/ferraro2018.pdf" }, "pub_year": "2018", "author_list": "Ferraro, S. and Pellegrino, S." }, { "id": "https://authors.library.caltech.edu/records/tztj2-cj848", "eprint_id": 82987, "eprint_status": "archive", "datestamp": "2023-08-21 22:10:01", "lastmod": "2023-10-17 22:49:55", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Mac-Donald-K", "name": { "family": "Mac Donald", "given": "Kimberley" } }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "Guruswami" }, "orcid": "0000-0002-2912-0001" } ] }, "title": "Towards Measuring Intergranular Force Transmission Using Confocal Microscopy and Digital Volume Correlation", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Confocal microscopy; Digital Volume Correlation (DVC); Granular mechanics; Intergranular forces; Shear bands", "note": "\u00a9 2018 The Society for Experimental Mechanics, Inc. \n\nFirst Online: 04 November 2017. \n\nThe project depicted is sponsored by the Department of the Defense, Defense Threat Reduction Agency (HDTRA1-12-0041). The content of the information does not necessarily reflect the position or the policy of the federal government, and no official endorsement should be inferred. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE-1144469. Imaging was performed in the Biological Imaging Facility, with the support of the Caltech Beckman Institute and the Arnold and Mabel Beckman Foundation.", "abstract": "We aim to show the feasibility of using confocal microscopy imaging techniques for Digital Volume Correlation (DVC) and analysis of granular mechanics experiments. The first part of this study validates the DVC and confocal microscopy imaging methods for a general problem of uniaxial compression of continuous media. The second part investigates the specific problem of granular mechanics. Intergranular force transmission will be analyzed from 3D image stacks captured using confocal microscopy. DVC methods will be used to analyze the full 3D grain motions and deformations. The intergranular forces will be determined inversely using the Granular Element Method (GEM). Preliminarily results show that confocal microscopy is a useful volumetric imaging method for DVC analyses and shows promise in furthering the study of intergranular force chains and shear bands.", "date": "2017-11-04", "date_type": "published", "publisher": "Springer", "place_of_pub": "Cham, Switzerland", "pagerange": "85-88", "id_number": "CaltechAUTHORS:20171106-135543296", "isbn": "978-3-319-63027-4", "book_title": "Advancement of Optical Methods in Experimental Mechanics", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171106-135543296", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Defense Threat Reduction Agency (DTRA)", "grant_number": "HDTRA1-12-0041" }, { "agency": "NSF Graduate Research Fellowship", "grant_number": "DGE-1144469" }, { "agency": "Caltech Beckman Institute" }, { "agency": "Arnold and Mabel Beckman Foundation" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Lamberti-L", "name": { "family": "Lamberti", "given": "L." } }, { "id": "Lin-M-T", "name": { "family": "Lin", "given": "M. T." } }, { "id": "Furlong-C", "name": { "family": "Furlong", "given": "C." } }, { "id": "Sciammarella-C", "name": { "family": "Sciammarella", "given": "C." } } ] }, "doi": "10.1007/978-3-319-63028-1_13", "pub_year": "2017", "author_list": "Mac Donald, Kimberley and Ravichandran, Guruswami" }, { "id": "https://authors.library.caltech.edu/records/k0ms6-ffs72", "eprint_id": 85935, "eprint_status": "archive", "datestamp": "2023-08-19 05:51:52", "lastmod": "2023-10-18 19:06:55", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Sun-Xingsheng", "name": { "family": "Sun", "given": "Xingsheng" } }, { "id": "Ariza-P", "name": { "family": "Ariza", "given": "Pilar" }, "orcid": "0000-0003-0266-0216" }, { "id": "Ortiz-M", "name": { "family": "Ortiz", "given": "Michael" }, "orcid": "0000-0001-5877-4824" }, { "id": "Wang-Kevin-G", "name": { "family": "Wang", "given": "Kevin G." } } ] }, "title": "Atomistic Simulation of Hydrogen Diffusion in Palladium Nanoparticles Using a Diffusive Molecular Dynamics Method", "ispublished": "unpub", "full_text_status": "public", "keywords": "Diffusion (Physics), Simulation, Nanoparticles, Hydrogen, Molecular dynamics methods, Palladium", "note": "\u00a9 2017 by ASME. \n\nPaper No. IMECE2017-71400.", "abstract": "Understanding the transport of hydrogen within metals is crucial for the advancement of energy storage and the mitigation of hydrogen embrittlement. Using nanosized palladium particles as a model, recent experimental studies have revealed several highly nonlinear phenomena that occur over a long period of time. The time scale of these phenomena is beyond the capability of established atomistic models. In this work, we present the application of a new model, referred to as diffusive molecular dynamics (DMD), to simulating long-term diffusive mass transport at atomistic length scale. Specifically, we validate the model for the long-term dynamics of a single hydrogen atom on palladium lattice. We show that the DMD result is in satisfactory agreement with the result of the classical random walk model. Then, we apply the DMD model to simulate the absorption of hydrogen by a palladium nanocube with an edge length of 16 nm. We show that the absorption process is dominated by the propagation of a sharp, coherent \u03b1/\u03b2 hydride phase boundary. We also characterize the local lattice deformation near the dynamic phase boundary using the mean positions of the palladium and hydrogen atoms.", "date": "2017-11", "date_type": "published", "publisher": "American Society of Mechanical Engineers", "place_of_pub": "New York, NY", "pagerange": "Art. No. V009T12A026", "id_number": "CaltechAUTHORS:20180418-093213482", "isbn": "978-0-7918-5844-8", "book_title": "Mechanics of Solids, Structures and Fluids; NDE, Structural Health Monitoring and Prognosis", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180418-093213482", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1115/IMECE2017-71400", "pub_year": "2017", "author_list": "Sun, Xingsheng; Ariza, Pilar; et el." }, { "id": "https://authors.library.caltech.edu/records/qe0da-6nc51", "eprint_id": 81377, "eprint_status": "archive", "datestamp": "2023-08-19 05:04:48", "lastmod": "2024-01-14 05:27:44", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kirchdoerfer-T", "name": { "family": "Kirchdoerfer", "given": "Trenton" } }, { "id": "Ortiz-M", "name": { "family": "Ortiz", "given": "Michael" }, "orcid": "0000-0001-5877-4824" } ] }, "title": "Data-Driven Computing", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2018 Springer International Publishing AG. \n\nFirst Online: 10 September 2017.", "abstract": "Data-Driven Computing is a new field of computational analysis which uses provided data to directly produce predictive outcomes. Recent works in this developing field have established important properties of Data-Driven solvers, accommodated noisy data sets and demonstrated both quasi-static and dynamic solutions within mechanics. This work reviews this initial progress and advances some of the many possible improvements and applications that might best advance the field. Possible method improvements discuss incorporation of data quality metrics, and adaptive data additions while new applications focus on multi-scale analysis and the need for public databases to support constitutive data collaboration.", "date": "2017-09-10", "date_type": "published", "publisher": "Springer", "place_of_pub": "Cham, Switzerland", "pagerange": "165-183", "id_number": "CaltechAUTHORS:20170912-142917371", "isbn": "978-3-319-60884-6", "book_title": "Advances in Computational Plasticity: A Book in Honour of D. Roger J. Owen", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170912-142917371", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "O\u00f1ate-E", "name": { "family": "O\u00f1ate", "given": "Eugenio" } }, { "id": "Peric-D", "name": { "family": "Peric", "given": "Djordje" } }, { "id": "de-Souza-Neto-E", "name": { "family": "de Souza Neto", "given": "Eduardo" } }, { "id": "Chiumenti-M", "name": { "family": "Chiumenti", "given": "Michele" } } ] }, "doi": "10.1007/978-3-319-60885-3_8", "pub_year": "2017", "author_list": "Kirchdoerfer, Trenton and Ortiz, Michael" }, { "id": "https://authors.library.caltech.edu/records/0a5rn-vrd10", "eprint_id": 87978, "eprint_status": "archive", "datestamp": "2023-08-19 05:02:48", "lastmod": "2024-01-14 20:28:09", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lillie-C-F", "name": { "family": "Lillie", "given": "Charles F." } }, { "id": "MacEwen-H-A", "name": { "family": "MacEwen", "given": "Howard A." } }, { "id": "Polidan-R-S", "name": { "family": "Polidan", "given": "Ronald S." } }, { "id": "Breckinridge-J-B", "name": { "family": "Breckinridge", "given": "James B." }, "orcid": "0000-0002-9488-098X" } ] }, "title": "A 4-m evolvable space telescope configured for NASA's HabEx Mission: the initial stage of LUVOIR", "ispublished": "unpub", "full_text_status": "public", "keywords": "Space telescope, coronagraph, exoplanets, on-orbit assembly, servicing, infrastructure, robotics", "note": "\u00a9 2017 Society of Photo-Optical Instrumentation Engineers (SPIE). \n\nOur Evolvable Space Telescope (EST) study was initiated by Northrop Grumman Aerospace Systems in Redondo Beach, California and funded with Internal Research and Development (IRAD) funds from March 2014 through January 20016. Since that date the authors have continued to refine the EST concept using funding from their personal owned organizations. We thank John Mather, Marc Postman, Harley Thronson, Gary Mathews, Mark Clampin, Lee Feinberg, Jeremy Kasdin, Tony Hull, and my others for useful discussions during this study.\n\nPublished - 103980R.pdf
", "abstract": "Previous papers have described our concept for a large telescope that would be assembled in space in several stages (in different configurations) over a period of fifteen to 20 years. Spreading the telescope development, launch and operations cost over 20 years would minimize the impact on NASA's annual budget and drastically shorten the time between program start and \"first light\" for this space observatory. The first Stage of this Evolvable Space Telescope (EST) would consist of an instrument module located at the prime focus of three 4-meter hexagonal mirrors arranged in a semi-circle to form one-half of a 12-m segmented mirror. After several years three additional 4-m mirrors would be added to create a 12-m filled aperture. Later, twelve more 4-m mirrors will be added to this Stage 2 telescope to create a 20-m filled aperture space telescope. At each stage the telescope would have an unparalleled capability for UVOIR observations, and the results of these observations will guide the evolution of the telescope and its instruments. In this paper we describe our design concept for an initial configuration of our Evolvable Space Telescope that can meet the requirements of the 4-m version of the HabEx spacecraft currently under consideration by NASA's Habitable Exoplanet Science and Technology Definition Team. This \"Stage Zero\" configuration will have only one 4-m mirror segment with the same 30-m focal length and a prime focus coronagraph with normal incidence optics to minimize polarization effects. After assembly and checkout in cis-lunar space, the telescope would transfer to a Sun-Earth L2 halo orbit and obtain high sensitivity, high resolution, high contrast UVOIR observations that address the scientific objectives of the Habitable-Exoplanet Imaging Missions.", "date": "2017-09-05", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "Art. no. 103980R", "id_number": "CaltechAUTHORS:20180718-154558929", "isbn": "9781510612532", "book_title": "UV/Optical/IR Space Telescopes and Instruments: Innovative Technologies and Concepts VIII", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180718-154558929", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Northrop Grumman Corporation" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "MacEwen-H-A", "name": { "family": "MacEwen", "given": "Harold A." } }, { "id": "Breckinridge-J-B", "name": { "family": "Breckinridge", "given": "James B." } } ] }, "doi": "10.1117/12.2274623", "primary_object": { "basename": "103980R.pdf", "url": "https://authors.library.caltech.edu/records/0a5rn-vrd10/files/103980R.pdf" }, "pub_year": "2017", "author_list": "Lillie, Charles F.; MacEwen, Howard A.; et el." }, { "id": "https://authors.library.caltech.edu/records/gnwhy-v4h70", "eprint_id": 99818, "eprint_status": "archive", "datestamp": "2023-08-19 04:59:04", "lastmod": "2023-10-18 18:50:06", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Leclerc-C", "name": { "family": "Leclerc", "given": "Christophe" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Ultra-Thin Composite Deployable Booms", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2017 HafenCity University Hamburg & International Association of Shell & Spatial Structures (IASS).", "abstract": "Ultra-thin TRAC booms have many applications for spacecraft structures due to their very efficient packaging. A manufacturing process is proposed for composite TRAC booms with a total flange thickness of 71 \u03bcm. The mechanical behavior in both bending and torsion is studied through experiments.", "date": "2017-09", "date_type": "published", "publisher": "HafenCity University", "id_number": "CaltechAUTHORS:20191112-155802266", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191112-155802266", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Space-Solar-Power-Project" }, { "id": "GALCIT" } ] }, "pub_year": "2017", "author_list": "Leclerc, Christophe and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/x02zq-w8133", "eprint_id": 83924, "eprint_status": "archive", "datestamp": "2023-08-19 04:56:12", "lastmod": "2023-10-18 14:31:11", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bandyopadhyay-S", "name": { "family": "Bandyopadhyay", "given": "Saptarshi" } }, { "id": "Baldini-F", "name": { "family": "Baldini", "given": "Francesca" } }, { "id": "Foust-Rebecca", "name": { "family": "Foust", "given": "Rebecca" }, "orcid": "0000-0003-1470-1716" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Rahmani-A", "name": { "family": "Rahmani", "given": "Amir" } }, { "id": "de-la-Croix-Jean-Pierre", "name": { "family": "de la Croix", "given": "Jean-Pierre" } }, { "id": "Hadaegh-F-Y", "name": { "family": "Hadaegh", "given": "Fred Y." } } ] }, "title": "Distributed Spatiotemporal Motion Planning for Spacecraft Swarms in Cluttered Environments", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2017 by the American Institute of Aeronautics and Astronautics, Inc. \n\nThis work was supported by the Jet Propulsion Laboratory's Research and Technology Development (R&TD) program. Part of the research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. \u00a9 2017 California Institute of Technology. Government sponsorship acknowledged.\n\nPublished - 6.2017-5323.pdf
", "abstract": "This paper focuses on trajectory planning for spacecraft swarms in cluttered environments, like debris fields or the asteroid belt. Our objective is to reconfigure the spacecraft swarm to a desired formation in a distributed manner while minimizing fuel and avoiding collisions among themselves and with the obstacles. In our prior work we proposed a novel distributed guidance algorithm for spacecraft swarms in static environments. In this paper, we present the Multi-Agent Moving-Obstacles Spherical Expansion and Sequential Convex Programming (MAMO SE-SCP) algorithm that extends our prior work to include spatiotemporal constraints such as time-varying, moving obstacles and desired time-varying terminal positions. In the MAMO SE-SCP algorithm, each agent uses a spherical-expansion-based sampling algorithm to cooperatively explore the time-varying environment, a distributed assignment algorithm to agree on the terminal position for each agent, and a sequential-convex-programming-based optimization step to compute the locally-optimal trajectories from the current location to the assigned time-varying terminal\nposition while avoiding collision with other agent and the moving obstacles. Simulations results demonstrate that the proposed distributed algorithm can be used by a spacecraft\nswarm to achieve a time-varying, desired formation around an object of interest in a dynamic environment with many moving and tumbling obstacles.", "date": "2017-09", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "pagerange": "Art. No. 2017-5323", "id_number": "CaltechAUTHORS:20171214-123928298", "isbn": "978-1-62410-483-1", "book_title": "AIAA SPACE and Astronautics Forum and Exposition", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171214-123928298", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "JPL Research and Technology Development Program" }, { "agency": "NASA/JPL/Caltech" } ] }, "other_numbering_system": { "items": [ { "id": "2017-5323", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2017-5323", "primary_object": { "basename": "6.2017-5323.pdf", "url": "https://authors.library.caltech.edu/records/x02zq-w8133/files/6.2017-5323.pdf" }, "pub_year": "2017", "author_list": "Bandyopadhyay, Saptarshi; Baldini, Francesca; et el." }, { "id": "https://authors.library.caltech.edu/records/2db4w-zg518", "eprint_id": 99856, "eprint_status": "archive", "datestamp": "2023-08-19 04:59:08", "lastmod": "2023-10-18 18:52:11", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bessa-M-A", "name": { "family": "Bessa", "given": "Miguel A." } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Design of ultra-thin composite deployable shell structures through machine learning", "ispublished": "unpub", "full_text_status": "public", "keywords": "Buckling, ultra-thin composite shells, machine learning, data mining, data-driven computational framework, design", "note": "\u00a9 2017 by Miguel A. Bessa and Sergio Pellegrino. Published by the International Association for Shell and Spatial Structures (IASS) with permission. \n\nThe authors acknowledge financial support from the Northrop Grumman Corporation. Comments of an anonymous reviewer are gratefully acknowledged.\n\nPublished - MABessa_IASS17_MachineLearning_article_final.pdf
", "abstract": "A data-driven computational framework is applied for the design of optimal ultra-thin Triangular Rollable and Collapsible (TRAC) carbon fiber booms. High-fidelity computational analyses of a large number of geometries are used to build a database. This database is then analyzed by machine learning to construct design charts that are shown to effectively guide the design of the ultra-thin deployable structure. The computational strategy discussed herein is general and can be applied to different problems in structural and materials design, with the potential of finding relevant designs within high-dimensional spaces.", "date": "2017-09", "date_type": "published", "publisher": "HafenCity University", "id_number": "CaltechAUTHORS:20191114-160021163", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191114-160021163", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Northrop Grumman Corporation" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Space-Solar-Power-Project" } ] }, "contributors": { "items": [ { "id": "B\u00f6gle-A", "name": { "family": "B\u00f6gle", "given": "Annette" } }, { "id": "Grohmann-M", "name": { "family": "Grohmann", "given": "Manfred" } } ] }, "primary_object": { "basename": "MABessa_IASS17_MachineLearning_article_final.pdf", "url": "https://authors.library.caltech.edu/records/2db4w-zg518/files/MABessa_IASS17_MachineLearning_article_final.pdf" }, "pub_year": "2017", "author_list": "Bessa, Miguel A. and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/ed2ww-4eh93", "eprint_id": 77663, "eprint_status": "archive", "datestamp": "2023-08-19 04:09:59", "lastmod": "2024-01-13 20:27:56", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hoff-Jonathan", "name": { "family": "Hoff", "given": "Jonathan" } }, { "id": "Ramezani-Alireza", "name": { "family": "Ramezani", "given": "Alireza" }, "orcid": "0000-0002-3391-5288" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Hutchinson-Seth", "name": { "family": "Hutchinson", "given": "Seth" }, "orcid": "0000-0002-3949-6061" } ] }, "title": "Reducing Versatile Bat Wing Conformations to a 1-DoF Machine", "ispublished": "unpub", "full_text_status": "public", "keywords": "Aerial robotics, bats, biologically-inspired robots, kinematics", "note": "\u00a9 2017 Springer International Publishing AG. \n\nFirst Online: 16 July 2017. \n\nWe would like to thank the team of graduate and undergraduate students from aerospace, electrical, computer, and mechanical engineering departments at the University of Illinois at Urbana-Champaign for their contribution to construct the initial prototype of B2. \n\nThe biological motion capture data set was provided by Dr. Kenneth Breuer and Dr. Sharon Swartz from Brown University. We would like to thank them in their assistance with this, as well as Jos\u00e9 Iriarte-D\u00edaz for compiling the data. \n\nThis work was supported by NSF Grant 1427111.\n\nAccepted Version - LM2017_010_final_v2_1_.pdf
", "abstract": "Recent works have shown success in mimicking the flapping flight of bats on the robotic platform Bat Bot (B2). This robot has only five actuators but retains the ability to flap and fold-unfold its wings in flight. However, this bat-like robot has been unable to perform folding-unfolding of its wings within the period of a wingbeat cycle, about 100 ms. The DC motors operating the spindle mechanisms cannot attain this folding speed. Biological bats rely on this periodic folding of their wings during the upstroke of the wingbeat cycle. It reduces the moment of inertia of the wings and limits the negative lift generated during the upstroke. Thus, we consider it important to achieve wing folding during the upstroke. A mechanism was designed to couple the flapping cycle to the folding cycle of the robot. We then use biological data to further optimize the mechanism such that the kinematic synergies of the robot best match those of a biological bat. This ensures that folding is performed at the correct point in the wingbeat cycle.", "date": "2017-07-16", "date_type": "published", "publisher": "Springer", "place_of_pub": "Cham, Switzerland", "pagerange": "181-192", "id_number": "CaltechAUTHORS:20170523-120929316", "isbn": "978-3-319-63536-1", "book_title": "Biomimetic and Biohybrid Systems", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170523-120929316", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "CMMI-1427111" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Mangan-M", "name": { "family": "Mangan", "given": "Michael" } }, { "id": "Cutkosky-M-R", "name": { "family": "Cutkosky", "given": "Mark" } }, { "id": "Mura-A", "name": { "family": "Mura", "given": "Anna" } }, { "id": "Verschure-P-F-M-J", "name": { "family": "Verschure", "given": "Paul F. M. J." } }, { "id": "Prescott-T", "name": { "family": "Prescott", "given": "Tony" } }, { "id": "Lepora-N", "name": { "family": "Lepora", "given": "Nathan" } } ] }, "doi": "10.1007/978-3-319-63537-8_16", "primary_object": { "basename": "LM2017_010_final_v2_1_.pdf", "url": "https://authors.library.caltech.edu/records/ed2ww-4eh93/files/LM2017_010_final_v2_1_.pdf" }, "pub_year": "2017", "author_list": "Hoff, Jonathan; Ramezani, Alireza; et el." }, { "id": "https://authors.library.caltech.edu/records/whzaf-n4734", "eprint_id": 77661, "eprint_status": "archive", "datestamp": "2023-08-19 04:09:53", "lastmod": "2024-01-13 20:27:54", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ramezani-Alireza", "name": { "family": "Ramezani", "given": "Alireza" }, "orcid": "0000-0002-3391-5288" }, { "id": "Syed-U-A", "name": { "family": "Ahmed", "given": "Syed Usman" } }, { "id": "Hoff-Jonathan", "name": { "family": "Hoff", "given": "Jonathan" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Hutchinson-Seth", "name": { "family": "Hutchinson", "given": "Seth" }, "orcid": "0000-0002-3949-6061" } ] }, "title": "Describing Robotic Bat Flight with Stable Periodic Orbits", "ispublished": "unpub", "full_text_status": "public", "keywords": "Bio-inspired robot, bat, Poincare, periodic orbit, control", "note": "\u00a9 Springer International Publishing AG 2017. \n\nFirst Online: 16 July 2017.\n\nAccepted Version - LM2017_011_final_v2.pdf
", "abstract": "From a dynamic system point of view, bat locomotion stands out among other forms of flight. During a large part of bat wingbeat cycle the moving body is not in a static equilibrium. This is in sharp contrast to what we observe in other simpler forms of flight such as insects, which stay at their static equilibrium. Encouraged by biological examinations that have revealed bats exhibit periodic and stable limit cycles, this work demonstrates that one effective approach to stabilize articulated flying robots with bat morphology is locating feasible limit cycles for these robots; then, designing controllers that retain the closed-loop system trajectories within a bounded neighborhood of the designed periodic orbits. This control design paradigm has been evaluated in practice on a recently developed bio-inspired robot called Bat Bot (B2).", "date": "2017-07-16", "date_type": "published", "publisher": "Springer", "place_of_pub": "Cham", "pagerange": "394-405", "id_number": "CaltechAUTHORS:20170523-114359601", "isbn": "978-3-319-63536-1", "book_title": "Biomimetic and Biohybrid Systems", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170523-114359601", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Mangan-M", "name": { "family": "Mangan", "given": "Michael" } }, { "id": "Cutosky-M", "name": { "family": "Cutosky", "given": "Mark" } }, { "id": "Mura-A", "name": { "family": "Mura", "given": "Anna" } }, { "id": "Verschure-P-F-M-J", "name": { "family": "Verschure", "given": "Paul F. M. J." } }, { "id": "Prescott-T", "name": { "family": "Prescott", "given": "Tony" } }, { "id": "Lepora-N", "name": { "family": "Lepora", "given": "Nathan" } } ] }, "doi": "10.1007/978-3-319-63537-8_33", "primary_object": { "basename": "LM2017_011_final_v2.pdf", "url": "https://authors.library.caltech.edu/records/whzaf-n4734/files/LM2017_011_final_v2.pdf" }, "pub_year": "2017", "author_list": "Ramezani, Alireza; Ahmed, Syed Usman; et el." }, { "id": "https://authors.library.caltech.edu/records/bjn4y-xt143", "eprint_id": 87558, "eprint_status": "archive", "datestamp": "2023-08-19 03:59:55", "lastmod": "2024-01-14 20:18:53", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Mello-M", "name": { "family": "Mello", "given": "Michael" }, "orcid": "0000-0003-2129-9235" }, { "id": "Kettenbeil-C", "name": { "family": "Kettenbeil", "given": "Christian" } }, { "id": "Bischann-Moriah", "name": { "family": "Bischann", "given": "Moriah" }, "orcid": "0000-0002-6674-5158" }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "Guruswami" }, "orcid": "0000-0002-2912-0001" } ] }, "title": "Heterodyne diffracted beam photonic Doppler velocimeter (DPDV) for measurement of transverse and normal particle velocities in pressure-shear plate impact experiments", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2018 AIP Publishing LLC. \n\nPublished Online: 03 July 2018. \n\nThe authors are grateful for support from the Office of Naval Research (Award No. N00014-16-1-2839) for the development of the PSPI capability at high pressures and the Air Force Office of Scientific Research (Award No. FA9550-12-1-0091) for the development of the heterodyne diffracted beam photonic Doppler velocimeter (DPDV) system.\n\nPublished - 1.5045016.pdf
", "abstract": "Pressure-shear plate impact (PSPI) experiments have traditionally relied on free space beam interferometers such as the transverse displacement interferometer (TDI) and normal displacement interferometer (NDI) or normal velocity interferometer (NVI), to measure transverse and normal velocities at the rear surface of the target plate [1]. Alternative interferometer schemes feature a dual beam VISAR arrangement [2] and a recently developed all fiber-optic TDI-NDI/PDV configuration [3]. Here, we present a heterodyne diffracted beam PDV (DPDV) which interferes a pair of symmetrically diffracted 1st order beams produced by a thin, specular, metallic grating deposited on the rear surface of the target plate. Each beam is collected by a fiber-optic probe and directed to interfere with a reference beam of a slightly increased wavelength to create an upshifted carrier signal frequency at zero particle velocity. Signal frequencies are extracted from the two fringe records using a moving-window DFT algorithm and then linearly combined in a post processing step to decouple the normal and transverse velocities. The 0th order beam can also be interfered in a heterodyne PDV to obtain an additional independent measurement of the normal particle velocity [4]. An overview of the DPDV configuration is presented along with a derivation of the interferometer sensitivities to transverse and normal particle velocities. Results from a normal impact experiment conducted on y-cut \u03b1-quartz are presented as experimental validation.", "date": "2017-07", "date_type": "published", "publisher": "American Institute of Physics", "place_of_pub": "Melville, NY", "pagerange": "Art. No. 160017", "id_number": "CaltechAUTHORS:20180705-135444147", "isbn": "978-0-7354-1693-2", "book_title": "Shock Compression of Condensed Matter - 2017", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180705-135444147", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-16-1-2839" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-12-1-0091" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Chau-Ricky", "name": { "family": "Chau", "given": "Ricky" } }, { "id": "Germann-Timothy-C", "name": { "family": "Germann", "given": "Timothy C." } }, { "id": "Lane-Matthew-D", "name": { "family": "Lane", "given": "Matthew D." } }, { "id": "Brown-Eric-N", "name": { "family": "Brown", "given": "Eric N." } }, { "id": "Eggert-Jon-H", "name": { "family": "Eggert", "given": "Jon H." } }, { "id": "Knudson-Marcus-D", "name": { "family": "Knudson", "given": "Marcus D." } } ] }, "doi": "10.1063/1.5045016", "primary_object": { "basename": "1.5045016.pdf", "url": "https://authors.library.caltech.edu/records/bjn4y-xt143/files/1.5045016.pdf" }, "pub_year": "2017", "author_list": "Mello, Michael; Kettenbeil, Christian; et el." }, { "id": "https://authors.library.caltech.edu/records/pfg99-kwv23", "eprint_id": 87557, "eprint_status": "archive", "datestamp": "2023-08-19 03:59:50", "lastmod": "2024-01-14 20:18:51", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Jiao-Tong", "name": { "family": "Jiao", "given": "T." } }, { "id": "Kettenbeil-C", "name": { "family": "Kettenbeil", "given": "C." } }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "G." }, "orcid": "0000-0002-2912-0001" }, { "id": "Clifton-R-J", "name": { "family": "Clifton", "given": "R. J." } } ] }, "title": "Experimental investigation of the shearing resistance of SODA-Lime glass at pressures of 9\u2005GPa and strain rates of 10^6 s^(-1)", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2018 AIP Publishing LLC. \n\nPublished Online: 03 July 2018.\n\nThis research is supported by the Office of Naval Research: N00014-16-1-2839; Naval Materials Division; Dr. Roshdy Barsoum, Program Officer.\n\nPublished - 1.5044826.pdf
", "abstract": "Pressure-Shear Plate Impact (PSPI) experiments were conducted to measure the high-rate shearing resistance of soda-lime glass at pressures of 9\u2005GPa and at shearing rates of approximately 10^6 s^(\u22121). Samples of soda lime glass, 5\u2005\u00b5m thick, were sandwiched between pure tungsten carbide (WC) plates and impacted by pure WC flyers. Impacting plates were inclined to the direction of approach by an angle of 18\u00b0. Normal stress and shearing resistance of the sample were calculated from measured free surface velocities using 1D elastic wave theory. The experimental results show that, at a pressure of 9GPa, the shear stress increases almost linearly up to 1\u2005GPa and then falls quickly to approximately 0.3\u2005GPa \u2014 after which it decreases slowly to approximately 0.17\u2005GPa. Comparisons with results of previous experiments on nominally identical samples, impacted to generate lower peak pressures, showed the peak shearing resistance to be much higher at higher pressures; however, the sharp fall in shearing resistance occurs at comparable shear strains (1.5-2).", "date": "2017-07", "date_type": "published", "publisher": "American Institute of Physics", "place_of_pub": "Melville, NY", "pagerange": "Art. No. 070017", "id_number": "CaltechAUTHORS:20180705-134213412", "isbn": "978-0-7354-1693-2", "book_title": "Shock Compression of Condensed Matter - 2017", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180705-134213412", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-16-1-2839" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Chau-Ricky", "name": { "family": "Chau", "given": "Ricky" } }, { "id": "Germann-T-C", "name": { "family": "Germann", "given": "Timothy C." } }, { "id": "Lane-M-D", "name": { "family": "Lane", "given": "Matthew D." } }, { "id": "Brown-E-N", "name": { "family": "Brown", "given": "Eric N." } }, { "id": "Eggert-J-H", "name": { "family": "Eggert", "given": "Jon H." } }, { "id": "Knudson-M-D", "name": { "family": "Knudson", "given": "Marcus D." } } ] }, "doi": "10.1063/1.5044826", "primary_object": { "basename": "1.5044826.pdf", "url": "https://authors.library.caltech.edu/records/pfg99-kwv23/files/1.5044826.pdf" }, "pub_year": "2017", "author_list": "Jiao, T.; Kettenbeil, C.; et el." }, { "id": "https://authors.library.caltech.edu/records/nrj4p-kx470", "eprint_id": 87556, "eprint_status": "archive", "datestamp": "2023-08-19 03:59:45", "lastmod": "2024-01-14 20:18:49", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kettenbeil-Christian", "name": { "family": "Kettenbeil", "given": "Christian" } }, { "id": "Mello-M", "name": { "family": "Mello", "given": "Michael" }, "orcid": "0000-0003-2129-9235" }, { "id": "Jiao-Tong", "name": { "family": "Jiao", "given": "Tong" } }, { "id": "Clifton-Rodney-J", "name": { "family": "Clifton", "given": "Rodney J." } }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "Guruswami" }, "orcid": "0000-0002-2912-0001" } ] }, "title": "Pressure-shear plate impact experiment on soda-lime glass at a pressure of 30 GPa and strain rate of 4\u00b710^7 s^(-1)", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2018 AIP Publishing LLC. \n\nPublished Online: 03 July 2018.\n \n\nThe authors are grateful for support from the Office of Naval Research (Award No. N00014-16-1-2839) for the development of the PSPI capability at high pressures and the Air Force Office of Scientific Research (Award No. FA9550-12-1-0091) for development of the PDV-DPDV interferometer system.\n\nPublished - 1.5044828.pdf
", "abstract": "Recent modifications of a powder gun facility at Caltech have enabled pressure-shear plate impact (PSPI) experiments in a regime of pressures and strain rates that were previously unaccessible. A novel heterodyne diffracted beam photonic Doppler velocimeter (DPDV) has also been developed for simultaneous measurement of the normal and transverse particle velocity histories using the \u00b11st order diffracted beams produced by a 400 lines/mm diffraction grating deposited onto the polished rear surface of the impacted target plate. We present and interpret the results of a PSPI experiment conducted on a 5 \u00b5m thick soda-lime glass sample subjected to a normal stress of 30 GPa and a shear strain rate of 4 \u00b7 10^7 s^(\u20131). Transverse particle velocity measurements reveal a peak shear stress level of 1.25 GPa up to a shear strain value of 2.2, followed by a precipitous drop in stress and complete loss of shear strength.", "date": "2017-07", "date_type": "published", "publisher": "American Institute of Physics", "place_of_pub": "Melville, NY", "pagerange": "Art. No. 070019", "id_number": "CaltechAUTHORS:20180705-132900622", "isbn": "978-0-7354-1693-2", "book_title": "Shock Compression of Condensed Matter - 2017", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180705-132900622", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-16-1-2839" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-12-1-0091" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Chau-Ricky", "name": { "family": "Chau", "given": "Ricky" } }, { "id": "Germann-Timothy-C", "name": { "family": "Germann", "given": "Timothy C." } }, { "id": "Lane-Matthew-D", "name": { "family": "Lane", "given": "Matthew D." } }, { "id": "Brown-Eric-N", "name": { "family": "Brown", "given": "Eric N." } }, { "id": "Eggert-Jon-H", "name": { "family": "Eggert", "given": "Jon H." } }, { "id": "Knudson-Marcus-D", "name": { "family": "Knudson", "given": "Marcus D." } } ] }, "doi": "10.1063/1.5044828", "primary_object": { "basename": "1.5044828.pdf", "url": "https://authors.library.caltech.edu/records/nrj4p-kx470/files/1.5044828.pdf" }, "pub_year": "2017", "author_list": "Kettenbeil, Christian; Mello, Michael; et el." }, { "id": "https://authors.library.caltech.edu/records/eyfkf-27n96", "eprint_id": 84744, "eprint_status": "archive", "datestamp": "2023-08-19 03:58:54", "lastmod": "2023-10-18 16:39:38", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Veilleux-J-C", "name": { "family": "Veilleux", "given": "Jean-Christophe" }, "orcid": "0000-0002-5420-9411" }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "Joseph E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "Impulsively-Generated Pressure Transients and Strains in a Cylindrical Fluid-Filled Tube Terminated by a Converging Section", "ispublished": "unpub", "full_text_status": "public", "keywords": "Pressure, Fluids, Transients (Dynamics)", "note": "\u00a9 2017 ASME.", "abstract": "The syringe in a subcutaneous autoinjector may be subjected to internal pressure transients due to the normal operation of the injection mechanism. These transients are similar to transients in fluid-filled pipelines observed during water hammer events. In this paper, the effect of an air gap in the syringe and a converging section are studied experimentally and numerically in a model system which consists of a fluid-filled metal tube that is impulsively loaded with a projectile to simulate the action of the autoinjector mechanism operation. \n\nThe air between the buffer and the water results in a complex interaction between the projectile and the buffer. Also, there are tension waves inside the tube due to the presence of a free surface, and this causes distributed cavitation which, in turn, gives rise to steepening of the pressure waves. The converging section can amplify the pressure waves if the wave front is sharp. Pressures as high as 50 MPa have been measured at the apex of the cone with impact velocities of 5.5 m/s.", "date": "2017-07", "date_type": "published", "publisher": "American Society of Mechanical Engineers", "place_of_pub": "New York, NY", "pagerange": "Art. No. V004T04A005", "id_number": "CaltechAUTHORS:20180208-150514369", "isbn": "978-0-7918-5797-7", "book_title": "ASME 2017 Pressure Vessels and Piping Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180208-150514369", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1115/PVP2017-65471", "pub_year": "2017", "author_list": "Veilleux, Jean-Christophe and Shepherd, Joseph E." }, { "id": "https://authors.library.caltech.edu/records/kt4zj-a7s05", "eprint_id": 78721, "eprint_status": "archive", "datestamp": "2023-08-19 03:22:32", "lastmod": "2023-10-26 00:19:42", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bandyopadhyay-S", "name": { "family": "Bandyopadhyay", "given": "Saptarshi" } }, { "id": "Baldini-F", "name": { "family": "Baldini", "given": "Francesca" } }, { "id": "Foust-Rebecca", "name": { "family": "Foust", "given": "Rebecca" }, "orcid": "0000-0003-1470-1716" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Rahmani-A", "name": { "family": "Rahmani", "given": "Amir" } }, { "id": "de-la-Croix-J-P", "name": { "family": "de la Croix", "given": "Jean-Pierre" } }, { "id": "Hadaegh-F-Y", "name": { "family": "Hadaegh", "given": "Fred Y." } } ] }, "title": "Distributed Fast Motion Planning for Spacecraft Swarms in Cluttered Environments Using Spherical Expansions and Sequence of Convex Optimization Problems", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a92017 California Institute of Technology. Government sponsorship acknowledged. \n\nThis work was supported by the Jet Propulsion Laboratory's Research and Technology Development (R&TD) program. Part of the research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.\n\nPublished - IWSCFF_FMP_multiagent_v4.pdf
", "abstract": "This paper presents a novel guidance algorithm for spacecraft swarms in an environment cluttered with many obstacles like a debris field or the asteroid belt. The objective of this algorithm is to reconfigure the swarm to a desired formation in a distributed manner while minimizing fuel and avoiding collisions among themselves and with the obstacles. The agents first use a spherical-expansion-based sampling algorithm to cooperatively explore the workspace and find paths to the desired terminal positions. Using a distributed assignment algorithm, the agents converge on an optimal assignment of the target locations in the desired formation. Then each agent generates a locally optimal trajectory from its current location to its terminal position by solving a sequence of convex optimization problems. As the agent moves along this trajectory, it receives the position of other agents and\nupdates its trajectory to avoid collisions with other agents and the obstacles. Thus the swarm achieves the desired formation in a distributed manner while avoiding collisions. Moreover, this algorithm is computationally efficient, therefore it can be implemented onboard resource-constrained spacecraft. Simulations results show that the proposed distributed algorithm can be used by a spacecraft swarm to reconfigure a desired formation around an asteroid in a collision-free manner.", "date": "2017-06", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20170630-095327924", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170630-095327924", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" }, { "agency": "JPL Research and Technology Development Fund" } ] }, "other_numbering_system": { "items": [ { "id": "17-42", "name": "IWSCFF" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "primary_object": { "basename": "IWSCFF_FMP_multiagent_v4.pdf", "url": "https://authors.library.caltech.edu/records/kt4zj-a7s05/files/IWSCFF_FMP_multiagent_v4.pdf" }, "pub_year": "2017", "author_list": "Bandyopadhyay, Saptarshi; Baldini, Francesca; et el." }, { "id": "https://authors.library.caltech.edu/records/gx87d-30m64", "eprint_id": 78723, "eprint_status": "archive", "datestamp": "2023-08-19 03:22:36", "lastmod": "2023-10-26 00:19:48", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Foust-Rebecca", "name": { "family": "Foust", "given": "Rebecca C." }, "orcid": "0000-0003-1470-1716" }, { "id": "Nakka-Yashwanth-K", "name": { "family": "Nakka", "given": "Yashwanth K." }, "orcid": "0000-0001-7897-3644" }, { "id": "Saxena-Ayush", "name": { "family": "Saxena", "given": "Ayush" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Hadaegh-F-Y", "name": { "family": "Hadaegh", "given": "Fred Y." } } ] }, "title": "Automated Rendezvous and Docking Using Tethered Formation Flight", "ispublished": "unpub", "full_text_status": "public", "note": "This work was supported by a NASA Space Technology Research Fellowship. Government sponsorship is acknowledged. This research was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the NASA.\n\nPublished - IWSCFF_paper_Tethered_Dynamics.pdf
", "abstract": "This paper analyzes capture strategies for tether-based autonomous rendezvous and docking. Once both spacecrafts are connected by tethers, docking is achieved through the use of reaction wheels and tether motors without the use of propellant. Autonomous rendezvous and docking is crucial for many upcoming missions including on-orbit servicing and potential Mars missions. The tether-based capture strategies investigated are a spin-up tether deployment and a free-flying child spacecraft attaching the tether. These strategies are compared to a traditional two-agent propulsive docking strategy. The capture strategies are simulated from initial orbit through to completed dock, with the total fuel consumption and dock time compared, along with initial pointing/location requirements. In addition to having lower fuel cost, the tether-based strategies are also more reliable due to redundancy, since tethers can be reeled back in and multiple tethers can be stored for use in case of primary tether failure.", "date": "2017-06", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20170630-100154807", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170630-100154807", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" }, { "agency": "NASA Space Technology Research Fellowship" } ] }, "other_numbering_system": { "items": [ { "id": "17-58", "name": "IWSCFF" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "primary_object": { "basename": "IWSCFF_paper_Tethered_Dynamics.pdf", "url": "https://authors.library.caltech.edu/records/gx87d-30m64/files/IWSCFF_paper_Tethered_Dynamics.pdf" }, "pub_year": "2017", "author_list": "Foust, Rebecca C.; Nakka, Yashwanth K.; et el." }, { "id": "https://authors.library.caltech.edu/records/geqnd-t1923", "eprint_id": 77662, "eprint_status": "archive", "datestamp": "2023-08-19 03:19:10", "lastmod": "2023-10-25 23:20:31", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Syed-U-A", "name": { "family": "Syed", "given": "Usman A." } }, { "id": "Ramezani-Alireza", "name": { "family": "Ramezani", "given": "Alireza" }, "orcid": "0000-0002-3391-5288" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Hutchinson-Seth", "name": { "family": "Hutchinson", "given": "Seth" }, "orcid": "0000-0002-3949-6061" } ] }, "title": "From Rousettus aegyptiacus (bat) Landing to Robotic Landing: Regulation of CG-CP Distance Using a Nonlinear Closed-Loop Feedback", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2017 IEEE.\n\nAccepted Version - ICRA17_2003_FI.pdf
", "abstract": "Bats are unique in that they can achieve unrivaled agile maneuvers due to their functionally versatile wing conformations. Among these maneuvers, roosting (landing) has captured attentions because bats perform this acrobatic maneuver with a great composure. This work attempts to reconstruct bat landing maneuvers with a Micro Aerial Vehicle (MAV) called Allice. Allice is capable of adjusting the position of its Center of Gravity (CG) with respect to the Center of Pressure (CP) using a nonlinear closed-loop feedback. This nonlinear control law, which is based on the method of input-output feedback linearization, enables attitude regulations through variations in CG-CP distance. To design the model-based nonlinear controller, the Newton-Euler dynamic model of the robot is considered, in which the aerodynamic coefficients of lift and drag are obtained experimentally. The performance of the proposed control architecture is validated by conducting several experiments.", "date": "2017-06", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "3560-3567", "id_number": "CaltechAUTHORS:20170523-114956940", "isbn": "978-1-5090-4633-1", "book_title": "2017 IEEE International Conference on Robotics and Automation", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170523-114956940", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "collection": "CaltechAUTHORS", "local_group": { "items": [ { "id": "GALCIT", "value": "GALCIT" } ] }, "doi": "10.1109/ICRA.2017.7989408", "primary_object": { "basename": "ICRA17_2003_FI.pdf", "url": "https://authors.library.caltech.edu/records/geqnd-t1923/files/ICRA17_2003_FI.pdf" }, "pub_year": "2017", "author_list": "Syed, Usman A.; Ramezani, Alireza; et el." }, { "id": "https://authors.library.caltech.edu/records/2jq6j-xh523", "eprint_id": 78719, "eprint_status": "archive", "datestamp": "2023-08-19 03:22:27", "lastmod": "2023-10-26 00:19:36", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Goel-Ashish", "name": { "family": "Goel", "given": "Ashish" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Trajectory Design of a Spacecraft Formation for Space-Based Solar Power Using Sequential Convex Programming", "ispublished": "unpub", "full_text_status": "public", "note": "The authors thank Northrop Grumman Corporation for supporting this project. We also thank all other members of the SSPI team at Caltech for their valuable inputs.\n\nPublished - IWSCFF_SPI.pdf
", "abstract": "The concept of collecting solar power in space and transmitting it to the Earth using microwaves has been studied by numerous researchers in the past. The Space Solar Power Initiative (SSPI) at Caltech is a collaborative project to bring about the scientific and technological innovations necessary for enabling a space-based solar power system. The proposed system comprises an array of ultra-light, membrane-like deployable modules with high efficiency photovoltaic (PV) concentrators and microwave transmission antennas embedded in the structure. Each module is 60m x 60m in size and in the final configuration, hundreds of these modules span a 3km x 3km array in a geosynchronous orbit. As this formation goes around the Earth, the orientation and position of each module has to be changed so as to optimize the angle made by the photovoltaic surface with respect to the sun and by the antenna surface with respect to the receiving station on Earth. In order to achieve high antenna array efficiency, the modules have to remain in a tight formation with an edge-to-edge distance on the order of a few meters. In addition, the modules also have to avoid collisions and maintain a planar configuration to avoid the possibility of both PV and RF shadowing. In this paper, we present the trajectory design that achieves the dual goal of minimizing the propellant usage and maximizing the power delivered to the ground station, while meeting the various orbital constraints. The optimal control problem is solved using sequential convex programming for a 4 x 4 formation and the results obtained show that it is possible to maintain the formation for 11 years in a geo-synchronous orbit with relatively small amounts of propellant. This serves as a critical achievement in the path towards realizing the objective of space-based solar power.", "date": "2017-06", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20170630-094657577", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170630-094657577", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Northrop Grumman Corporation" } ] }, "other_numbering_system": { "items": [ { "id": "17-43", "name": "IWSCFF" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Space-Solar-Power-Project" } ] }, "primary_object": { "basename": "IWSCFF_SPI.pdf", "url": "https://authors.library.caltech.edu/records/2jq6j-xh523/files/IWSCFF_SPI.pdf" }, "pub_year": "2017", "author_list": "Goel, Ashish; Chung, Soon-Jo; et el." }, { "id": "https://authors.library.caltech.edu/records/btfta-3yv34", "eprint_id": 78952, "eprint_status": "archive", "datestamp": "2023-08-21 20:51:25", "lastmod": "2024-01-13 20:32:23", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Dasari-S", "name": { "family": "Dasari", "given": "Sudeep" }, "orcid": "0000-0003-2600-2779" }, { "id": "Dorn-C", "name": { "family": "Dorn", "given": "Charles" }, "orcid": "0000-0001-6516-2586" }, { "id": "Yang-Yongchao", "name": { "family": "Yang", "given": "Yongchao" }, "orcid": "0000-0003-1776-3306" }, { "id": "Farrar-C", "name": { "family": "Farrar", "given": "Charles" } }, { "id": "Larson-A", "name": { "family": "Larson", "given": "Amy" } }, { "id": "Mascare\u00f1as-D", "name": { "family": "Mascare\u00f1as", "given": "David" } } ] }, "title": "Extraction of Full-Field Structural Dynamics from Digital Video Measurements in Presence of Large Rigid Body Motion", "ispublished": "unpub", "full_text_status": "public", "keywords": "Operational modal analysis; Video processing; Blind source separation; Motion magnification; Rigid motion", "note": "\u00a9 2017 The Society for Experimental Mechanics, Inc. \n\nFirst Online: 18 April 2017.", "abstract": "Video cameras offer a versatile high resolution alternative to traditional sensor apparatuses for full field structural dynamics analysis. Previous work has extended phase based motion magnification techniques to achieve state of the art results in vibrational and structural analysis. One limitation on the current approach is that it does not work very well in situations where substantial rigid body motion is present in the scene. The large rigid motion drowns out the tiny vibrations that are relevant for a full-field structural analysis. This work extends upon previous phase based motion algorithms in order to allow them to work even in cases with large rigid body motion present. Through a keypoint tracking and video cropping scheme rigid body motion is subtracted from video streams, while preserving the smaller motions of interest. After this preprocessing step, the new video stream can be passed into the full-field analysis scheme as usual, in order to get a full-field modal decomposition.", "date": "2017-04-18", "date_type": "published", "publisher": "Springer", "place_of_pub": "Cham, Switzerland", "pagerange": "91-95", "id_number": "CaltechAUTHORS:20170711-131834042", "isbn": "978-3-319-54734-3", "book_title": "Shock & Vibration, Aircraft/Aerospace, Energy Harvesting, Acoustics & Optics", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170711-131834042", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1007/978-3-319-54735-0_10", "pub_year": "2017", "author_list": "Dasari, Sudeep; Dorn, Charles; et el." }, { "id": "https://authors.library.caltech.edu/records/mvhzq-w3k04", "eprint_id": 103912, "eprint_status": "archive", "datestamp": "2023-08-19 02:29:46", "lastmod": "2023-10-20 16:50:51", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Melguizo-Gavilanes-J", "name": { "family": "Melguizo-Gavilanes", "given": "J." }, "orcid": "0000-0001-5174-6003" }, { "id": "Houim-R", "name": { "family": "Houim", "given": "R." } } ] }, "title": "Experimental and numerical study of flame acceleration and transition to detonation in narrow channels", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2017 The Combustion Institute.\n\nPublished - Melguizo-Gavilanes_2017p1270.pdf
", "abstract": "From a scientific point of view, Deflagration to Detonation Transition (DDT) continues to draw significant interest in the research community as an outstanding, physics-rich fundamental problem in combustion science. From a practical perspective, it is important to study and understand DDT in order to develop engineering correlations and simulation tools that can be applied to the prevention and mitigation of explosions. In the current study, flame acceleration and transition to detonation of stoichiometric H\u2082/O\u2082 mixts. in narrow channels was investigated using a combined exptl. and numerical approach. The exptl. setup included direct-, schlieren- and shadowgraph visualization of a 6 mm x 6 mm square channel of 1 m in length. The channel was closed in the region where the mixt. was ignited, and open at the other end. Exptl. x-t diagrams using shadowgraph, revealed that transition to detonation regularly occurred around the first two-thirds of the channel (~ 25 - 55 cm); close-ups to the ignition location using schlieren and shadowgraph visualization showed important details of the ignition kernel. Three-dimensional numerical simulations using quarter symmetry with a simplified chem.-diffusive model are in reasonable agreement with the exptl. results, and shed light into the DDT mechanism in this type of configuration.", "date": "2017-04", "date_type": "published", "publisher": "Combustion Institute", "place_of_pub": "Pittsburgh, PA", "pagerange": "1270-1275", "id_number": "CaltechAUTHORS:20200615-093539656", "isbn": "978-1-5108-4238-0", "book_title": "10th U.S. Combustion Meeting", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200615-093539656", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "primary_object": { "basename": "Melguizo-Gavilanes_2017p1270.pdf", "url": "https://authors.library.caltech.edu/records/mvhzq-w3k04/files/Melguizo-Gavilanes_2017p1270.pdf" }, "pub_year": "2017", "author_list": "Melguizo-Gavilanes, J. and Houim, R." }, { "id": "https://authors.library.caltech.edu/records/1xpk0-gk006", "eprint_id": 78223, "eprint_status": "archive", "datestamp": "2023-08-19 01:50:34", "lastmod": "2023-10-25 23:53:39", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Gat-I", "name": { "family": "Gat", "given": "Ilana" }, "orcid": "0000-0003-0223-0507" }, { "id": "Talon-T", "name": { "family": "Talon", "given": "Thibaud" } } ] }, "title": "Lunarport: A proposed Lunar-resource station to expand deep-space travel horizons", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2017 IEEE. \n\nThe authors thank Caltech, GALCIT, JPL, and KISS for the continued support of this event. In particular, Michele Judd, Dimity Nelson, Jamie Meighen-Sei, and John Kastanas have been instrumental in the success of all the Caltech Space Challenges. The authors would also like to acknowledge support from and thank the Space Challenge Caltech advisor Paul Dimotakis funded by the Caltech Northrop Chair, and the JPL advisors Jakob Van Zyl and Anthony Freeman. Past Caltech Space Challenge chairs and technical leads Prakhar Mehrotra, Jonathan Mihaly, Nick Parziale, Jason Rabinovich, Niccolo Cymbalist, Hayden Burgoyne, and Jay Qi are thanked for their tremendous help and support on the 2017 challenge, and for their hard work on past challenges. Erika Figueroa Schibber, Francesca Baldini, Haolu Zhang, Maria Sakovsky, and Yuchen Wei are thanked for their help on the 2017 Caltech Space Challenge. \n\nFinancial support for this event is provided by Airbus Defence and Space, the Keck Institute for Space Studies (KISS), Northrop Grumman, Boeing, Schlumberger, JPL, GALCIT, Caltech, and Microsoft. A full list of current and past sponsors can be found at acechallenge.caltech.edu/sponsors. The authors would like to acknowledge a personal support by the National Science Foundation Graduate Research Fellowship Program under Grant No. DGE-1144469.", "abstract": "Deep-space travel is limited by the costly voyage to leave Earth's atmosphere and gravitational pull. The volume of propellants per unit mass of the payload required for that segment constrains the payload size and payload destination. To circumvent that limitation, this paper presents the feasibility of a refueling station using Lunar resources, called Lunarport. On Earth's moon, an unmanned station will robotically mine, produce, and store fuel and oxidizer from water ice at the poles. A first-stage-like rocket, called the Lunar Resupply Shuttle (LRS), stationed there and propelled with mined resources, will launch and dock with a passing payload-carrying rocket. That rocket will be reloaded with propellants by the LRS, after which the LRS will detach and the payload-carrying rocket will continue its journey to its desired trajectory. The LRS will wait in Lower Lunar Orbit (LLO, to avoid deterioration from Lunar regolith) until another payload-carrying rocket is launched from Earth, after which, the LRS will land back on the Moon, reload propellants, and launch again to dock with the next rocket. This paper elaborates on Lunarport, presenting proof-of-concept calculations of the increase in payload size sent to various payload destinations as well as a cost-benefit analysis. By way of example, NASA's Space Launch System (SLS) en-route to Mars that refuels at Lunarport can have a payload approximately 17 metric tons (mT) heavier than one traveling straight to Mars from Earth. This increase of more than 50% [1] is just to a relatively nearby planet \u2014 Mars. Sending a payload farther offers larger benefits with Lunarport. Wear-and-tear issues the port will be subjected to are also discussed. A full analysis of Lunarport will be done during the 2017 Caltech Space Challenge sponsored by Airbus Defence and Space held from March 26\u201331, 2017.", "date": "2017-03", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "1-8", "id_number": "CaltechAUTHORS:20170614-164521270", "isbn": "978-1-5090-1613-6", "book_title": "2017 IEEE Aerospace Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170614-164521270", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Airbus Defense and Space" }, { "agency": "Keck Institute for Space Studies (KISS)" }, { "agency": "Northrop Grumman Corporation" }, { "agency": "Boeing Corporation" }, { "agency": "Schlumberger" }, { "agency": "JPL" }, { "agency": "GALCIT" }, { "agency": "Caltech" }, { "agency": "Microsoft" }, { "agency": "NSF Graduate Research Fellowship", "grant_number": "DGE-1144469" } ] }, "local_group": { "items": [ { "id": "Keck-Institute-for-Space-Studies" }, { "id": "GALCIT" } ] }, "doi": "10.1109/AERO.2017.7943623", "pub_year": "2017", "author_list": "Gat, Ilana and Talon, Thibaud" }, { "id": "https://authors.library.caltech.edu/records/v0wpe-pk203", "eprint_id": 78224, "eprint_status": "archive", "datestamp": "2023-08-19 01:50:42", "lastmod": "2023-10-25 23:53:48", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Goel-Ashish", "name": { "family": "Goel", "given": "Ashish" } }, { "id": "Lee-Nicolas", "name": { "family": "Lee", "given": "Nicolas" }, "orcid": "0000-0001-5500-1324" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Trajectory design of formation flying constellation for space-based solar power", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2017 IEEE. \n\nThe authors thank Northrop Grumman Corporation for supporting this project. We also thank all other members of the SSPI team at Caltech for their valuable inputs. Inputs from Dr. Daniel Scharf were very useful in the design of the periodic relative orbits. Nicolas Lee was supported during this work by a postdoctoral fellowship from the W. M. Keck Institute for Space Studies.", "abstract": "The concept of collecting solar power in space and transmitting it to the Earth using a microwave beam has appealed to the imagination of numerous researchers in the past. The Space Solar Power Initiative at Caltech is working towards turning this idea into reality, by developing the critical technologies necessary to make this an economically feasible solution. The proposed system comprises an array of ultralight, membrane-like deployable modules with high efficiency photovoltaics and microwave transmission antennas embedded in the structure. Each module is 60 m \u03c7 60 m in size and in the final configuration, \u223c2500 of these modules form a 3 km \u03c7 3 km array in a geosynchronous orbit. As the constellation orbits the Earth, the orientation and position of each module has to be changed so as to optimize the angle made by the photovoltaic surface with respect to the sun and by the antenna surface with respect to the receiving station on Earth. We derive the optimum orientation profile for the modules and find that modules with dual-sided RF transmission can provide 1.5 times more orbit-averaged power than modules with single-sided RF transmission. To carry out the corresponding orbital maneuvers, an optimization framework using the Hill-Clohessy-Wiltshire (HCW) equations is developed to achieve the dual goal of maximizing the power delivered, while minimizing the propellant required to carry out the desired orbital maneuvers. Results are presented for a constellation with modules in fixed relative positions and also for a constellation where the modules execute circularized periodic relative motion in the HCW frame. We show that the use of these periodic relative orbits reduces the propellant consumption from \u223c150 kg to \u223c50 kg. This drastic reduction makes the propellant mass a significantly smaller fraction of the module's dry mass (370 kg), thereby solving a major technical hurdle in the realization of space-based solar power.", "date": "2017-03", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "1-11", "id_number": "CaltechAUTHORS:20170614-164611614", "isbn": "978-1-5090-1613-6", "book_title": "2017 IEEE Aerospace Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170614-164611614", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Northrop Grumman Corporation" }, { "agency": "Keck Institute for Space Studies (KISS)" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Keck-Institute-for-Space-Studies" }, { "id": "Space-Solar-Power-Project" } ] }, "doi": "10.1109/AERO.2017.7943711", "pub_year": "2017", "author_list": "Goel, Ashish; Lee, Nicolas; et el." }, { "id": "https://authors.library.caltech.edu/records/ggqk7-nj973", "eprint_id": 97973, "eprint_status": "archive", "datestamp": "2023-08-19 01:02:00", "lastmod": "2023-10-18 16:55:44", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Leclerc-C", "name": { "family": "Leclerc", "given": "Christophe" } }, { "id": "Wilson-L-L", "name": { "family": "Wilson", "given": "Lee" } }, { "id": "Bessa-M-A", "name": { "family": "Bessa", "given": "Miguel A." } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Characterization of Ultra-Thin Composite Triangular Rollable and Collapsible Booms", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2017 American Institute of Aeronautics and Astronautics. \n\nThe authors acknowledge financial support from the Northrop Grumman Corporation, the Keck Institute for Space Studies and the Natural Sciences and Engineering Research Council of Canada.\n\nAccepted Version - LECLERC_Characterization-Ultra-ThinSMALL.pdf
", "abstract": "The paper studies the behavior of Triangular Rollable and Collapsible (TRAC) booms made from ultra-thin carbon fiber, with a total flange thickness of 71 \u00b5m. Both bending and torsional behavior of the deployed booms are studied using numerical analysis and experimental testing. The coiling of the booms around hubs of large radius is also studied.", "date": "2017-01-09", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2017-0172", "id_number": "CaltechAUTHORS:20190816-144341170", "isbn": "9781624104558", "book_title": "AIAA SciTech Forum : 4th AIAA Spacecraft Structures Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190816-144341170", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Northrop Grumman Corporation" }, { "agency": "Keck Institute for Space Studies (KISS)" }, { "agency": "Natural Sciences and Engineering Research Council of Canada (NSERC)" } ] }, "collection": "CaltechAUTHORS", "other_numbering_system": { "items": [ { "id": "2017-0172", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT", "value": "GALCIT" }, { "id": "Keck-Institute-for-Space-Studies", "value": "Keck Institute for Space Studies" }, { "id": "Space-Solar-Power-Project", "value": "Space Solar Power Project" } ] }, "doi": "10.2514/6.2017-0172", "primary_object": { "basename": "LECLERC_Characterization-Ultra-ThinSMALL.pdf", "url": "https://authors.library.caltech.edu/records/ggqk7-nj973/files/LECLERC_Characterization-Ultra-ThinSMALL.pdf" }, "pub_year": "2017", "author_list": "Leclerc, Christophe; Wilson, Lee; et el." }, { "id": "https://authors.library.caltech.edu/records/81rdd-jhj56", "eprint_id": 98092, "eprint_status": "archive", "datestamp": "2023-08-19 01:00:25", "lastmod": "2023-10-18 17:02:11", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Wei-Yuchen", "name": { "family": "Wei", "given": "Yuchen" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Modular Foldable Surfaces: a Novel Approach based on Spatial Mechanisms and Thin Shells", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2017 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 5 Jan 2017.", "abstract": "This paper investigates a set of novel techniques that lead to modular, deployable surface arrays which could be either flat or curved in their deployed shape. The two components of the proposed concepts are thin shells with smooth folds and spatial mechanisms with rolling hinges. Kinematics of the mechanism and motion of the shell has been shown to be fully compatible with each other during folding and unfolding. This basic module is then articulated to create multiple modular tessellations, which form a series of foldable surfaces. We further demonstrate that curvature could be introduced to the initially flat shells using bonded piezoceramic actuators. The techniques and concepts proposed in this paper could be valuable for the design of future deployable space-based telescope and other reflective arrays which require high shape precision with low storage area and volume.", "date": "2017-01-05", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2017-1345", "id_number": "CaltechAUTHORS:20190821-155916295", "isbn": "978-1-62410-455-8", "book_title": "4th AIAA Spacecraft Structures Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190821-155916295", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "collection": "CaltechAUTHORS", "other_numbering_system": { "items": [ { "id": "2017-1345", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT", "value": "GALCIT" } ] }, "doi": "10.2514/6.2017-1345", "pub_year": "2017", "author_list": "Wei, Yuchen and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/mjp70-gt490", "eprint_id": 98049, "eprint_status": "archive", "datestamp": "2023-08-19 01:00:16", "lastmod": "2023-10-18 16:59:50", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Umali-J-A", "name": { "family": "Umali", "given": "James" } }, { "id": "Wilson-L-L", "name": { "family": "Wilson", "given": "Lee" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Vibration Response of Ultralight Coilable Spacecraft Structures", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2017 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 5 Jan 2017. \n\nFinancial support from Northrop Grumman Corporation is gratefully acknowledged.\n\nAccepted Version - Umali+SciTech_Paper.pdf
", "abstract": "Dynamic assessment of ultralight wrapped spacecraft structures subject to the launch vibration environment is difficult, and has been foregone in many space programs in favor of purely experimental test campaigns. We present a numerical methodology to better understand the wrapped state of a structure and the dynamic behavior during launch vibration, enabling higher confidence in its survivability and greater understanding of the dynamic behavior at different scales, which vibration test approaches alone cannot achieve.", "date": "2017-01-05", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2017-1115", "id_number": "CaltechAUTHORS:20190820-152401055", "isbn": "978-1-62410-455-8", "book_title": "4th AIAA Spacecraft Structures Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190820-152401055", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Northrop Grumman Corporation" } ] }, "collection": "CaltechAUTHORS", "other_numbering_system": { "items": [ { "id": "2017-1115", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT", "value": "GALCIT" }, { "id": "Space-Solar-Power-Project", "value": "Space Solar Power Project" } ] }, "doi": "10.2514/6.2017-1115", "primary_object": { "basename": "Umali+SciTech_Paper.pdf", "url": "https://authors.library.caltech.edu/records/mjp70-gt490/files/Umali+SciTech_Paper.pdf" }, "pub_year": "2017", "author_list": "Umali, James; Wilson, Lee; et el." }, { "id": "https://authors.library.caltech.edu/records/yy02s-zf342", "eprint_id": 98051, "eprint_status": "archive", "datestamp": "2023-08-19 01:00:21", "lastmod": "2023-10-18 16:59:55", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Talon-T", "name": { "family": "Talon", "given": "T." } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "S." }, "orcid": "0000-0001-9373-3278" } ] }, "title": "In-space Shape Measurement of Large Planar Structures", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2017 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 5 Jan 2017. \n\nThis research was supported by the Northrop Grumman Corporation.\n\nAccepted Version - TalonAIAA2017.pdf
", "abstract": "A measurement and integration scheme is proposed to estimate the shape of a large planar structure in space. Lightweight sun sensors distributed on the structure measure the local angles relative to the sun. A reconstruction technique is introduced to estimate the shape of the satellite through a decomposition on a function basis. The estimated shape is determined by the coefficients associated with the basis functions which are calculated from the measurements. A trade-study to analyze the influence of different reconstruction schemes and the position of the sensors is presented. An optimization scheme minimizes the RMS error between the estimated and true shape. An experiment was conducted to show the feasibility and performance of the proposed system at the lab scale. Finally, a simulation of the accuracy of the presented solution on a 60 m space solar power module is performed. The expected error is 0.7 mm RMS using sensors every 30 cm.", "date": "2017-01-05", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2017-1116", "id_number": "CaltechAUTHORS:20190820-154603282", "isbn": "978-1-62410-455-8", "book_title": "4th AIAA Spacecraft Structures Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190820-154603282", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Northrop Grumman Corporation" } ] }, "collection": "CaltechAUTHORS", "other_numbering_system": { "items": [ { "id": "2017-1116", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT", "value": "GALCIT" }, { "id": "Space-Solar-Power-Project", "value": "Space Solar Power Project" } ] }, "doi": "10.2514/6.2017-1116", "primary_object": { "basename": "TalonAIAA2017.pdf", "url": "https://authors.library.caltech.edu/records/yy02s-zf342/files/TalonAIAA2017.pdf" }, "pub_year": "2017", "author_list": "Talon, T. and Pellegrino, S." }, { "id": "https://authors.library.caltech.edu/records/fcgt7-64f47", "eprint_id": 83491, "eprint_status": "archive", "datestamp": "2023-08-19 00:21:38", "lastmod": "2023-10-17 23:10:08", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Rosenberg-Kevin-T", "name": { "family": "Rosenberg", "given": "K." } }, { "id": "Saxton-Fox-T", "name": { "family": "Saxton-Fox", "given": "T." }, "orcid": "0000-0003-1328-4148" }, { "id": "Lozano-Dur\u00e1n-Adri\u00e1n", "name": { "family": "Lozano-Dur\u00e1n", "given": "A." }, "orcid": "0000-0001-9306-0261" }, { "id": "Towne-A", "name": { "family": "Towne", "given": "A." }, "orcid": "0000-0002-7315-5375" }, { "name": { "family": "McKeon", "given": "B. J." } } ] }, "title": "Toward low order models of wall turbulence using resolvent analysis", "ispublished": "unpub", "full_text_status": "public", "note": "Discussions with other CTR Summer Program participants, especially Mihailo Jovanovic, Peter Schmid, Xiaohua Wu and Armin Zare, were extremely helpful to the development of this work. The authors acknowledge use of computational resources from the Certainty cluster awarded by the National Science Foundation to CTR.\n\nPublished - 075_Rosenberg.pdf
", "abstract": "Resolvent analysis for wall turbulence has the potential to provide a physical basis for both sub-grid scale and dynamic wall models for large-eddy simulations (LES), and an explicit representation of the interface between resolved and modeled scales. Toward the development of such a wall model, direct numerical simulation results are used to represent the Reynolds stresses, formulated as the nonlinear feedback (forcing) to the linear(ized) Navier-Stokes equations. It is found from direct calculation of the Reynolds stress gradients that the (solenoidal) nonlinear feedback is coherent and consistent with energetic activity that is localized in the wall-normal direction. Further, there exists a spatial organization of this forcing that is correlated with individual(large) scales. A brief outlook for LES modeling is given.", "date": "2016-12", "date_type": "published", "publisher": "Center for Turbulence Research", "id_number": "CaltechAUTHORS:20171128-094432410", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171128-094432410", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF" } ] }, "collection": "CaltechAUTHORS", "local_group": { "items": [ { "id": "GALCIT", "value": "GALCIT" } ] }, "primary_object": { "basename": "075_Rosenberg.pdf", "url": "https://authors.library.caltech.edu/records/fcgt7-64f47/files/075_Rosenberg.pdf" }, "pub_year": "2016", "author_list": "Rosenberg, K.; Saxton-Fox, T.; et el." }, { "id": "https://authors.library.caltech.edu/records/6km8j-c4p73", "eprint_id": 108431, "eprint_status": "archive", "datestamp": "2023-08-19 00:24:30", "lastmod": "2023-10-23 17:02:05", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Silvis-Maurits-H", "name": { "family": "Silvis", "given": "M. H." }, "orcid": "0000-0003-0648-9794" }, { "id": "Trias-F-Xavier", "name": { "family": "Trias", "given": "F. X." }, "orcid": "0000-0002-5966-0703" }, { "id": "Abkar-Mahdi", "name": { "family": "Abkar", "given": "M." }, "orcid": "0000-0002-6220-870X" }, { "id": "Bae-Hyunji-Jane", "name": { "family": "Bae", "given": "H. J." }, "orcid": "0000-0001-6789-6209" }, { "id": "Lozano-Dur\u00e1n-Adri\u00e1n", "name": { "family": "Lozano-Dur\u00e1n", "given": "A." }, "orcid": "0000-0001-9306-0261" }, { "id": "Verstappen-Roel", "name": { "family": "Verstappen", "given": "R. W. C. P." }, "orcid": "0000-0001-8565-6188" } ] }, "title": "Exploring nonlinear subgrid-scale models and new characteristic length scales for large-eddy simulation", "ispublished": "unpub", "full_text_status": "public", "note": "We are grateful to Stefan Hickel for his assistance in setting up numerical simulations of\nrotating homogeneous isotropic turbulence. The authors also acknowledge use of computational resources from the Certainty cluster awarded by the National Science Foundation\nto CTR.\n\nPublished - 071_Silvis.pdf
", "abstract": "We study subgrid-scale modeling for large-eddy simulation of anisotropic turbulent flows on anisotropic grids.\nIn particular, we show how the addition of a velocity-gradient-based nonlinear model term to an eddy viscosity model provides a better representation of energy transfer.\nThis is shown to lead to improved predictions of rotating and nonrotating homogeneous isotropic turbulence.\n%We furthermore show that spanwise-rotating turbulent plane-channel flows form a challenging test case for large-eddy simulation.\nOur research further focuses on calculation of the subgrid characteristic length, a key element for any eddy viscosity model.\nIn the current work, we propose a new formulation of this quantity based on a Taylor series expansion of the subgrid stress tensor in the computational space.\nNumerical tests of decaying homogeneous isotropic turbulence and a plane-channel flow illustrate the robustness of this flow-dependent characteristic length scale with respect to mesh anisotropy.", "date": "2016-12", "date_type": "published", "publisher": "Stanford University", "id_number": "CaltechAUTHORS:20210315-110422387", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210315-110422387", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF" } ] }, "collection": "CaltechAUTHORS", "local_group": { "items": [ { "id": "GALCIT", "value": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Moin-Parviz", "name": { "family": "Moin", "given": "Parviz" } }, { "id": "Urzay-Javier", "name": { "family": "Urzay", "given": "Javier" } } ] }, "primary_object": { "basename": "071_Silvis.pdf", "url": "https://authors.library.caltech.edu/records/6km8j-c4p73/files/071_Silvis.pdf" }, "pub_year": "2016", "author_list": "Silvis, M. H.; Trias, F. X.; et el." }, { "id": "https://authors.library.caltech.edu/records/4eqmm-ry888", "eprint_id": 73280, "eprint_status": "archive", "datestamp": "2023-08-19 00:04:15", "lastmod": "2024-01-13 20:22:32", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Tumuklu-O", "name": { "family": "Tumuklu", "given": "Ozgur" } }, { "id": "Levin-D-A", "name": { "family": "Levin", "given": "Deborah A." } }, { "id": "Gimelshein-S-F", "name": { "family": "Gimelshein", "given": "Sergey F." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "Joanna M." }, "orcid": "0000-0003-3129-5035" } ] }, "title": "Modeling of near-continuum laminar boundary layer shocks using DSMC", "ispublished": "unpub", "full_text_status": "public", "keywords": "Shock-wave boundary layer interactions, hypersonic separated flows, DSMC", "note": "\u00a9 2016 AIP Publishing LLC. \n\nThe research is being performed at the University of Illinois Urbana-Champaign is supported by the Air Force Office of Scientific Research through AFOSR Grant No. FA9550-11-1-0129 with a subcontract award number 2010-06171-01 to UIUC. This research is also a part of the Blue Waters sustained-petascale computing project, which is supported by the National Science Foundation (awards OCI-0725070 and ACI-1238993) and the state of Illinois. Blue Waters is a joint effort of the University of Illinois at Urbana-Champaign and its National Center for Supercomputing Applications.\n\nPublished - 1.4967554.pdf
", "abstract": "The hypersonic flow of nitrogen gas over a double wedge was simulated by the DSMC method using two-dimensional and three-dimensional geometries. The numerical results were compared with experiments conducted in the HET facility for a high-enthalpy pure nitrogen flow corresponding to a free stream Mach number of approximately seven. Since the conditions for the double wedge case are near-continuum and surface heat flux and size of the separation are sensitive to DSMC numerical parameters, special attention was paid to the convergence of these parameters for both geometries. At the beginning of the simulation, the separation zone was predicted to be small and the heat flux values for the 2-D model were comparable to the experimental data. However, for increasing time, it was observed that the heat flux values and shock profile strongly deviated from the experiment. Investigation of a three-dimensional model showed that the flow is truly three-dimensional and the side edge pressure relief provides good agreement between simulations and the experiment.", "date": "2016-11-15", "date_type": "published", "publisher": "American Institute of Physics", "place_of_pub": "Melville, NY", "pagerange": "Art. No. 050004", "id_number": "CaltechAUTHORS:20170105-143010420", "isbn": "978-0-7354-1448-8", "book_title": "30th International Symposium on Rarefied Gas Dynamics", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170105-143010420", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-11-1-0129" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "2010-06171-01" }, { "agency": "NSF", "grant_number": "OCI-0725070" }, { "agency": "NSF", "grant_number": "ACI-1238993" }, { "agency": "State of Illinois" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Ketsdever-A", "name": { "family": "Ketsdever", "given": "Andrew" } }, { "id": "Struchtrup-H", "name": { "family": "Struchtrup", "given": "Henning" } } ] }, "doi": "10.1063/1.4967554", "primary_object": { "basename": "1.4967554.pdf", "url": "https://authors.library.caltech.edu/records/4eqmm-ry888/files/1.4967554.pdf" }, "pub_year": "2016", "author_list": "Tumuklu, Ozgur; Levin, Deborah A.; et el." }, { "id": "https://authors.library.caltech.edu/records/asfas-wqv51", "eprint_id": 73279, "eprint_status": "archive", "datestamp": "2023-08-19 00:04:10", "lastmod": "2024-01-13 20:22:30", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Tumuklu-O", "name": { "family": "Tumuklu", "given": "Ozgur" } }, { "id": "Levin-D-A", "name": { "family": "Levin", "given": "Deborah A." } }, { "id": "Gimelshein-S-F", "name": { "family": "Gimelshein", "given": "Sergey F." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "Joanna M." }, "orcid": "0000-0003-3129-5035" } ] }, "title": "Factors influencing flow steadiness in laminar boundary layer shock interactions", "ispublished": "unpub", "full_text_status": "public", "keywords": "Separated flow, hypersonic flow, DSMC, reacting air, velocity slip", "note": "\u00a9 2016 AIP Publishing LLC. \n\nThe research is being performed at the University of Illinois Urbana-Champaign is supported by the Air Force Office of Scientific Research through AFOSR Grant No. FA9550-11-1-0129 with a subcontract award number 2010-06171-01 to UIUC. This research is also a part of the Blue Waters sustained-petascale computing project, which is supported by the National Science Foundation (awards OCI-0725070 and ACI-1238993) and the state of Illinois. Blue Waters is a joint effort of the University of Illinois at Urbana-Champaign and its National Center for Supercomputing Applications.\n\nPublished - 1.4967555.pdf
", "abstract": "The Direct Simulation Monte Carlo method has been used to model laminar shock wave boundary interactions of hypersonic flow over a 30/55-deg double-wedge and \"tick-shaped\" model configurations studied in the Hypervelocity Expansion Tube facility and T-ADFA free-piston shock tunnel, respectively. The impact of thermochemical effects on these interactions by changing the chemical composition from nitrogen to air as well as argon for a stagnation enthalpy of 8.0 MJ/kg flow are investigated using the 2-D wedge model. The simulations are found to reproduce many of the classic features related to Edney Type V strong shock interactions that include the attached, oblique shock formed over the first wedge, the detached bow shock from the second wedge, the separation zone, and the separation and reattachment shocks that cause complex features such as the triple point for both cases. However, results of a reacting air flow case indicate that the size of the separation length, and the movement of the triple point toward to the leading edge is much less than the nitrogen case.", "date": "2016-11-15", "date_type": "published", "publisher": "American Institute of Physics", "place_of_pub": "Melville, NY", "pagerange": "Art. No. 050005", "id_number": "CaltechAUTHORS:20170105-140420436", "isbn": "978-0-7354-1448-8", "book_title": "30th International Symposium on Rarefied Gas Dynamics", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170105-140420436", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-11-1-0129" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "2010-06171-01" }, { "agency": "NSF", "grant_number": "OCI-0725070" }, { "agency": "NSF", "grant_number": "ACI-1238993" }, { "agency": "State of Illinois" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Ketsdever-A", "name": { "family": "Ketsdever", "given": "Andrew" } }, { "id": "Struchup-H", "name": { "family": "Struchup", "given": "Henning" } } ] }, "doi": "10.1063/1.4967555", "primary_object": { "basename": "1.4967555.pdf", "url": "https://authors.library.caltech.edu/records/asfas-wqv51/files/1.4967555.pdf" }, "pub_year": "2016", "author_list": "Tumuklu, Ozgur; Levin, Deborah A.; et el." }, { "id": "https://authors.library.caltech.edu/records/b11ww-11n85", "eprint_id": 73102, "eprint_status": "archive", "datestamp": "2023-08-20 14:04:28", "lastmod": "2023-10-24 15:02:26", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bandyopadhyay-S", "name": { "family": "Bandyopadhyay", "given": "Saptarshi" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Hadaegh-F-Y", "name": { "family": "Hadaegh", "given": "Fred Y." } } ] }, "title": "A Probabilistic Eulerian Approach for Motion Planning of a Large-Scale Swarm of Robots", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2016 IEEE. \n\nDate Added to IEEE Xplore: 01 December 2016. \n\nThis research was supported in part by AFOSR grant FA95501210193 and NSF IIS 1253758. This research was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.", "abstract": "We present a novel method for guiding a large-scale swarm of autonomous agents into a desired formation shape in a distributed and scalable manner. Our Probabilistic Swarm Guidance using Inhomogeneous Markov Chains (PSG-IMC) algorithm adopts an Eulerian framework, where the physical space is partitioned into bins and the swarm's density distribution over each bin is controlled. Each agent determines its bin transition probabilities using a time-inhomogeneous Markov chain. These time-varying Markov matrices are constructed by each agent in real-time using the feedback from the current swarm distribution, which is estimated in a distributed manner. The PSG-IMC algorithm minimizes the expected cost of the transitions per time instant, required to achieve and maintain the desired formation shape, even when agents are added to or removed from the swarm. The algorithm scales well with a large number of agents and complex formation shapes. We demonstrate the effectiveness of this proposed swarm guidance algorithm by using results of numerical simulations and hardware experiments with multiple quadrotors.", "date": "2016-10", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "3822-3829", "id_number": "CaltechAUTHORS:20161221-142802182", "isbn": "978-1-5090-3761-2", "book_title": "2016 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161221-142802182", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA95501210193" }, { "agency": "NSF", "grant_number": "IIS-1253758" }, { "agency": "NASA/JPL/Caltech" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/IROS.2016.7759562", "pub_year": "2016", "author_list": "Bandyopadhyay, Saptarshi; Chung, Soon-Jo; et el." }, { "id": "https://authors.library.caltech.edu/records/gwm7t-v3507", "eprint_id": 71817, "eprint_status": "archive", "datestamp": "2023-08-20 13:53:21", "lastmod": "2023-10-23 17:13:41", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Burkel-B", "name": { "family": "Burkel", "given": "Brian" } }, { "id": "Lesman-A", "name": { "family": "Lesman", "given": "Ayelet" } }, { "id": "Rosakis-P", "name": { "family": "Rosakis", "given": "Phoebus" } }, { "id": "Tirrell-D-A", "name": { "family": "Tirrell", "given": "David A." }, "orcid": "0000-0003-3175-4596" }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "Guruswami" }, "orcid": "0000-0002-2912-0001" }, { "id": "Notbohm-J", "name": { "family": "Notbohm", "given": "Jacob" } } ] }, "title": "Microbuckling of Fibrous Matrices Enables Long Range Cell Mechanosensing", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Extracellular matrix \u2013 Mechanosensing \u2013 Fiber buckling \u2013 DVC \u2013 Traction force microscopy", "note": "\u00a9 2017 The Society for Experimental Mechanics, Inc. \n\nFirst Online: 21 September 2016. \n\nThis work was funded by grants from the National Science Foundation (Division of Materials Research 0520565 and 1206121) and from the California Institute for Regenerative Medicine (RB5-07398). J.N. was supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE-1144469. A.L. was supported in part by a Rothschild Foundation fellowship.", "abstract": "When biological cells migrate, divide, and invade, they push and pull on individual fibers of the matrix surrounding them. The resulting fiber displacements are neither uniform nor smooth; rather, displacements localize to form dense fibrous bands that span from one cell to another. It is thought that these bands may be a mechanism by which cells can sense their neighbors, but this hypothesis remains untested, because the mechanism for band formation remains unknown. Using digital volume correlation, we measure the displacements induced by contractile cells embedded in a fibrous matrix. We find that cell-induced displacements propagate over a longer range than predicted by linear elasticity. To explain the long-range propagation of displacements, we consider the effect of buckling of individual matrix fibers, which generates a nonlinear stress-strain relationship. We show that fiber buckling is the mechanism that causes the displacements to propagate over a long range and the bands to form between nearby cells. The results thus show that buckling of individual fibers provides a mechanism by which cells may sense their distant neighbors mechanically.", "date": "2016-09-21", "date_type": "published", "publisher": "Springer", "place_of_pub": "Cham", "pagerange": "135-141", "id_number": "CaltechAUTHORS:20161108-141109524", "isbn": "978-3-319-41350-1", "book_title": "Mechanics of Biological Systems and Materials", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161108-141109524", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "DMR-0520565" }, { "agency": "NSF", "grant_number": "DMR-1206121" }, { "agency": "California Institute for Regenerative Medicine", "grant_number": "RB5-07398" }, { "agency": "NSF Graduate Research Fellowship", "grant_number": "DGE-1144469" }, { "agency": "Rothschild Foundation Fellowship" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Korach-C-S", "name": { "family": "Korach", "given": "Chad S." } }, { "id": "Tekalur-S-A", "name": { "family": "Tekalur", "given": "Srinivasan Arjun" } }, { "id": "Zavattieri-P", "name": { "family": "Zavattieri", "given": "Pablo" } } ] }, "doi": "10.1007/978-3-319-41351-8_19", "pub_year": "2016", "author_list": "Burkel, Brian; Lesman, Ayelet; et el." }, { "id": "https://authors.library.caltech.edu/records/n9jzn-v0q21", "eprint_id": 71818, "eprint_status": "archive", "datestamp": "2023-08-20 13:53:24", "lastmod": "2023-10-23 17:13:46", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hsueh-Chun-Jen", "name": { "family": "Hsueh", "given": "Chun-Jen" } }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "Guruswami" }, "orcid": "0000-0002-2912-0001" }, { "id": "Bhattacharya-K", "name": { "family": "Bhattacharya", "given": "Kaushik" }, "orcid": "0000-0003-2908-5469" } ] }, "title": "Investigating the Effective Fracture Toughness of Heterogeneous Materials", "ispublished": "unpub", "full_text_status": "public", "keywords": "Fracture toughness \u2013 Heterogeneous materials \u2013 Surfing boundary conditions \u2013 Grid method \u2013 Brittle materials", "note": "\u00a9 2017 Springer International Publishing.", "abstract": "Heterogeneous materials are ubiquitous in nature, and are increasingly being engineered to obtain desirable mechanical properties. Naturally, the bulk properties of a heterogeneous material can be different from those of its constituents. Thus, one needs to determine its overall or effective properties. For some of these properties, like effective elastic modulus, the characterization is well-known, while for other such as effective fracture toughness, it is a matter of ongoing research. In this paper, we present a method to measure the effective fracture toughness. For the method, we apply a time-dependent displacement condition called the surfing boundary condition. This boundary condition leads the crack to propagate steadily macroscopically but in an unconstrained manner microscopically. We then use the grid method, a non-contact full-field displacement measurement technique, to obtain the displacement gradient. With this field, we compute the macroscopic energy release rate via the area J-integral. Finally, we interpret the effective toughness as the peak of the energy release rate. Using this method, we investigate the influence of heterogeneity on effective fracture toughness. We find that the effective toughness can be enhanced due to the heterogeneity. Consequently, engineered heterogeneity may provide a means to improve fracture toughness in solids.", "date": "2016-09-21", "date_type": "published", "publisher": "Springer", "place_of_pub": "Cham", "pagerange": "15-20", "id_number": "CaltechAUTHORS:20161108-142119224", "isbn": "978-3-319-42194-0", "book_title": "Fracture, Fatigue, Failure and Damage Evolution", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161108-142119224", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Zehnder-A-T", "name": { "family": "Zehnder", "given": "Alan T." } }, { "id": "Carroll-J", "name": { "family": "Carroll", "given": "Jay" } }, { "id": "Hazeli-K", "name": { "family": "Hazeli", "given": "Kavan" } }, { "id": "Swain-L", "name": { "family": "Swain", "given": "Lesia" } }, { "id": "Pataky-G", "name": { "family": "Pataky", "given": "Garrett" } } ] }, "doi": "10.1007/978-3-319-42195-7_3", "pub_year": "2016", "author_list": "Hsueh, Chun-Jen; Ravichandran, Guruswami; et el." }, { "id": "https://authors.library.caltech.edu/records/wx4w9-3wm64", "eprint_id": 71819, "eprint_status": "archive", "datestamp": "2023-08-20 13:50:44", "lastmod": "2023-10-23 17:13:49", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Wojnar-C-S", "name": { "family": "Wojnar", "given": "Charles S." } }, { "id": "le-Graverend-J-B", "name": { "family": "le Graverend", "given": "Jean-Briac" } }, { "id": "Kochmann-D-M", "name": { "family": "Kochmann", "given": "Dennis M." }, "orcid": "0000-0002-9112-6615" } ] }, "title": "Broadband Electromechanical Spectroscopy: A Method for Measuring the Dynamic Electromechanical Response of Ferroelectrics", "ispublished": "unpub", "full_text_status": "public", "keywords": "Dynamic mechanical analysis \u2013 Electromechanical loading \u2013 Ferroelectricity \u2013 Lead zirconate titanate \u2013 Viscoelasticity", "note": "\u00a9 2017 Springer International Publishing.", "abstract": "To gain a better understanding of the dynamic response of thermo-electro-mechanically coupled materials, in particular stiffness and mechanical damping, an experimental apparatus and method called Broadband Electromechanical Spectroscopy (BES) has been developed. The motivation for creating BES was to study the behavior of ferroelectric materials (and other electro-active materials) over wide ranges of frequencies of simultaneously-applied electric fields and mechanical stresses under accurate temperature control. By precisely controlling electric fields and mechanical loading, the effect of microstructural changes, in particular domain switching in ferroelectrics, on the material's dynamic mechanical response is measured. Experiments show large increases in mechanical damping during domain switching that can be tuned by appropriate electrical loading. Results obtained using the new capabilities brought by BES can be used to better understand the damping associated with domain wall motion to be able to create ceramic materials with both high stiffness and high damping\u2014an elusive combination of properties in typical engineering materials. The design and use of the apparatus along with results obtained from tests on a particular ferroelectric, viz. lead zirconate titanate, are presented.", "date": "2016-09-17", "date_type": "published", "publisher": "Springer", "place_of_pub": "Cham", "pagerange": "63-71", "id_number": "CaltechAUTHORS:20161108-143159836", "isbn": "978-3-319-42227-5", "book_title": "Micro and Nanomechanics", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161108-143159836", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Starman-L-V-A", "name": { "family": "Starman", "given": "La Vern A." } }, { "id": "Hay-J", "name": { "family": "Hay", "given": "Jennifer" } }, { "id": "Karanjgaokar-N", "name": { "family": "Karanjgaokar", "given": "Nikhil" } } ] }, "doi": "10.1007/978-3-319-42228-2_10", "pub_year": "2016", "author_list": "Wojnar, Charles S.; le Graverend, Jean-Briac; et el." }, { "id": "https://authors.library.caltech.edu/records/a5rwj-28k75", "eprint_id": 83949, "eprint_status": "archive", "datestamp": "2023-08-20 13:39:56", "lastmod": "2023-10-18 14:33:03", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Falcone-G", "name": { "family": "Falcone", "given": "Giusy" } }, { "id": "Saxena-Ayush", "name": { "family": "Saxena", "given": "Ayush" } }, { "id": "Bandyopadhyay-S", "name": { "family": "Bandyopadhyay", "given": "Saptarshi" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Hadaegh-F-Y", "name": { "family": "Hadaegh", "given": "Fred" } } ] }, "title": "Attitude Control of the Asteroid Redirect Robotic Mission Spacecraft with a Captured Boulder", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2016 AIAA.", "abstract": "NASA's Asteroid Redirect Robotic Mission (ARRM) aims to pick up a boulder from of a large asteroid and transport it to a distant retrograde orbit around the Moon for future exploration by a manned mission. In this paper, we present a detailed analysis for one of the main control challenges in ARRM, i.e., three-axis attitude control of the ARRM spacecraft with the captured boulder in the presence of large uncertainties in the physical model of the boulder. We first present a 30 degree-of-freedom nonlinear dynamic model of the ARRM spacecraft and boulder combination. We then linearize this nonlinear model about the nominal operating conditions to study the system's modal properties. A finite element model of the ARRM spacecraft and boulder combination is used to validate our model. We then present linear and nonlinear control laws for the attitude control problem. Both the proportional-derivate based linear controller with lead-lag compensator and roll-off filter and the robust nonlinear tracking control law that tracks a derivative plus proportional-derivate based desired attitude trajectory give robust performance over the range of boulder parameters. We present a detailed comparison of these control laws and also present some design guidelines for the ARRM spacecraft.", "date": "2016-09", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "pagerange": "Art. No. 2016-5645", "id_number": "CaltechAUTHORS:20171218-083612231", "isbn": "978-1-62410-445-9", "book_title": "AIAA/AAS Astrodynamics Specialist Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171218-083612231", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2016-5645", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2016-5645", "pub_year": "2016", "author_list": "Falcone, Giusy; Saxena, Ayush; et el." }, { "id": "https://authors.library.caltech.edu/records/8xnyw-9zt91", "eprint_id": 83914, "eprint_status": "archive", "datestamp": "2023-08-20 13:39:53", "lastmod": "2023-10-18 14:30:29", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Foust-Rebecca", "name": { "family": "Foust", "given": "Rebecca C." }, "orcid": "0000-0003-1470-1716" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Hadaegh-F-Y", "name": { "family": "Hadaegh", "given": "Fred Y." } } ] }, "title": "Autonomous In-Orbit Satellite Assembly from a Modular Heterogeneous Swarm using Sequential Convex Programming", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2016 American Institute of Aeronautics and Astronautics.", "abstract": "This paper presents a decentralized guidance and control scheme to combine a heterogeneous swarm of component satellites into a large satellite structure. Building on prior work, the Swarm Orbital Construction Algorithm was made more realistic and correct by changing the docking and collision avoidance criteria and implementing a nonlinear correction in the convex optimization solver. The algorithm was then extended to function in a simulated perturbed 6-DOF spacecraft environment. This required the addition of an attitude barrier function to the target assignment algorithm as discussed in the previous paper, as well as the selection of a realistic range for actuator performance and spacecraft shape parameters. Simulation results are presented using a swarm of CubeSat-class satellites.", "date": "2016-09", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "pagerange": "Art. No. 2016-5271", "id_number": "CaltechAUTHORS:20171214-075651822", "isbn": "978-1-62410-445-9", "book_title": "AIAA/AAS Astrodynamics Specialist Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171214-075651822", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2016-5271", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2016-5271", "pub_year": "2016", "author_list": "Foust, Rebecca C.; Chung, Soon-Jo; et el." }, { "id": "https://authors.library.caltech.edu/records/1pv9c-acf52", "eprint_id": 83950, "eprint_status": "archive", "datestamp": "2023-08-20 13:39:59", "lastmod": "2023-10-18 14:33:06", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Baldini-F", "name": { "family": "Baldini", "given": "Francesca" } }, { "id": "Bandyopadhyay-S", "name": { "family": "Bandyopadhyay", "given": "Saptarshi" } }, { "id": "Foust-Rebecca", "name": { "family": "Foust", "given": "Rebecca" }, "orcid": "0000-0003-1470-1716" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Rahmani-A", "name": { "family": "Rahmani", "given": "Amir" } }, { "id": "de-la-Croix-J-P", "name": { "family": "de la Croix", "given": "Jean-Pierre" } }, { "id": "Bacula-A", "name": { "family": "Bacula", "given": "Alexandra" } }, { "id": "Chilan-Christian-M", "name": { "family": "Chilan", "given": "Christian M." } }, { "id": "Hadaegh-F-Y", "name": { "family": "Hadaegh", "given": "Fred" } } ] }, "title": "Fast Motion Planning for Agile Space Systems with Multiple Obstacles", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2016 AIAA.", "abstract": "In this paper, we develop a novel algorithm for spacecraft trajectory planning in an environment cluttered with many geometrically-fixed obstacles. The Spherical Expansion and Sequential Convex Programming (SE-SCP) algorithm first uses a spherical-expansion-based sampling algorithm to explore the workspace. Once a path is found from the start position to the goal position, the algorithm generates a locally optimal trajectory within the homotopy class using sequential convex programming. If the number of samples tends to infinity, then the SE-SCP trajectory converges to the globally optimal trajectory in the workspace. The SE-SCP algorithm is computationally efficient, therefore it can be used for real-time applications on resource-constrained systems. We also present results of numerical simulations and comparisons with existing algorithms.", "date": "2016-09", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "pagerange": "Art. No. 2016-5683", "id_number": "CaltechAUTHORS:20171218-084716717", "isbn": "978-1-62410-445-9", "book_title": "AIAA/AAS Astrodynamics Specialist Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171218-084716717", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2016-5683", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2016-5683", "pub_year": "2016", "author_list": "Baldini, Francesca; Bandyopadhyay, Saptarshi; et el." }, { "id": "https://authors.library.caltech.edu/records/cajw4-02975", "eprint_id": 78747, "eprint_status": "archive", "datestamp": "2023-08-20 13:32:41", "lastmod": "2024-01-13 20:29:26", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kochmann-D-M", "name": { "family": "Kochmann", "given": "Dennis M." }, "orcid": "0000-0002-9112-6615" }, { "id": "Amelang-J-S", "name": { "family": "Amelang", "given": "Jeffrey S." } } ] }, "title": "The Quasicontinuum Method: Theory and Applications", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2016 Springer International Publishing Switzerland. \n\nFirst Online: 31 August 2016.\n\nThe authors gratefully acknowledge support from the National Science Foundation (NSF) under grant number CMMI-123436.", "abstract": "The quasicontinuum (QC) method has become a popular technique to bridge the gap between atomistic and continuum length scales in crystalline solids. In contrast to many other concurrent scale-coupling methods, the QC method only relies upon constitutive information on the lowest scale (viz., on interatomic potentials) and thus avoids empirical constitutive laws at the larger scales. This is achieved by the application of a seamless coarse-graining scheme to the discrete atomistic ensemble and the careful selection of a small set of representative atoms. Since its inception almost two decades ago, many different variants and flavors of the QC method have been developed, not only to study the mechanics of solids but also to describe such physical phenomena as mass and heat transfer, or to efficiently describe fiber networks and truss structures. Here, we review the theoretical fundamentals and give a (non-exhaustive) overview of the state of the art in QC theory, computational methods, and applications. We particularly emphasize the fully nonlocal QC formulation which adaptively ties atomistic resolution to moving defects, and we illustrate simulation results based on this framework. Finally, we point out challenges and open questions associated with the QC methodology.", "date": "2016-08-31", "date_type": "published", "publisher": "Springer", "place_of_pub": "Cham, Switzerland", "pagerange": "159-193", "id_number": "CaltechAUTHORS:20170705-075708170", "isbn": "978-3-319-33478-3", "book_title": "Multiscale Materials Modeling for Nanomechanics", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170705-075708170", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "CMMI-123436" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Weinberger-C-R", "name": { "family": "Weinberger", "given": "Christopher R." } }, { "id": "Tucker-G-J", "name": { "family": "Tucker", "given": "Garritt J." } } ] }, "doi": "10.1007/978-3-319-33480-6_5", "pub_year": "2016", "author_list": "Kochmann, Dennis M. and Amelang, Jeffrey S." }, { "id": "https://authors.library.caltech.edu/records/h6fhh-w7991", "eprint_id": 70657, "eprint_status": "archive", "datestamp": "2023-08-20 13:01:40", "lastmod": "2024-01-13 16:53:53", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Jackson-K", "name": { "family": "Jackson", "given": "Kate" } }, { "id": "Wallace-J-K", "name": { "family": "Wallace", "given": "J. K." } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Co-phasing primary mirror segments of an optical space telescope using a long stroke Zernike WFS", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2016 Society of Photo-Optical Instrumentation Engineers (SPIE).\n\nThis work was funded in part by the Spontaneous Research and Technology Development fund at the Jet Propulsion Laboratory. This work was partially carried out by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.\n\nPublished - 99046D.pdf
", "abstract": "Static Zernike phase-contrast plates have been used extensively in microscopy for half a century and, more recently, in optical telescopes for wavefront sensing. A dynamic Zernike wavefront sensor (WFS) with four phase shifts, for reducing error due to spurious light and eliminating other asynchronous noise, has been proposed for use in adaptive optics. Here, we propose adapting this method for co-phasing the primary mirror of a segmented space telescope. In order to extend the dynamic range of the WFS, which has a maximum range of +/ \u2212 \u03bb/2, a phase- contrast plate with multiple steps, both positive and negative, has been developed such that errors as large as +/ \u2212 10\u03bb can be sensed. The manufacturing tolerances have been incorporated into simulations, which demonstrate that performance impacts are minimal. We show that the addition of this small optical plate along with a high precision linear translation stage at the prime focus of a telescope and pupil viewing capability can provide extremely accurate segment phasing with a simple white-light fringe fitting algorithm and a closed-loop controller. The original focal-plane geometry of a centro-symmetric phase shifting element is replaced with a much less constrained shape, such as a slot. Also, a dedicated pupil imager is not strictly required; an existing pupil sampler such as a Shack-Hartmann (SH) WFS can be used just as effectively, allowing simultaneous detection of wavefront errors using both intensity and spot positions on the SH-WFS. This could lead to an efficient synergy between Zernike and SH-WFS, enabling segment phasing in conjunction with high-dynamic range sensing.", "date": "2016-07-29", "date_type": "published", "publisher": "Society of Photo-Optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "Art. No. 99046D", "id_number": "CaltechAUTHORS:20160929-095806840", "isbn": "9781510601871", "book_title": "Space Telescopes and Instrumentation 2016: Optical, Infrared, and Millimeter Wave", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160929-095806840", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "JPL Research and Technology Development Fund" }, { "agency": "NASA/JPL/Caltech" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "MacEwen-H-A", "name": { "family": "MacEwen", "given": "Howard A." } }, { "id": "Fazio-G-G", "name": { "family": "Fazio", "given": "Giovanni G." } }, { "id": "Lystrup-M", "name": { "family": "Lystrup", "given": "Makenzie" } }, { "id": "Batalha-N-M", "name": { "family": "Batalha", "given": "Natalie" } }, { "id": "Siegler-N", "name": { "family": "Siegler", "given": "Nick" } }, { "id": "Tong-Edward-C", "name": { "family": "Tong", "given": "Edward C." } } ] }, "doi": "10.1117/12.2249638", "primary_object": { "basename": "99046D.pdf", "url": "https://authors.library.caltech.edu/records/h6fhh-w7991/files/99046D.pdf" }, "pub_year": "2016", "author_list": "Jackson, Kate; Wallace, J. K.; et el." }, { "id": "https://authors.library.caltech.edu/records/3dasg-wte70", "eprint_id": 70658, "eprint_status": "archive", "datestamp": "2023-08-20 12:56:56", "lastmod": "2023-10-20 23:18:17", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Steeves-J", "name": { "family": "Steeves", "given": "John" } }, { "id": "Jackson-K", "name": { "family": "Jackson", "given": "Kathryn" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" }, { "id": "Redding-D", "name": { "family": "Redding", "given": "David" } }, { "id": "Wallace-J-K", "name": { "family": "Wallace", "given": "J. Kent" } }, { "id": "Bradford-S-C", "name": { "family": "Bradford", "given": "Samuel Case" } }, { "id": "Barbee-T", "name": { "family": "Barbee", "given": "Troy" } } ] }, "title": "Multilayer Active Shell Mirrors for Space Telescopes", "ispublished": "unpub", "full_text_status": "public", "keywords": "Active Mirrors, CFRP, Nanolaminate, Replication, Reverse Hartmann", "note": "\u00a9 2016 Society of Photo-Optical Instrumentation Engineers (SPIE). \n\nA part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology under a contract with the National Aeronautics and Space Administration (NASA).\n\nPublished - 99121K.pdf
", "abstract": "A novel active mirror technology based on carbon fiber reinforced polymer (CFRP) substrates and replication techniques has been developed. Multiple additional layers are implemented into the design serving various functions. Nanolaminate metal films are used to provide a high quality reflective front surface. A backing layer of thin active material is implemented to provide the surface-parallel actuation scheme. Printed electronics are used to create a custom electrode pattern and flexible routing layer. Mirrors of this design are thin (< 1.0 mm), lightweight (2.7 kg/m^2), and have large actuation capabilities. These capabilities, along with the associated manufacturing processes, represent a significant change in design compared to traditional optics. Such mirrors could be used as lightweight primaries for small CubeSat-based telescopes or as meter-class segments for future large aperture observatories. Multiple mirrors can be produced under identical conditions enabling a substantial reduction in manufacturing cost and complexity. \n\nAn overview of the mirror design and manufacturing processes is presented. Predictions on the actuation performance have been made through finite element simulations demonstrating correctabilities on the order of 250-300\u00d7 for astigmatic modes with only 41 independent actuators. A description of the custom metrology system used to characterize the active mirrors is also presented. The system is based on a Reverse Hartmann test and can accommodate extremely large deviations in mirror figure (> 100 \u03bcm PV) down to sub-micron precision. The system has been validated against several traditional techniques including photogrammetry and interferometry. The mirror performance has been characterized using this system, as well as closed-loop figure correction experiments on 150 mm dia. prototypes. The mirrors have demonstrated post-correction figure accuracies of 200 nm RMS (two dead actuators limiting performance).", "date": "2016-07-22", "date_type": "published", "publisher": "Society of Photo-Optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "Art. No. 99121K", "id_number": "CaltechAUTHORS:20160929-102853368", "isbn": "9781510602038", "book_title": "Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation II", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160929-102853368", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Navarro-R", "name": { "family": "Navarro", "given": "Ram\u00f3n" } }, { "id": "Burge-J-H", "name": { "family": "Burge", "given": "James H." } } ] }, "doi": "10.1117/12.2233594", "primary_object": { "basename": "99121K.pdf", "url": "https://authors.library.caltech.edu/records/3dasg-wte70/files/99121K.pdf" }, "pub_year": "2016", "author_list": "Steeves, John; Jackson, Kathryn; et el." }, { "id": "https://authors.library.caltech.edu/records/t4k67-kbw24", "eprint_id": 98104, "eprint_status": "archive", "datestamp": "2023-08-20 12:57:13", "lastmod": "2023-10-18 17:03:19", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Costantino-A-M", "name": { "family": "Costantino", "given": "Adrian M." } }, { "id": "Narsai-P-S", "name": { "family": "Narsai", "given": "Pavan S." } }, { "id": "Cantwell-B-J", "name": { "family": "Cantwell", "given": "Brian J." } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Nondestructive Mapping of Hybrid Rocket Fuel Grains", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2016 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 22 Jul 2016. \n\nA. M. Costantino would like to thank the Summer Undergraduate Research Fellowship (SURF) with the aid of the donation from Mary P. and Dean C. Daily and funding from the Stanford aerospace and Astronautics Department. I also thank Stanford graduate student Pavan Narsai who guided and assisted me in my research over the course of the program as well as Javier Stober and Alexandra Ilic for their help in machining parts of the measuring device.", "abstract": "The regression rates of solid fuels used in hybrid rocket motors are a critical parameter in the design and development of hybrid propulsion systems. Currently, it is difficult to measure fuel geometries accurately, thus causing difficulties in accurately describing regression rates, especially for smaller scale systems. Nondestructive techniques can solve this problem, as it is not necessary to get tooling into the ports. An apparatus that maps the fuel grain employing an immersed ultrasound transducer has been manufactured; its results will be the primary focus of this study. The full geometry of the fuel grains can be generated pre and post fire, which may lead to greater understanding of the way hybrid rocket fuels burn. Furthermore, previously undetectable defects, such as cracks and voids, may be identified. The study found that the method used to cast the fuel grains, spin casting causes thinning in wall thickness on average of 11.3% with a standard deviation of 1.2% from the end to the middle of the fuel grain. The generated data can further validate proposed analytical solutions (Cantwell, 2014) to the regression rate equations (Marxman and Gilbert, 1963) associated with hybrid rocket propulsion systems.", "date": "2016-07-22", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2016-4866", "id_number": "CaltechAUTHORS:20190822-102905667", "isbn": "978-1-62410-406-0", "book_title": "52nd AIAA/SAE/ASEE Joint Propulsion Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190822-102905667", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech Summer Undergraduate Research Fellowship (SURF)" }, { "agency": "Mary P. and Dean C. Daily" }, { "agency": "Stanford University" } ] }, "other_numbering_system": { "items": [ { "id": "2016-4866", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2016-4866", "pub_year": "2016", "author_list": "Costantino, Adrian M.; Narsai, Pavan S.; et el." }, { "id": "https://authors.library.caltech.edu/records/dyqqt-9ac14", "eprint_id": 98273, "eprint_status": "archive", "datestamp": "2023-08-20 12:57:16", "lastmod": "2023-10-18 17:12:40", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Yanes-N-J", "name": { "family": "Yanes", "given": "Nelson J." } }, { "id": "Guerrero-Vala-P", "name": { "family": "Guerrero-Vala", "given": "Pablo" } }, { "id": "Friss-A-J", "name": { "family": "Friss", "given": "Adam J." } }, { "id": "Polk-J-E", "name": { "family": "Polk", "given": "James E." } }, { "id": "Jorns-B-A", "name": { "family": "Jorns", "given": "Benjamin A." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "Joanna" }, "orcid": "0000-0003-3129-5035" } ] }, "title": "Ion Acoustic Turbulence and Ion Energy Measurements in the Plume of the HERMeS Thruster Hollow Cathode", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2016 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 22 Jul 2016.", "abstract": "Hollow cathodes serve as the electron source in ion and Hall thrusters. One of the life limiting factors of the propulsion system is cathode failure due to erosion from high energy ion bombardment. Despite the successful application of hollow cathodes on commercial and deep-space missions, the fundamental physical processes of erosion are not fully understood, particularly the source of the high energy ions. A recent experimental study of the near-plume in a high current hollow cathode confirmed the existence of ion acoustic turbulence (IAT), a phenomenon that was only previously suspected and modeled in numerical simulations. Theoretical analyses and turbulence measurements in the plume established that ion acceleration due to turbulence could explain the existence of high energy ions. This paper is a continuation of this work, focusing on detecting and quantifying instabilities in the cathode near-plume under conditions relevant for the thruster being developed for the proposed Asteroid Robotic Redirect Mission (ARRM). Ion acoustic turbulence and ion energy measurements were taken at the nominal discharge currents and cathode flow rates expected for ARRM, as well as off-nominal conditions to determine where it might be susceptible to erosion by high energy ions. Dual ion saturation probes were used to measure fluctuations in ion saturation current and assess the wave dispersion relation. A retarding potential energy analyzer was used to measure ion energy distribution functions for ions with velocities perpendicular to the plume flow. The effect of cathode orifice size on the onset of IAT has also been studied. Peaks in wave amplitude were found at extremely low flow rates and high discharge currents, where instabilities other than IAT dominate. In addition, the onset of IAT was found to occur at discharge currents as low as 35 A. Measurements also confirm that at high discharge currents above 30 A, a larger orifice size reduces the magnitude of turbulence. However, large orifices are more susceptible to low frequency instabilities at flow rates below 10 sccm.", "date": "2016-07-22", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2016-5028", "id_number": "CaltechAUTHORS:20190827-112625219", "isbn": "978-1-62410-406-0", "book_title": "52nd AIAA/SAE/ASEE Joint Propulsion Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190827-112625219", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2016-5028", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2016-5028", "pub_year": "2016", "author_list": "Yanes, Nelson J.; Guerrero-Vala, Pablo; et el." }, { "id": "https://authors.library.caltech.edu/records/3880g-c5e82", "eprint_id": 72514, "eprint_status": "archive", "datestamp": "2023-08-20 12:53:55", "lastmod": "2024-01-13 20:21:06", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Dunne-R", "name": { "family": "Dunne", "given": "Reeve" } }, { "id": "Tsai-Hsieh-Chen", "name": { "family": "Tsai", "given": "Hsieh-Chen" } }, { "id": "Colonius-T", "name": { "family": "Colonius", "given": "Tim" }, "orcid": "0000-0003-0326-3909" }, { "id": "McKeon-B-J", "name": { "family": "McKeon", "given": "Beverley J." }, "orcid": "0000-0003-4220-1583" } ] }, "title": "Leading Edge Vortex Development on Pitching and Surging Airfoils: A Study of Vertical Axis Wind Turbines", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2016 Springer International Publishing Switzerland. \n\nFirst Online: 19 July 2016. \n\nThis work was supported by the Gordon and Betty Moore Foundation through grant GBMF#2645 to the California Institute of Technology.", "abstract": "Vertical axis wind turbine blades undergo dynamic stall due to the large angle of attack variation they experience during a turbine rotation. Particle image velocimetry on a pitching and surging airfoil was used to perform time resolved measurements at blade Reynolds numbers near turbine operating conditions of 10^5. These experiments were compared to simulations performed in the rotating turbine frame as well as the linear, experimental, frame at a Reynolds number of 10^3 to investigate rotational and Reynolds number effects. The flow was shown to develop similarly prior to separation, but the kinematics of vortices shed post separation were reference frame dependent.", "date": "2016-07-19", "date_type": "published", "publisher": "Springer", "place_of_pub": "Cham", "pagerange": "581-587", "id_number": "CaltechAUTHORS:20161202-082406384", "isbn": "978-3-319-30600-1", "book_title": "Proceedings of the 5th International Conference on Jets, Wakes and Separated Flows (ICJWSF2015)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161202-082406384", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gordon and Betty Moore Foundation", "grant_number": "2645" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Segalini-A", "name": { "family": "Segalini", "given": "Antonio" } } ] }, "doi": "10.1007/978-3-319-30602-5_71", "pub_year": "2016", "author_list": "Dunne, Reeve; Tsai, Hsieh-Chen; et el." }, { "id": "https://authors.library.caltech.edu/records/q3prp-ak720", "eprint_id": 72331, "eprint_status": "archive", "datestamp": "2023-09-15 05:34:13", "lastmod": "2023-10-23 21:19:11", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "McKeon-B-J", "name": { "family": "McKeon", "given": "B. J." }, "orcid": "0000-0003-4220-1583" }, { "id": "Hufstedler-E-A-L", "name": { "family": "Hufstedler", "given": "Esteban A. L." }, "orcid": "0000-0001-7162-920X" } ] }, "title": "Isolated Gust Generation for the Investigation of Airfoil-Gust Interaction", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2016 AIAA. \n\nThis research is funded by the Gordon and Betty Moore Foundation through Grant GBMF#2645 to the California Institute of Technology\n\nAccepted Version - HufstedlerMcKeon-AIAA-Aviation-2016.pdf
", "abstract": "As part of an effort to examine the impact of vortical gusts on airfoils, a simple gust\ngenerator has been built and investigated. This consists of a heaving \nat plate capable of\nfollowing a specifed transverse trajectory across a water tunnel. The relationship between\nthe trajectory and the properties of the gusts that are shed downstream is characterized\nfor non-periodic heaving motion described by Eldredge's smooth motion equation. PIV\nexperiments show that the circulation of the vortical gust is proportional to the heaving\nspeed of the plate. Tests with a downstream NACA 0018 airfoil demonstrate repeatable\nforces in response to the produced gusts.", "date": "2016-06-13", "date_type": "published", "publisher": "AIAA", "id_number": "CaltechAUTHORS:20161128-141948592", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161128-141948592", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gordon and Betty Moore Foundation", "grant_number": "GBMF2645" } ] }, "other_numbering_system": { "items": [ { "id": "2016-4257", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2016-4257", "primary_object": { "basename": "HufstedlerMcKeon-AIAA-Aviation-2016.pdf", "url": "https://authors.library.caltech.edu/records/q3prp-ak720/files/HufstedlerMcKeon-AIAA-Aviation-2016.pdf" }, "pub_year": "2016", "author_list": "McKeon, B. J. and Hufstedler, Esteban A. L." }, { "id": "https://authors.library.caltech.edu/records/t8tds-qan82", "eprint_id": 72332, "eprint_status": "archive", "datestamp": "2023-08-20 11:54:29", "lastmod": "2023-10-23 21:38:37", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Rosenberg-Kevin-T", "name": { "family": "Rosenberg", "given": "Kevin" } }, { "id": "Duvvuri-S", "name": { "family": "Duvvuri", "given": "Subrahmanyam" }, "orcid": "0000-0001-8082-1658" }, { "id": "Luhar-M", "name": { "family": "Luhar", "given": "Mitul" } }, { "id": "McKeon-B-J", "name": { "family": "McKeon", "given": "Beverley J." }, "orcid": "0000-0003-4220-1583" }, { "id": "Barnard-C", "name": { "family": "Barnard", "given": "Casey" } }, { "id": "Friedkes-B", "name": { "family": "Freidkes", "given": "Brett" } }, { "id": "Meloy-J", "name": { "family": "Meloy", "given": "Jessica" } }, { "id": "Sheplak-M", "name": { "family": "Sheplak", "given": "Mark" } } ] }, "title": "Phase relationships between velocity, wall pressure, and wall shear stress in a forced turbulent boundary layer", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2016 AIAA. \n\nThe support of AFOSR (grant FA 9550-12-1-0469, program manager D. Smith) is gratefully acknowledged.\n\nAccepted Version - KRosenberg_aiaa_aviation_final_manuscript.pdf
", "abstract": "A large scale spatio-temporally periodic disturbance was excited in a turbulent boundary\nlayer via a wall-actuated dynamic roughness. Streamwise velocity, wall pressure, and direct\nwall shear stress measurements were made with a hot wire, pressure microphone, and a\nmicro-scale differential capacitive sensor, respectively. Phase-averaged fields for the three\nquantities were calculated and analyzed. A phase calibration between the various sensors\nwas performed with an acoustic plane wave tube over a range of operating conditions\nto validate a direct phase comparison between the respective quantities. Results suggest\nencouraging agreement between the phase of the wall shear stress and velocity near the wall;\nhowever, more refined velocity measurements are needed to make quantitative comparisons\nto the wall pressure. Overall, this work highlights the potential for wall-based control with\napplications towards reducing turbulent drag.", "date": "2016-06", "date_type": "published", "publisher": "AIAA", "id_number": "CaltechAUTHORS:20161128-143308353", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161128-143308353", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA 9550-12-1-0469" } ] }, "other_numbering_system": { "items": [ { "id": "2016-4396", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2016-4396", "primary_object": { "basename": "KRosenberg_aiaa_aviation_final_manuscript.pdf", "url": "https://authors.library.caltech.edu/records/t8tds-qan82/files/KRosenberg_aiaa_aviation_final_manuscript.pdf" }, "pub_year": "2016", "author_list": "Rosenberg, Kevin; Duvvuri, Subrahmanyam; et el." }, { "id": "https://authors.library.caltech.edu/records/1a1ay-nks39", "eprint_id": 70373, "eprint_status": "archive", "datestamp": "2023-08-20 11:53:37", "lastmod": "2023-10-20 22:53:33", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Cymbalist-N", "name": { "family": "Cymbalist", "given": "Niccolo" } }, { "id": "Candler-G-V", "name": { "family": "Candler", "given": "Graham V." } }, { "id": "Dimotakis-P-E", "name": { "family": "Dimotakis", "given": "Paul E." } } ] }, "title": "Application of the Evolution-Variable Manifold Approach to Cavity-Stabilized Ethylene Combustion", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2016 AIAA.\n\nThis work was sponsored by the Air Force Office of Scientific Research under grant FA9550-12-1-0461.\nThe views and conclusions contained herein are those of the author and should not be interpreted as necessarily\nrepresenting the official policies or endorsements, either expressed or implied, of the AFOSR or the\nU.S. Government.\n\nWe would also like to thank Prof. Mirko Gamba of the University of Michigan for providing the code\nto compute the synthetic OH PLIF signal plots (Fig. 7), Drs. Matthew Bartkowicz and Travis Drayna of\nGoHypersonic Inc. for generating the grids used in this work, and Mr. Anand Kartha of the University of\nMinnesota for providing synthetic turbulent in\now code used for the University of Virginia simulations.\n\nPublished - Cymbalist_CD.2016.AIAAP.Application_of_the_EVM_Approach_to_Cavity-Stabilized_Ethylene_Combustion.pdf
", "abstract": "For combustion in high-speed flows, radical-formation time scales and ignition delay times may be similar to, or dominate, relevant flow time scales. Reliable modeling of induction and autoignition processes is critical to the prediction of combustor performance. The evolution-variable manifold (EVM) approach of Cymbalist and Dimotakis uses a transported scalar to track the evolution of the reaction processes, from induction leading to autoignition and subsequent robust combustion. In the present work, the EVM method is implemented in a computational \nfluid dynamics code in which wall-modeled large-eddy\nsimulations are performed for two ethylene-air high-speed combustion cases. The detailed thermochemical state of the reacting fluid is tabulated as a function of a reduced number of state variables that include density, energy, mixture fraction, and the reaction-evolution variable. A thermodynamically consistent numerical flux function is developed and the approach for coupling the large-eddy simulation to the EVM framework is discussed. It is found that particular attention must be given to the solution of the energy equation to obtain accurate and computationally stable results. The results show that the LES-EVM approach shows promise for the simulation of turbulent combustion of hydrocarbons in high-speed flows, including those dominated by ignition delay, and encompass regions of thin reaction fronts as well as distributed reaction zones.", "date": "2016-06", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics (AIAA)", "place_of_pub": "Reston, VA", "pagerange": "Paper No.AIAA-2016-3481", "id_number": "CaltechAUTHORS:20160915-105801877", "isbn": "9781624104367", "book_title": "46th AIAA Fluid Dynamics Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160915-105801877", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-12-1-0461" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2016-3481", "primary_object": { "basename": "Cymbalist_CD.2016.AIAAP.Application_of_the_EVM_Approach_to_Cavity-Stabilized_Ethylene_Combustion.pdf", "url": "https://authors.library.caltech.edu/records/1a1ay-nks39/files/Cymbalist_CD.2016.AIAAP.Application_of_the_EVM_Approach_to_Cavity-Stabilized_Ethylene_Combustion.pdf" }, "pub_year": "2016", "author_list": "Cymbalist, Niccolo; Candler, Graham V.; et el." }, { "id": "https://authors.library.caltech.edu/records/hcndr-5e639", "eprint_id": 87994, "eprint_status": "archive", "datestamp": "2023-08-20 11:43:57", "lastmod": "2024-01-14 20:28:41", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Brockers-R", "name": { "family": "Brockers", "given": "R." } }, { "id": "Fragoso-A", "name": { "family": "Fragoso", "given": "A." } }, { "id": "Matthies-L", "name": { "family": "Matthies", "given": "L." } } ] }, "title": "Stereo vision-based obstacle avoidance for micro air vehicles using an egocylindrical image space representation", "ispublished": "unpub", "full_text_status": "public", "keywords": "Micro air vehicles, obstacle avoidance, vision, egocylinder", "note": "\u00a9 2016 Society of Photo-optical Instrumentation Engineers (SPIE).\n\nThis work was funded by the Army Research Laboratory under the Micro Autonomous Systems & Technology Collaborative Technology Alliance program (MAST-CTA). JPL contributions were carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.\n\nPublished - 98361R.pdf
", "abstract": "Micro air vehicles which operate autonomously at low altitude in cluttered environments require a method for onboard obstacle avoidance for safe operation. Previous methods deploy either purely reactive approaches, mapping low-level visual features directly to actuator inputs to maneuver the vehicle around the obstacle, or deliberative methods that use on-board 3-D sensors to create a 3-D, voxel-based world model, which is then used to generate collision free 3-D trajectories. In this paper, we use forward-looking stereo vision with a large horizontal and vertical field of view and project range from stereo into a novel robot-centered, cylindrical, inverse range map we call an egocylinder. With this implementation we reduce the complexity of our world representation from a 3D map to a 2.5D image-space representation, which supports very efficient motion planning and collision checking, and allows to implement configuration space expansion as an image processing function directly on the egocylinder. Deploying a fast reactive motion planner directly on the configuration space expanded egocylinder image, we demonstrate the effectiveness of this new approach experimentally in an indoor environment.", "date": "2016-05-25", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "Art. No. 98361R", "id_number": "CaltechAUTHORS:20180719-104224891", "isbn": "9781510600775", "book_title": "Micro- and Nanotechnology Sensors, Systems, and Applications VIII", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180719-104224891", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Army Research Laboratory" }, { "agency": "NASA/JPL/Caltech" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "George-T", "name": { "family": "George", "given": "Thomas" } }, { "id": "Dutta-A-K", "name": { "family": "Dutta", "given": "Achyut K." } }, { "id": "Islam-M-S", "name": { "family": "Islam", "given": "M. Saif" } } ] }, "doi": "10.1117/12.2224695", "primary_object": { "basename": "98361R.pdf", "url": "https://authors.library.caltech.edu/records/hcndr-5e639/files/98361R.pdf" }, "pub_year": "2016", "author_list": "Brockers, R.; Fragoso, A.; et el." }, { "id": "https://authors.library.caltech.edu/records/0bbyd-tan16", "eprint_id": 73046, "eprint_status": "archive", "datestamp": "2023-08-20 11:31:24", "lastmod": "2023-10-24 14:59:32", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ramezani-Alireza", "name": { "family": "Ramezani", "given": "Alireza" }, "orcid": "0000-0002-3391-5288" }, { "id": "Shi-Xichen", "name": { "family": "Shi", "given": "Xichen" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Hutchinson-Seth", "name": { "family": "Hutchinson", "given": "Seth" }, "orcid": "0000-0002-3949-6061" } ] }, "title": "Bat Bot (B2), a biologically inspired flying machine", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2016 IEEE. \n\nThis research was supported by NSF Grant 1427111.", "abstract": "It is challenging to analyze the aerial locomotion of bats because of the complicated and intricate relationship between their morphology and flight capabilities. Developing a biologically inspired bat robot would yield insight into how bats control their body attitude and position through the complex interaction of nonlinear forces (e.g., aerodynamic) and their intricate musculoskeletal mechanism. The current work introduces a biologically inspired soft robot called Bat Bot (B2). The overall system is a flapping machine with 5 Degrees of Actuation (DoA). This work reports on some of the preliminary untethered flights of B2. B2 has a nontrivial morphology and it has been designed after examining several biological bats. Key DoAs, which contribute significantly to bat flight, are picked and incorporated in B2's flight mechanism design. These DoAs are: 1) forelimb flapping motion, 2) forelimb mediolateral motion (folding and unfolding) and 3) hindlimb dorsoventral motion (upward and downward movement).", "date": "2016-05", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "3219-3226", "id_number": "CaltechAUTHORS:20161221-074429456", "isbn": "978-1-4673-8026-3", "book_title": "2016 IEEE International Conference on Robotics and Automation (ICRA)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161221-074429456", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "CMMI-1427111" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/ICRA.2016.7487491", "pub_year": "2016", "author_list": "Ramezani, Alireza; Shi, Xichen; et el." }, { "id": "https://authors.library.caltech.edu/records/drywh-hc271", "eprint_id": 71932, "eprint_status": "archive", "datestamp": "2023-08-20 10:48:48", "lastmod": "2024-01-13 20:19:26", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "G\u00f3mez-F", "name": { "family": "G\u00f3mez", "given": "F." } }, { "id": "Blackburn-H-M", "name": { "family": "Blackburn", "given": "H. M." } }, { "id": "Rudman-M", "name": { "family": "Rudman", "given": "M." } }, { "id": "Sharma-A-S", "name": { "family": "Sharma", "given": "A. S." }, "orcid": "0000-0002-7170-1627" }, { "id": "McKeon-B-J", "name": { "family": "McKeon", "given": "B. J." }, "orcid": "0000-0003-4220-1583" } ] }, "title": "On the Coupling of Direct Numerical Simulation and Resolvent Analysis", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2016 Springer International Publishing. \n\nFirst Online: 03 March 2016. \n\nThe authors acknowledge financial support from the Australian Research Council through the ARC Discovery Project DP130103103, and from Australia's National Computational Infrastructure via Merit Allocation Scheme Grant D77.", "abstract": "The present contribution explores the relationship between response and forcing via amplification mechanisms in the Navier\u2013Stokes equations applied to a turbulent pipe flow. A novel numerical method coupling direct numerical simulation with the resolvent model [J. Fluid Mech. 658, 336-382 (2010)] is developed in order to reveal the exact distribution of the nonlinear forcing terms, originally unknown in the model. The obtained results highlight the major role of the nonlinear terms in the energy spectra.", "date": "2016-03-03", "date_type": "published", "publisher": "Springer", "place_of_pub": "Cham", "pagerange": "87-91", "id_number": "CaltechAUTHORS:20161111-092925356", "isbn": "978-3-319-29129-1", "book_title": "Progress in Turbulence VI", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161111-092925356", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Australian Research Council", "grant_number": "DP130103103" }, { "agency": "Australia National Computational Infrastructure", "grant_number": "D77" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Peinke-J", "name": { "family": "Peinke", "given": "Joachim" } }, { "id": "Kampers-G", "name": { "family": "Kampers", "given": "Gerrit" } }, { "id": "Oberlack-M", "name": { "family": "Oberlack", "given": "Martin" } }, { "id": "Wac\u0142awczyk-M", "name": { "family": "Wac\u0142awczyk", "given": "Marta" } }, { "id": "Talamelli-A", "name": { "family": "Talamelli", "given": "Alessandro" } } ] }, "doi": "10.1007/978-3-319-29130-7_16", "pub_year": "2016", "author_list": "G\u00f3mez, F.; Blackburn, H. M.; et el." }, { "id": "https://authors.library.caltech.edu/records/gpdny-rth26", "eprint_id": 73002, "eprint_status": "archive", "datestamp": "2023-08-20 09:53:02", "lastmod": "2023-10-24 14:56:52", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Gade-Shripad", "name": { "family": "Gade", "given": "Shripad" } }, { "id": "Paranjape-A-A", "name": { "family": "Paranjape", "given": "Aditya A." }, "orcid": "0000-0002-3164-3215" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Robotic Herding Using Wavefront Algorithm: Performance and Stability", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2015 AIAA American Institute of Aeronautics and Astronautics. \n\nThis work was supported by the National Science Foundation Career Award NSF IIS-1253758.", "abstract": "This paper is concerned with robotic herding of a swarm of birds by another adversarial agent, referred\nto as the pursuer. The objective of herding is to prevent the birds from entering a specified volume of space,\nsuch as the air space around an airport. The n-Wavefront algorithm was introduced by the authors in a\nprior paper to enable herding of a swarm of birds using a robotic unmanned aerial vehicle. In this paper,\nthe performance and stability characteristics are analyzed using tools from linear and nonlinear stability\ntheory, with the aim of proving its performance and identifying the permissible and optimum values of the\ncontrol parameters. It is shown that, using the n-Wavefront algorithm, a pursuer can successfully maneuver\nthe birds around the prescribed perimeter while ensuring that the swarm does not undergo fragmentation\nas a result of its response to the presence of the pursuer.", "date": "2016-01-08", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics (AIAA)", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2016-1378", "id_number": "CaltechAUTHORS:20161220-143603084", "isbn": "978-1-62410-389-6", "book_title": "AIAA Guidance, Navigation, and Control Conference, 2016", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161220-143603084", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "IIS-1253758" } ] }, "other_numbering_system": { "items": [ { "id": "2016-1378", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2016-1378", "pub_year": "2016", "author_list": "Gade, Shripad; Paranjape, Aditya A.; et el." }, { "id": "https://authors.library.caltech.edu/records/as0sg-f0d69", "eprint_id": 97955, "eprint_status": "archive", "datestamp": "2023-08-20 09:51:21", "lastmod": "2023-10-18 16:54:46", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Schmidt-B-E", "name": { "family": "Schmidt", "given": "B. E." }, "orcid": "0000-0001-9193-7760" }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "J. E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "Measurements of Instability in Supersonic Flow with Injection by Time-Resolved Flow Visualization", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2016 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 2 Jan 2016. \n\nThanks to Bahram Valiferdowsi, Ali Kiani, and Joe Haggerty for assistance with the models used in the present study. Additional thanks are due to Neal Bitter for insights into the transition process in supersonic flows. Bryan Schmidt acknowledges the support of Foster and Coco Stanback STEM Fellowship for his graduate studies.", "abstract": "Experiments were performed in a Mach 4 Ludwieg tube to examine the transition process in flow over a sharp cone with boundary layer injection. Full-field images with nitrogen, helium and RC-318 injection reveal that transition occurs earlier with higher injection rates and with lighter injected gas. High-speed imaging at 290 kHz allows the measurement of wavelength and convective velocity by auto- and cross-correlation, respectively, in the cases with nitrogen injection. The wavelength is found to be approximately 8 mm with a convective velocity of 515 m/s, resulting in a frequency range of 60-70 kHz. These properties of the instability waves are roughly constant over all injection rates tested even though the thickness of the injection layer varies by a factor of two.", "date": "2016-01-02", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2016-0599", "id_number": "CaltechAUTHORS:20190816-130553141", "isbn": "9781624103933", "book_title": "54th AIAA Aerospace Sciences Meeting", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190816-130553141", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Foster and Coco Stanback Postdoctoral Fellowship" } ] }, "other_numbering_system": { "items": [ { "id": "2016-0599", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2016-0599", "pub_year": "2016", "author_list": "Schmidt, B. E. and Shepherd, J. E." }, { "id": "https://authors.library.caltech.edu/records/0qbp0-8c669", "eprint_id": 98282, "eprint_status": "archive", "datestamp": "2023-08-20 09:51:27", "lastmod": "2023-10-18 17:13:02", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Knisely-A-M", "name": { "family": "Knisely", "given": "A. M." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "J. M." }, "orcid": "0000-0003-3129-5035" } ] }, "title": "Geometry and Test-Time Effects on Hypervelocity Shock-Boundary Layer Interaction", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2016 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 2 Jan 2016.", "abstract": "Experiments are carried out to address potential sources of discrepancies between experiments and simulations of shock-boundary layer interactions in hypervelocity flow: spanwise effects on shock interactions and flow separation, as well as flow field evolution and potential unsteadiness. A double-wedge and double-cone geometry are studied in two hypersonic impulse facilities, the HET and T5. The test conditions in the two facilities are selected to have the same nominal stagnation enthalpy but different unit Reynolds number. For the double-wedge model, the extent of the finite edge effects on shock structure and heat flux is assessed using chemiluminescence and surface measurements respectively. Heat flux in the separated region shows no variation within a nondimensional span of 0.05 away from the centerline. Over the respective test times of 250 \u00b5s in HET and 1 ms in T5, the normalized heat flux data obtained in the two facilities over the same model are in very good agreement. The invisicid establishment period for the double-cone is in agreement between the two facilities.", "date": "2016-01-02", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2016-1979", "id_number": "CaltechAUTHORS:20190828-081824663", "isbn": "978-1-62410-393-3", "book_title": "54th AIAA Aerospace Sciences Meeting", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190828-081824663", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2016-1979", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2016-1979", "pub_year": "2016", "author_list": "Knisely, A. M. and Austin, J. M." }, { "id": "https://authors.library.caltech.edu/records/bx7wm-dcm31", "eprint_id": 98289, "eprint_status": "archive", "datestamp": "2023-08-20 09:51:05", "lastmod": "2023-10-18 17:13:22", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Sakovsky-M", "name": { "family": "Sakovsky", "given": "M." }, "orcid": "0000-0002-3683-8505" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "S." }, "orcid": "0000-0001-9373-3278" }, { "id": "Mallikarachchi-H-M-Y-C", "name": { "family": "Mallikarachchi", "given": "H. M. Y. C." } } ] }, "title": "Folding and Deployment of Closed Cross-Section Dual-Matrix Composite Booms", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2016 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 1 Jan 2016. \n\nThis research was supported by the AFOSR (award no. FA9550-13-1-0061, program manager Dr David Stargel).\n\nAccepted Version - sakovsky_et_al_2016.pdf
", "abstract": "A dual-matrix composite boom is proposed as a way of realizing a deployable closed cross-section boom that is stiff, lightweight, and can be packaged in small volumes. Little work exists studying the folding and deployment behavior of closed cross-section boom made of composite shells and this paper addresses this by investigating the behavior for two closed cross-section designs. Experimental techniques for measuring the folded shape of curved shells undergoing large deformations is presented. Furthermore, experimental measurements of the moment-rotation response of the two booms are discussed. A study using commercially available finite element software yields simulation techniques for successfully\npredicting the folded shape of closed-cross section booms. The drawbacks of the software when predicting the moment-rotation response are addressed. The application of these techniques for the chosen designs demonstrate that dual-matrix booms are a promising alternative to existing composite deployable booms.", "date": "2016-01-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2016-0970", "id_number": "CaltechAUTHORS:20190828-095135682", "isbn": "978-1-62410-394-0", "book_title": "3rd AIAA Spacecraft Structures Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190828-095135682", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-13-1-0061" } ] }, "other_numbering_system": { "items": [ { "id": "2016-0970", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Space-Solar-Power-Project" } ] }, "doi": "10.2514/6.2016-0970", "primary_object": { "basename": "sakovsky_et_al_2016.pdf", "url": "https://authors.library.caltech.edu/records/bx7wm-dcm31/files/sakovsky_et_al_2016.pdf" }, "pub_year": "2016", "author_list": "Sakovsky, M.; Pellegrino, S.; et el." }, { "id": "https://authors.library.caltech.edu/records/hxt2e-nmv51", "eprint_id": 98285, "eprint_status": "archive", "datestamp": "2023-08-20 09:51:00", "lastmod": "2023-10-18 17:13:12", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bradford-S-C", "name": { "family": "Bradford", "given": "Samuel Case" } }, { "id": "Hofmann-D-C", "name": { "family": "Hofmann", "given": "Douglas C." } }, { "id": "Roberts-S-N", "name": { "family": "Roberts", "given": "Scott N." } }, { "id": "Steeves-J-B", "name": { "family": "Steeves", "given": "John B." } }, { "id": "Wojnar-C-S", "name": { "family": "Wojnar", "given": "Charles S." } }, { "id": "Kochmann-D-M", "name": { "family": "Kochmann", "given": "Dennis M." }, "orcid": "0000-0002-9112-6615" } ] }, "title": "Energy-Efficient Active Reflectors with Improved Mechanical Stability and Improved Thermal Performance", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2016 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 1 Jan 2016.", "abstract": "Controlling surface wavefront of apertures using a distributed array of actuators to mechanically correct the surface has been widely studied. Traditional active reflector systems require a sustained voltage profile which holds each actuator at a specific strain state to control the surface of the reflector. Each actuator, typically piezoelectric, draws a small amount of power under nominal operation. This power draw is small, but can complicate mission designs that depend on a cryogenic primary reflector surface. In this study we have extended the results of our previous work to include nonlinear piezoelectric actuation for active reflector systems. By deliberately operating in the nonlinear regime, it is possible to deform the actuators in such a way that the reflector surface maintains its corrected shape without sustained power. Demonstration of unpowered primary mirror wavefront control has positioned the technology as suitable for cryogenic/infrared systems. This report describes a nonlinear piezoelectric characterization campaign, and the associated nonlinear energy-efficient active reflector demonstration.", "date": "2016-01-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2016-0702", "id_number": "CaltechAUTHORS:20190828-084449277", "isbn": "978-1-62410-394-0", "book_title": "3rd AIAA Spacecraft Structures Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190828-084449277", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2016-0702", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2016-0702", "pub_year": "2016", "author_list": "Bradford, Samuel Case; Hofmann, Douglas C.; et el." }, { "id": "https://authors.library.caltech.edu/records/2jd2y-8mc90", "eprint_id": 72982, "eprint_status": "archive", "datestamp": "2023-08-20 09:48:08", "lastmod": "2023-10-24 14:55:26", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chilan-Christian-M", "name": { "family": "Chilan", "given": "Christian M." } }, { "id": "Herber-Daniel-R", "name": { "family": "Herber", "given": "Daniel R." } }, { "id": "Nakka-Yashwanth-K", "name": { "family": "Nakka", "given": "Yashwanth K." }, "orcid": "0000-0001-7897-3644" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Allison-James-T", "name": { "family": "Allison", "given": "James T." } }, { "id": "Aldrich-Jack-B", "name": { "family": "Aldrich", "given": "Jack B." } }, { "id": "Alvarez-Salazar-O-S", "name": { "family": "Alvarez-Salazar", "given": "Oscar S." } } ] }, "title": "Co-Design of Strain-Actuated Solar Arrays for Precision Pointing and Jitter Reduction", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2016 American Institute of Aeronautics and Astronautics. \n\nGovernment sponsorship is acknowledged. The research was in part carried out at the Jet Propulsion Laboratory, California Institute of Technology under a contract with the National Aeronautics and Space Administration. The authors acknowledge help from Giri Subramanian and Kevin Lohan during the initial phases of the project.", "abstract": "Many important spacecraft operations require precision pointing such as space astronomy and high-rate communications. Traditionally, reaction wheels have been used for this purpose but they have been considered unreliable for many missions. This work presents the use strain-actuated solar arrays (SASA) for precision pointing and jitter reduction. Piezoelectric actuators can achieve higher precision and bandwidth than reaction wheels, and they can also provide quiet operation for sensitive instruments. The representation of the array dynamics in the studies presented here is based on Euler-Bernoulli beam theory for high-fidelity simulations. This work also presents a methodology for the combined design of distributed structural geometry for the arrays and distributed control system design. The array geometry design allows for a distributed thickness profile, and the control design determines the distributed moment on the array. Fundamental limits on slew magnitude are found using pseudo-rigid body dynamic model (PRBDM) theory. A parametric study based on a representative spacecraft model demonstrates the validity of the proposed approach and illustrates optimal design trends.", "date": "2016-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics (AIAA)", "place_of_pub": "Reston, VA", "pagerange": "Art. No.-2016", "id_number": "CaltechAUTHORS:20161220-115042791", "isbn": "978-1-62410-392-6", "book_title": "Structures, Structural Dynamics, and Materials Conference 57th AIAA/ASCE/AHS/ASC", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161220-115042791", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" } ] }, "other_numbering_system": { "items": [ { "id": "2016-0162", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/MSDM16", "pub_year": "2016", "author_list": "Chilan, Christian M.; Herber, Daniel R.; et el." }, { "id": "https://authors.library.caltech.edu/records/5zrfw-nhx55", "eprint_id": 70701, "eprint_status": "archive", "datestamp": "2023-08-20 09:46:57", "lastmod": "2023-10-20 23:21:21", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hogstrom-K", "name": { "family": "Hogstrom", "given": "Kristina" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Methods for Characterizing the Reliability of Deployable Modules for Large Optical Reflectors", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2016 AIAA. \n\nThis work was supported by the NASA Space Technology Research Fellowship #NNX13AL67H, with the help and mentorship of Erik Komendera, John Dorsey, and Bill Doggett at NASA Langley Research Center and Stuart Shaklan at the Jet Propulsion Laboratory. Many thanks to Isabelle Phinney for her help with setting up experiments.\n\nSubmitted - Scitech_paper.pdf
", "abstract": "The In-Space Telescope Assembly Robotics (ISTAR) project has proposed an architecture for a large robotically-assembled telescope in space, comprised of many deployable truss modules. The truss modules are based on the Pactruss deployment scheme and are equipped with Rolamite tape spring hinges. Fabrication and assembly errors that arise from bulk manufacturing the modules may make the deployment unreliable. A simulation toolkit has been developed to characterize the deployment behavior of the module in the presence of such errors. This paper first outlines the details of the toolkit, including the truss model, the Rolamite hinge model, and the simulation methodology. It then describes the experiment designed to validate the toolkit. A module was constructed and deployed while tracking the displacements of a select node and the rotations of the Rolamite hinges. The measured shape of this module was recreated in the simulation model and the same parameters were obtained. It was found that the experimental and simulated nodal displacements matched within 10%. The experimental hinge behavior was generally captured in the simulation, with some discrepancies in the latching of one hinge. The possible causes for the discrepancies and ongoing work to improve the results are discussed in the paper.", "date": "2016-01", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2016-2164", "id_number": "CaltechAUTHORS:20160930-132028713", "isbn": "978-1-62410-394-0", "book_title": "3rd AIAA Spacecraft Structures Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160930-132028713", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA Space Technology Research Fellowship", "grant_number": "NNX13AL67H" } ] }, "other_numbering_system": { "items": [ { "id": "AIAA 2016-2164", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2016-2164", "primary_object": { "basename": "Scitech_paper.pdf", "url": "https://authors.library.caltech.edu/records/5zrfw-nhx55/files/Scitech_paper.pdf" }, "pub_year": "2016", "author_list": "Hogstrom, Kristina and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/j5bad-hx679", "eprint_id": 70700, "eprint_status": "archive", "datestamp": "2023-08-20 09:46:53", "lastmod": "2023-10-20 23:21:17", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Delapierre-M", "name": { "family": "Delapierre", "given": "M." } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "S." }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Membrane Spin Up in a Normal Gravity Field: Experiments and Simulations", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2016 AIAA. \n\nWe thank Professor Sigrid Leyendecker and Tristan Schlogl for helpful discussions and advice. Financial support from the Northrop Grumman Corporation is gratefully acknowledged.\n\nSubmitted - Membrane_spinup_SciTech2016_NEW.pdf
", "abstract": "Finite element simulations and experimental observations of the spin up in vacuum of a thin membrane loaded by gravity are presented. The numerical techniques take into account the run time of each simulation and energy convergence; it is shown that accurate results can be obtained quite quickly in a rotating reference frame, and that including stiffness-proportional material damping helps convergence of the integration. It is also found that a very fine finite element mesh around the hub of the membrane is required to obtain consistent results. The experimental setup allows spinning of the membrane in a vacuum box; a measurement technique that uses stereo Digital Image Correlation is presented. A comparison between experiments and simulations using characteristic parameters of the shape of a membrane, i.e. the number of rotational symmetric waves, the average deflection, and the elastic bending strain energy of the membrane, shows good agreement between experiments and simulations.", "date": "2016-01", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2016-1216", "id_number": "CaltechAUTHORS:20160930-131912958", "isbn": "978-1-62410-394-0", "book_title": "3rd AIAA Spacecraft Structures Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160930-131912958", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Northrop Grumman Corporation" } ] }, "other_numbering_system": { "items": [ { "id": "2016-1216", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Space-Solar-Power-Project" } ] }, "doi": "10.2514/6.2016-1216", "primary_object": { "basename": "Membrane_spinup_SciTech2016_NEW.pdf", "url": "https://authors.library.caltech.edu/records/j5bad-hx679/files/Membrane_spinup_SciTech2016_NEW.pdf" }, "pub_year": "2016", "author_list": "Delapierre, M. and Pellegrino, S." }, { "id": "https://authors.library.caltech.edu/records/5b04a-92x39", "eprint_id": 70244, "eprint_status": "archive", "datestamp": "2023-08-20 09:46:38", "lastmod": "2023-10-20 21:59:13", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Gupta-A", "name": { "family": "Gupta", "given": "Arjun" } }, { "id": "Costantine-J", "name": { "family": "Costantine", "given": "J." } }, { "id": "Tawk-Y", "name": { "family": "Tawk", "given": "Y." } }, { "id": "Christodoulou-C-G", "name": { "family": "Christodoulou", "given": "Christos G." } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "S." }, "orcid": "0000-0001-9373-3278" }, { "id": "Sakovsky-M", "name": { "family": "Sakovsky", "given": "M." }, "orcid": "0000-0002-3683-8505" } ] }, "title": "A Deployable Vivaldi-fed Conical Horn Antenna for CubeSats", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2016 IEEE. \n\nDate Added to IEEE Xplore: 21 March 2016.", "abstract": "The advent of CubeSats has revolutionized the space research industry. The small physical size and constraints owing to outer space applications present significant challenges for antenna engineers to come up with innovative solutions. This paper presents a novel wide band antenna high gain antenna which is capable of deploying from a CubeSat platform.", "date": "2016-01", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "1-2", "id_number": "CaltechAUTHORS:20160909-112312357", "isbn": "978-1-4673-8678-4", "book_title": "2016 United States National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160909-112312357", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/USNC-URSI-NRSM.2016.7436244", "pub_year": "2016", "author_list": "Gupta, Arjun; Costantine, J.; et el." }, { "id": "https://authors.library.caltech.edu/records/k6xmf-g5p42", "eprint_id": 70699, "eprint_status": "archive", "datestamp": "2023-08-20 09:46:49", "lastmod": "2023-10-20 23:21:14", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Arya-M", "name": { "family": "Arya", "given": "Manan" } }, { "id": "Lee-Nicolas", "name": { "family": "Lee", "given": "Nicolas" }, "orcid": "0000-0001-5500-1324" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Ultralight Structures for Space Solar Power Satellites", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2016 AIAA. \n\nFinancial support from Northrop Grumman Corporation is gratefully acknowledged. The research presented in this paper was carried out in collaboration with Professors Harry Atwater and Ali Hajimiri and their research groups. Drs. Dennis Callahan and Florian Bohn helped with the design and the construction of the tile mockup.\n\nSubmitted - 2016_sdm_as_submitted.pdf
", "abstract": "The design of a deployable spacecraft, measuring 60 m \u00d7 60 m, and with an areal density 100 g m^(\u22122) , is described. This spacecraft can be packaged into a cylinder measuring 1.5 m in height and 1 m in diameter. It can be deployed to a flat configuration, where it acts as a stiff, lightweight support framework for multifunctional tiles that collect sunlight, generate electric power, and transmit to a ground station on Earth.", "date": "2016-01", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2016-1950", "id_number": "CaltechAUTHORS:20160930-131726070", "isbn": "978-1-62410-394-0", "book_title": "3rd AIAA Spacecraft Structures Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160930-131726070", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Keck Institute for Space Studies (KISS)" }, { "agency": "Northrop Grumman Corporation" } ] }, "other_numbering_system": { "items": [ { "id": "2016-1950", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "Keck-Institute-for-Space-Studies" }, { "id": "GALCIT" }, { "id": "Space-Solar-Power-Project" } ] }, "doi": "10.2514/6.2016-1950", "primary_object": { "basename": "2016_sdm_as_submitted.pdf", "url": "https://authors.library.caltech.edu/records/k6xmf-g5p42/files/2016_sdm_as_submitted.pdf" }, "pub_year": "2016", "author_list": "Arya, Manan; Lee, Nicolas; et el." }, { "id": "https://authors.library.caltech.edu/records/knwvh-d7f12", "eprint_id": 72427, "eprint_status": "archive", "datestamp": "2023-08-20 09:48:01", "lastmod": "2023-10-23 22:33:30", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ramezani-Alireza", "name": { "family": "Ramezani", "given": "Alireza" }, "orcid": "0000-0002-3391-5288" }, { "id": "Shi-Xichen", "name": { "family": "Shi", "given": "Xichen" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Hutchinson-Seth", "name": { "family": "Hutchinson", "given": "Seth" }, "orcid": "0000-0002-3949-6061" } ] }, "title": "Modeling and Nonlinear Flight Controller Synthesis of a Bat-Inspired Micro Aerial Vehicle", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2015 American Institute of Aeronautics and Astronautics.", "abstract": "This work examines the control of nonlinear dynamic systems to synthesize a flight controller for Bat Bot (B2). B2 is a bat-inspired Micro Aerial Vehicle (MAV) which has\narticulated arm wings with several actuated and passive joints. B2 is designed to mimic the flight apparatus of actual biological bats, which is distinguished from other animals such as birds because bats employ numerous joints\u2013more than 20 joint angles per each wing\u2013and exhibit sophisticated motion patterns. B2 has significantly fewer degrees of freedom (DoF) than biological bats and the existing movements in the mechanism of B2 are: flapping\nmotion of the wings, folding and unfolding of the wings and dorsoventral movements of the legs. The current work contributes to recent attempts to produce autonomous flapping flight motions in a bio-inspired robot with nontrivial morphology. This work uses the Lagrange framework to develop a nonlinear dynamic model for B2, and it proposes a nonlinear controller based on the theory of singular perturbation in order to track desired attitude angles.", "date": "2016-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics (AIAA)", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2016-1376", "id_number": "CaltechAUTHORS:20161130-080521015", "isbn": "978-1-62410-389-6", "book_title": "AIAA Guidance, Navigation, and Control Conference 2016", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161130-080521015", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2016-1376", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2016-1376", "pub_year": "2016", "author_list": "Ramezani, Alireza; Shi, Xichen; et el." }, { "id": "https://authors.library.caltech.edu/records/935y3-taq38", "eprint_id": 64986, "eprint_status": "archive", "datestamp": "2023-08-20 09:34:28", "lastmod": "2023-10-17 22:02:19", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Karanjgaokar-N", "name": { "family": "Karanjgaokar", "given": "Nikhil" } }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "Guruswami" }, "orcid": "0000-0002-2912-0001" } ] }, "title": "Study of Energy Contributions in Granular Materials During Impact", "ispublished": "unpub", "full_text_status": "public", "keywords": "Digital image correlation \u2013 Granular materials \u2013 Granular element method \u2013 Force chains", "note": "\u00a9 2016 The Society for Experimental Mechanics, Inc.", "abstract": "A drop-tower experimental setup was developed for the impact testing of 2D assembly of cylinders and 3D assembly of spheres with impactor velocity of around 6 m/s. This drop tower setup was used to load 2D granular assembly of polyurethane cylinders of 1\u2033\u20131.25\u2033 length with three different diameters of 1/4\u2033, 3/8\u2033 and 1/2\u2033. A high speed camera was used for recording the images at speeds between 10,000 and 50,000 fps to monitor the deformation of the cylinders. The inter-particle forces in these experiments were calculated using a GEM based force inference technique. The resultant force networks in the granular assemblies were then qualitatively compared to the acceleration fields and strain fields observed during the experiments at different time instants. The conservation of energy was used to plot the evolution of energy components like kinetic energy, strain energy, friction and dissipative components during impact experiments.", "date": "2016", "date_type": "published", "publisher": "Springer", "place_of_pub": "Cham", "pagerange": "199-204", "id_number": "CaltechAUTHORS:20160303-085005371", "isbn": "978-3-319-22451-0", "book_title": "Dynamic Behavior of Materials", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160303-085005371", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Song-Bo", "name": { "family": "Song", "given": "Bo" } }, { "id": "Lamberson-L", "name": { "family": "Lamberson", "given": "Leslie" } }, { "id": "Casem-D", "name": { "family": "Casem", "given": "Daniel" } }, { "id": "Kimberley-J", "name": { "family": "Kimberley", "given": "Jamie" } } ] }, "doi": "10.1007/978-3-319-22452-7_28", "pub_year": "2016", "author_list": "Karanjgaokar, Nikhil and Ravichandran, Guruswami" }, { "id": "https://authors.library.caltech.edu/records/zp66a-0kb76", "eprint_id": 70675, "eprint_status": "archive", "datestamp": "2023-08-22 17:06:32", "lastmod": "2023-10-20 23:19:27", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Leonard-A", "name": { "family": "Leonard", "given": "A." } } ] }, "title": "Large-Eddy Simulation of the Navier-Stokes Equations: Deconvolution, Particle Methods, and Super-Resolution", "ispublished": "unpub", "full_text_status": "public", "keywords": "large-eddy simulation; deconvolution; Lagrangian particle methods; super-resolution", "note": "\u00a9 2016 World Scientific Publishing Co Pte Ltd.", "abstract": "The technique of large-eddy simulation (LES) continues to play an important role in the numerical simulation of fluid dynamic processes in engineering and scientific applications. This paper will review and discuss a few of the various schemes for LES applied to the incompressible Navier-Stokes equations and to the scalar advection-diffusion equation. In particular, subgrid models based on deconvolution will be discussed. An interesting connection between the tensor diffusivity model, a particular version of a deconvolution model, and Lagrangian particle methods for the vorticity transport equation and for the scalar convection-diffusion equation will be explored. In addition, the possibility of using super-resolution, i.e. recovering fine-scale information knowing only coarse-scale information, in LES will be investigated.", "date": "2016", "date_type": "published", "publisher": "World Scientific", "place_of_pub": "Singapore", "pagerange": "1-16", "id_number": "CaltechAUTHORS:20160930-083031310", "isbn": "978-981-4635-16-5", "book_title": "Advances in Computation, Modeling and Control of Transitional and Turbulent Flows", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160930-083031310", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Sengupta-T-K", "name": { "family": "Sengupta", "given": "Tapan Kumar" } } ] }, "doi": "10.1142/9789814635165_0001", "pub_year": "2016", "author_list": "Leonard, A." }, { "id": "https://authors.library.caltech.edu/records/p1yq5-1fh78", "eprint_id": 64415, "eprint_status": "archive", "datestamp": "2023-08-22 17:05:50", "lastmod": "2024-01-13 16:40:37", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hsueh-Chun-Jen", "name": { "family": "Hsueh", "given": "Chun-Jen" } }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "Guruswami" }, "orcid": "0000-0002-2912-0001" }, { "id": "Bhattacharya-K", "name": { "family": "Bhattacharya", "given": "Kaushik" }, "orcid": "0000-0003-2908-5469" } ] }, "title": "Measuring the Effective Fracture Toughness of Heterogeneous Materials", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Fracture toughness; Heterogeneous material; Surfing boundary conditions; Digital image correlation; Brittle material", "note": "\u00a9 2016 The Society for Experimental Mechanics, Inc. \n\nWe gratefully acknowledge the financial support of the U.S. National Science Foundation (Grant No. CMMI-1201102).", "abstract": "Heterogeneous materials where the scale of the heterogeneities is small compared to the scale of applications are common in nature. These materials are also engineered synthetically with the aim of improving performance. The overall properties of heterogeneous materials can be different from those of its constituents; however, it is challenging to characterize effective fracture toughness of these materials. We present a new method of experimentally determining the effective fracture toughness. The key idea is to impose a steady process at the macroscale while allowing the fracture process to freely explore at the level of microstructure. We apply a time-dependent displacement boundary condition called the surfing boundary condition that corresponds to a steadily propagating macroscopic crack opening displacement. We then measure the full-field displacement using digital image correlation (DIC) method, and use it to obtain the macroscopic energy release rate. In particular, we develop a global approach to extract information from DIC. The effective toughness is obtained at the peak of the energy release rate. Finally, the full field images also provide us insight into the role of the microstructure in determining effective toughness.", "date": "2016", "date_type": "published", "publisher": "Springer", "place_of_pub": "Cham", "pagerange": "151-155", "id_number": "CaltechAUTHORS:20160211-094810104", "isbn": "978-3-319-21610-2", "book_title": "Fracture, Fatigue, Failure and Damage Evolution", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160211-094810104", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "CMMI-1201102" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Beese-A-M", "name": { "family": "Beese", "given": "Allison M." } }, { "id": "Zehnder-A-T", "name": { "family": "Zehnder", "given": "Alan T." } }, { "id": "Xia-Shuman", "name": { "family": "Xia", "given": "Shuman" } } ] }, "doi": "10.1007/978-3-319-21611-9_19", "pub_year": "2016", "author_list": "Hsueh, Chun-Jen; Ravichandran, Guruswami; et el." }, { "id": "https://authors.library.caltech.edu/records/9c8hf-m7j61", "eprint_id": 73161, "eprint_status": "archive", "datestamp": "2023-08-20 09:21:23", "lastmod": "2023-10-24 15:05:16", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Paranjape-A-A", "name": { "family": "Paranjape", "given": "Aditya A." }, "orcid": "0000-0002-3164-3215" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Output feedback stabilization of linear PDEs with finite dimensional input-output maps and Kelvin-Voigt damping", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2015 IEEE. \n\nDate Added to IEEE Xplore: 11 February 2016. \n\nThe authors gratefully acknowledge the reviewers' comments and suggestions. The second author gratefully acknowledges support by the National Science Foundation (IIS-1253758; CMMI-1427111)\n\nSubmitted - PDEinputouputCDC2015.pdf
", "abstract": "In this paper, we consider systems of partial differential equations with a finite relative degree between the input and the output. In such systems, an output feedback controller can be constructed to regulate the output with the desired convergence properties. Although the zero dynamics are infinite dimensional, we show that the controller alters the boundary conditions in such a way that it leads to a predictable expansion in the stable operating envelope of the system. Moreover, the expansion of the stable envelope depends only on the boundary conditions and the structure of the PDE, and is independent of the system parameters. The methodology is extended to output tracking and time-varying forcing functions as well. The phenomenon investigated in the paper is quite unique to partial differential equations and without any parallel in systems of ODEs.", "date": "2015-12", "date_type": "published", "publisher": "IEEE", "place_of_pub": "New York, NY", "pagerange": "578-583", "id_number": "CaltechAUTHORS:20161222-124053440", "isbn": "978-1-4799-7886-1", "book_title": "54th IEEE Conference on Decision and Control (CDC)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161222-124053440", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "IIS-1253758" }, { "agency": "NSF", "grant_number": "CMMI-1427111" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/CDC.2015.7402291", "primary_object": { "basename": "PDEinputouputCDC2015.pdf", "url": "https://authors.library.caltech.edu/records/9c8hf-m7j61/files/PDEinputouputCDC2015.pdf" }, "pub_year": "2015", "author_list": "Paranjape, Aditya A. and Chung, Soon-Jo" }, { "id": "https://authors.library.caltech.edu/records/txx6y-12678", "eprint_id": 87980, "eprint_status": "archive", "datestamp": "2023-08-20 08:16:24", "lastmod": "2024-01-14 20:28:11", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Polidan-R-S", "name": { "family": "Polidan", "given": "Ronald S." } }, { "id": "Breckinridge-J-B", "name": { "family": "Breckinridge", "given": "James B." }, "orcid": "0000-0002-9488-098X" }, { "id": "Lillie-C-F", "name": { "family": "Lillie", "given": "Charles F." } }, { "id": "MacEwen-H-A", "name": { "family": "MacEwen", "given": "Howard A." } }, { "id": "Flannery-M-R", "name": { "family": "Flannery", "given": "Martin R." } }, { "id": "Dailey-D-R", "name": { "family": "Dailey", "given": "Dean R." } }, { "id": "Baldauf-B", "name": { "family": "Baldauf", "given": "Brian" } }, { "id": "Makowski-D", "name": { "family": "Makowski", "given": "David" } }, { "id": "Rafanelli-G-L", "name": { "family": "Rafanelli", "given": "Gerard L." } } ] }, "title": "An evolvable space telescope for future astronomical missions 2015 update", "ispublished": "unpub", "full_text_status": "public", "keywords": "Space telescopes, alternate architectures, segmented telescopes, in-space assembly and servicing, synthetic apertures", "note": "\u00a9 2015 Society of Photo-Optical Instrumentation Engineers (SPIE). \n\nThe authors would like to acknowledge strong support and internal funding from Northrop Grumman Aerospace Systems and very helpful comments, suggestions, and criticisms from a variety of people, including Jonathan Arenberg, Suzanne Casement, Alberto Conti, Michael Triller, Amber Bauermeister, Mark Folkman, Keith Leavitt, Mitchell Haeri, Neil Malone, Susan B. Spencer, Douglas W. Wolfe, Marc Postman, Ken Sembach, Wes Traub, and Harley Thronson.\n\nPublished - 960207.pdf
", "abstract": "In 2014 we presented a concept for an Evolvable Space Telescope (EST) that was assembled on orbit in 3 stages, growing from a 4x12 meter telescope in Stage 1, to a 12-meter filled aperture in Stage 2, and then to a 20-meter filled aperture in Stage 3. Stage 1 is launched as a fully functional telescope and begins gathering science data immediately after checkout on orbit. This observatory is then periodically augmented in space with additional mirror segments, structures, and newer instruments to evolve the telescope over the years to a 20-meter space telescope. In this 2015 update of EST we focus upon three items: 1) a restructured Stage 1 EST with three mirror segments forming an off-axis telescope (half a 12-meter filled aperture); 2) more details on the value and architecture of the prime focus instrument accommodation; and 3) a more in depth discussion of the essential in-space infrastructure, early ground testing and a concept for an International Space Station testbed called MoDEST. In addition to the EST discussions we introduce a different alternative telescope architecture: a Rotating Synthetic Aperture (RSA). This is a rectangular primary mirror that can be rotated to fill the UV-plane. The original concept was developed by Raytheon Space and Airborne Systems for non-astronomical applications. In collaboration with Raytheon we have begun to explore the RSA approach as an astronomical space telescope and have initiated studies of science and cost performance.", "date": "2015-09-22", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "Art. No. 960207", "id_number": "CaltechAUTHORS:20180718-155617229", "isbn": "9781628417685", "book_title": "UV/Optical/IR Space Telescopes and Instruments: Innovative Technologies and Concepts VII", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180718-155617229", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Northrop Grumman Corporation" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "MacEwen-H-A", "name": { "family": "MacEwen", "given": "Howard A." } }, { "id": "Breckinridge-J-B", "name": { "family": "Breckinridge", "given": "James B." } } ] }, "doi": "10.1117/12.2189105", "primary_object": { "basename": "960207.pdf", "url": "https://authors.library.caltech.edu/records/txx6y-12678/files/960207.pdf" }, "pub_year": "2015", "author_list": "Polidan, Ronald S.; Breckinridge, James B.; et el." }, { "id": "https://authors.library.caltech.edu/records/9awsf-w3a26", "eprint_id": 73057, "eprint_status": "archive", "datestamp": "2023-08-20 07:47:55", "lastmod": "2023-10-24 15:00:12", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Kong-Edmund", "name": { "family": "Kong", "given": "Edmund" } }, { "id": "Miller-D-W", "name": { "family": "Miller", "given": "David" }, "orcid": "0000-0001-6099-0614" } ] }, "title": "Dynamics and Control of Tethered Formation Flight Spacecraft Using the SPHERES Testbed", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2015 American Institute of Aeronautics and Astronautics. \n\nThe authors would like to gratefully acknowledge NASA for both financial and technical support for the MIT-SSL and PSI SPHERES Tether program. This work has been sponsored under NASA Phase II SBIR contract (Contract No.: NNG05CA09C). The authors would like to gratefully appreciate the technical support from the MIT SPHERES team including Steve Sell, Alvar Otero, Mark Hilstad, Simon Nolet, and Danielle Adams.\n\nPublished - gnc2005tether.pdf
", "abstract": "This paper elaborates on the theory and experiment of controlling tethered spacecraft formation without depending on thrusters. In dealing with such underactuated systems,\nmuch emphasis is placed on complete decentralization of the control and estimation algorithms in order to reduce the dimensionality and complication. The nonlinear equations\nof motions of multi-vehicle tethered spacecraft are derived by Lagrange's equations. Decentralization is then realized by the diagonalization technique and its stability is proven\nby contraction theory. The preliminary analysis predicts unstable dynamics depending on the direction of the tether motor. The controllability analysis indicates that both array resizing and spin-up are fully controllable only by the reaction wheels and the tether motor, thereby eliminating the need for thrusters. Based upon this analysis, gain-scheduling LQR controllers and nonlinear controllers by feedback linearization have been successfully implemented into the tethered SPHERES testbed, and tested at the NASA MSFCs flat floor facility using two and three SPHERES configurations. The relative sensing mechanism employing the ultrasound ranging system and the inertial gyro is also described.", "date": "2015-08-18", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics (AIAA)", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2005-6089", "id_number": "CaltechAUTHORS:20161221-090449955", "isbn": "978-1-62410-056-7", "book_title": "AIAA Guidance, Navigation, and Control Conference and Exhibit, 2005", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161221-090449955", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA", "grant_number": "NNG05CA09C" } ] }, "other_numbering_system": { "items": [ { "id": "2005-6089", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2005-6089", "primary_object": { "basename": "gnc2005tether.pdf", "url": "https://authors.library.caltech.edu/records/9awsf-w3a26/files/gnc2005tether.pdf" }, "pub_year": "2015", "author_list": "Chung, Soon-Jo; Kong, Edmund; et el." }, { "id": "https://authors.library.caltech.edu/records/35755-ed870", "eprint_id": 65842, "eprint_status": "archive", "datestamp": "2023-08-22 15:51:25", "lastmod": "2024-01-13 16:47:01", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Costantine-J", "name": { "family": "Costantine", "given": "J." } }, { "id": "Tawk-Y", "name": { "family": "Tawk", "given": "Y." } }, { "id": "Christodoulou-C-G", "name": { "family": "Christodoulou", "given": "C. G." } }, { "id": "Maqueda-I", "name": { "family": "Maqueda", "given": "I." } }, { "id": "Sakovsky-M", "name": { "family": "Sakovsky", "given": "M." }, "orcid": "0000-0002-3683-8505" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "S." }, "orcid": "0000-0001-9373-3278" } ] }, "title": "A New UHF Deployable Antenna for CubeSats", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "UHF antennas; antenna radiation patterns; satellite antennas; spiral antennas.", "note": "\u00a9 2015 IEEE.", "abstract": "This paper discusses the design of a new conical log spiral antenna that can operate at UHF frequencies. The antenna constitutes a suitable candidate for deployment on top of a 6U CubeSat system. The conical log spiral is designed to operate between 300 MHz and 600 MHz and exhibit circular polarization as well as an acceptable gain. The antenna is also required to satisfy size constraints by being compactly folded during launch and deployed successfully once in orbit.", "date": "2015-07", "date_type": "published", "publisher": "IEEE", "place_of_pub": "New York, NY", "pagerange": "1426-1427", "id_number": "CaltechAUTHORS:20160401-100827980", "isbn": "978-1-4799-7815-1", "book_title": "2015 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160401-100827980", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/APS.2015.7305102", "pub_year": "2015", "author_list": "Costantine, J.; Tawk, Y.; et el." }, { "id": "https://authors.library.caltech.edu/records/wq5bs-j1795", "eprint_id": 98315, "eprint_status": "archive", "datestamp": "2023-08-20 06:57:52", "lastmod": "2023-10-18 17:15:01", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Dunne-R", "name": { "family": "Dunne", "given": "R." } }, { "id": "McKeon-B-J", "name": { "family": "McKeon", "given": "B. J." }, "orcid": "0000-0003-4220-1583" } ] }, "title": "A study of separation on airfoils undergoing pitch, surge and combined motions", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2015 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 19 Jun 2015.", "abstract": "Vertical axis wind turbine blades undergo a large angle of attack and velocity variation during every turbine rotation. The flow over a NACA 0018 airfoil undergoing sinusoidal pitch, surge and combined motions at similar frequency, amplitude and Reynolds number as a commercial turbine was measured to investigate the effect of the different motions on the flow field. Two-dimensional, time resolved velocity fields were acquired using particle image velocimetry. Vorticity contours of the phase-averaged flow were used to visualize the separation process and shear layer development. The pitch-only ease is seen to separate earlier and at a lower angle of attack than the combined case. Results for surging airfoils at two angles of attack are presented, one fully separated, and one partially separated. Surge forward is shown to move the separation point toward the leading edge, while surge back moved it aft. The dynamics of the leading edge vortex in the combined pitch/surge and pitch motions are discussed.", "date": "2015-06-19", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2015-2882", "id_number": "CaltechAUTHORS:20190828-110109774", "isbn": "978-1-62410-363-6", "book_title": "33rd AIAA Applied Aerodynamics Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190828-110109774", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2015-2882", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2015-2882", "pub_year": "2015", "author_list": "Dunne, R. and McKeon, B. J." }, { "id": "https://authors.library.caltech.edu/records/pg8w9-8rk75", "eprint_id": 98312, "eprint_status": "archive", "datestamp": "2023-08-20 06:57:49", "lastmod": "2023-10-18 17:14:34", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Schmidt-B-E", "name": { "family": "Schmidt", "given": "B. E." }, "orcid": "0000-0001-9193-7760" }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "J. E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "Analysis of Focused Laser Differential Interferometry", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2015 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 19 Jun 2015.", "abstract": "A computational method for predicting the output of a focused laser differential inter-ferometer (FLDI) given all arbitrary density field is presented. The method is validated against analytical predictions and experimental data. The FLDI simulation software is applied to the problem of measuring Mack-mode wave packets in a hypervelocity boundary layer on a 5\u00b0 half-angle cone. The software is shown to compliment experiments by providing the necessary information to allow quantitative density fluctuation magnitudes to be extracted from experimental measurements.", "date": "2015-06-19", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2015-2246", "id_number": "CaltechAUTHORS:20190828-102324131", "isbn": "978-1-62410-364-3", "book_title": "31st AIAA Aerodynamic Measurement Technology and Ground Testing Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190828-102324131", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2015-2246", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2015-2246", "pub_year": "2015", "author_list": "Schmidt, B. E. and Shepherd, J. E." }, { "id": "https://authors.library.caltech.edu/records/ax041-mw050", "eprint_id": 90327, "eprint_status": "archive", "datestamp": "2023-09-15 06:08:09", "lastmod": "2023-10-23 21:23:22", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Cymbalist-N", "name": { "family": "Cymbalist", "given": "Niccolo" } }, { "id": "Dimotakis-P-E", "name": { "family": "Dimotakis", "given": "Paul" } } ] }, "title": "On autoignition-dominated supersonic combustion", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2015 American Institute of Aeronautics and Astronautics.", "abstract": "Supersonic combustion in hydrocarbon-fueled scramjets, in the lower limits of hypersonic flight Mach numbers, is expected to occur as autoignition-dominated distributed reactions. At relevant conditions, including leading to autoignition is not well-captured by detailed chemical-kinetic models at present. This paper introduces an evolution-variable manifold (EVM) framework for modeling autoignition-dominated distributed reactions in both compressible and incompressible flows. This framework combines a data-driven model for induction with a Lagrangian-reactor-generated (discretized) state-space manifold method for post-ignition combustion. As a first-order validation, EVM captures the temperature evolution in a rapidly-mixing well-stirred reactor (WSR).", "date": "2015-06", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "id_number": "CaltechAUTHORS:20181022-131635711", "isbn": "978-1-62410-362-9", "book_title": "45th AIAA Fluid Dynamics Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181022-131635711", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2015-2315", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2015-2315", "pub_year": "2015", "author_list": "Cymbalist, Niccolo and Dimotakis, Paul" }, { "id": "https://authors.library.caltech.edu/records/5brb8-pxp25", "eprint_id": 90326, "eprint_status": "archive", "datestamp": "2023-09-15 06:08:05", "lastmod": "2023-10-23 21:23:20", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Candler-G-V", "name": { "family": "Candler", "given": "Graham V." } }, { "id": "Subbareddy-P-K", "name": { "family": "Subbareddy", "given": "Pramod K." } }, { "id": "Cymbalist-N", "name": { "family": "Cymbalist", "given": "Niccolo" } }, { "id": "Dimotakis-P-E", "name": { "family": "Dimotakis", "given": "Paul" } } ] }, "title": "Large-Eddy Simulation of Autoignition-Dominated Supersonic Combustion", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2015 Graham V. Candler. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission. \n\nThis work was sponsored by the Air Force Office of Scientific Research under grants FA9550-12-1-0064. The views and conclusions contained herein are those of the author and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the AFOSR or the U.S. Government.\n\nPublished - Candler_CD.2015.AIAAP.LES_of_Autoignition-Dominated_Supersonic_Combustio.._.pdf
", "abstract": "The simulation of low-speed combustion flows is well established. However, at high-speed conditions where radical formation and ignition delay are important, there is much less experience with turbulent combustion modeling. In the present work, a novel evolution variable manifold (EVM) approach of Cymbalist and Dimotakis is implemented in a production CFO code and preliminary RANS and large-eddy simulations are computed for a hydrogen combustion test case. The EVM approach solves a scalar conservation equation for the induction time to represent ignition delay. The state or the combustion products is tabulated as a function of density, energy, mixture fraction, and the evolution variable. A thermodynamically-consistent numerical flux function is developed and the approach for coupling the EVM table to CFD is discussed. Initial simulations show that the EVM approach produces good agreement with full chemical kinetics and model simulations. Work remains to be done to improve the numerical stability, extend the grid, and increase the order or accuracy of the simulations.", "date": "2015-06", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "1-15", "id_number": "CaltechAUTHORS:20181022-130026482", "isbn": "978-1-62410-362-9", "book_title": "45th AIAA Fluid Dynamics Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181022-130026482", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-12-1-0064" } ] }, "other_numbering_system": { "items": [ { "id": "2015-3340", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2015-3340", "primary_object": { "basename": "Candler_CD.2015.AIAAP.LES_of_Autoignition-Dominated_Supersonic_Combustio.._.pdf", "url": "https://authors.library.caltech.edu/records/5brb8-pxp25/files/Candler_CD.2015.AIAAP.LES_of_Autoignition-Dominated_Supersonic_Combustio.._.pdf" }, "pub_year": "2015", "author_list": "Candler, Graham V.; Subbareddy, Pramod K.; et el." }, { "id": "https://authors.library.caltech.edu/records/btwp3-b8n58", "eprint_id": 90328, "eprint_status": "archive", "datestamp": "2023-09-15 06:08:15", "lastmod": "2023-10-23 21:23:24", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kartha-A", "name": { "family": "Kartha", "given": "Anand" } }, { "id": "Subbareddy-P-K", "name": { "family": "Subbareddy", "given": "Pramod K." } }, { "id": "Candler-G-V", "name": { "family": "Candler", "given": "Graham V." } }, { "id": "Dimotakis-P-E", "name": { "family": "Dimotakis", "given": "Paul" } } ] }, "title": "LES of Reacting Mixing Layers: Species Concentration Boundedness and Inflow Conditions", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2015 American Institute of Aeronautics and Astronautics. \n\nThis work was sponsored by the Air Force Office of Scientific Research under grants FA9550-12-1-0064 and FA9550-12-1-0461 and the Department of Energy. The views and conclusions contained herein are those of the author and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the AFOSR or the U.S. Government. This work was carried out in part using computing resources at the University of Minnesota Supercomputing Institute. We would also like to thank Sidharth G.S., Joesph Brock, Ross Choudary and Derek Dinzl for constructive discussions during the work.\n\nPublished - Kartha+.2015.AIAAP.LES_of_Reacting_Mixing_Layers.pdf
", "abstract": "The present work carries out large-eddy simulations of the low-speed, high-Reynolds number, chemically-reacting mixing layer experiments by Slessor et. al. In particular, we study the low-heat release case with prescribed turbulent inflow conditions. The objective of the present work is to gain insight into the physics of the reacting shear layer and to address some associated computational challenges. This set of experiments are at subsonic conditions and use hydrogen and fluorine as the fuel and oxidizer, respectively. The hypergolic reaction between H_2 and F_2, as it was run in the Slessor et al. experiments, is characterized by a large Damk\u00f6hler number, making the chemistry fast compared to the flow time scales: the product formation and temperature-rise in the flow is mixing-limited. In this work, we attempt to address the issue of overshoots and undershoots of species mass-frictions, often observed in LES of high-Reynolds number flows, by modifying the convective fluxes. We observe that the modified fluxes eliminate the global excursions of\nspecies mass-fraction concentration. A three dimensional simulation is performed by imposing synthetic turbulence at the inflow, generated using the digital filter approach of Klein et al., to mimic the experimental flow conditions. The velocity profiles, growth rate, and product thickness obtained from the simulations show a good match with the experimental data, but the peak value of temperature-rise is slightly over predicted.", "date": "2015-06", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "1-15", "id_number": "CaltechAUTHORS:20181022-132704070", "isbn": "978-1-62410-366-7", "book_title": "45th AIAA Fluid Dynamics Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181022-132704070", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-12-1-0064" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-12-1-0461" }, { "agency": "Department of Energy (DOE)" } ] }, "other_numbering_system": { "items": [ { "id": "2015-3207", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2015-3207", "primary_object": { "basename": "Kartha+.2015.AIAAP.LES_of_Reacting_Mixing_Layers.pdf", "url": "https://authors.library.caltech.edu/records/btwp3-b8n58/files/Kartha+.2015.AIAAP.LES_of_Reacting_Mixing_Layers.pdf" }, "pub_year": "2015", "author_list": "Kartha, Anand; Subbareddy, Pramod K.; et el." }, { "id": "https://authors.library.caltech.edu/records/5qr88-zs308", "eprint_id": 73047, "eprint_status": "archive", "datestamp": "2023-08-20 06:08:08", "lastmod": "2023-10-24 14:59:40", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Yang-Junho", "name": { "family": "Yang", "given": "Junho" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Hutchinson-Seth", "name": { "family": "Hutchinson", "given": "Seth" }, "orcid": "0000-0002-3949-6061" }, { "id": "Johnson-David", "name": { "family": "Johnson", "given": "David" } }, { "id": "Kise-Michio", "name": { "family": "Kise", "given": "Michio" } } ] }, "title": "Omnidirectional-vision-based estimation for containment detection of a robotic mower", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2015 IEEE. \n\nDate Added to IEEE Xplore: 02 July 2015. \n\nThis material is based on work supported by John Deere.", "abstract": "In this paper, we present an omnidirectional-vision-based localization and mapping system which can detect whether a robotic mower is contained in a permitted area. We exploit a robot-centric mapping framework that exploits a differential equation of motion of the landmarks, which are referenced with respect to the robot body frame. The estimator in our system generates a 3D point-based map with landmarks. Concurrently, the estimator defines a boundary of the mowing area with the estimated trajectory of the mower. The estimated boundary and the landmark map are provided for the estimation of the mowing location and for the containment detection. We validate the effectiveness of our system through numerical simulations and present the results of the outdoor experiment that we conducted with our robotic mower.", "date": "2015-05", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "6344-6351", "id_number": "CaltechAUTHORS:20161221-075702098", "isbn": "978-1-4799-6923-4", "book_title": "2015 IEEE International Conference on Robotics and Automation (ICRA)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161221-075702098", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/ICRA.2015.7140090", "pub_year": "2015", "author_list": "Yang, Junho; Chung, Soon-Jo; et el." }, { "id": "https://authors.library.caltech.edu/records/6b3wk-jy838", "eprint_id": 97979, "eprint_status": "archive", "datestamp": "2023-08-20 04:32:33", "lastmod": "2023-10-18 16:56:00", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Li-Jun", "name": { "family": "Li", "given": "Jun" } }, { "id": "Kwok-Kawai", "name": { "family": "Kwok", "given": "Kawai" }, "orcid": "0000-0001-6876-4267" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "S." }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Large-Strain Viscoelastic Constitutive Models for Thin Polyethylene Films", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2015 American Institute of Aeronautics and Astronautics.", "abstract": "This paper presents a constitutive model capable of predicting the thermoviscoelastic behavior of the balloon thin film StratoFilm subject to large strains up to yielding. The model is based on the free volume theory of nonlinear thermoviscoelasticity and extended to orthotropic membranes. An ingredient of the present approach is that the experimentally inaccessible out-of-plane material properties are determined by fitting the model predictions to the measured non-linear behavior of the film. Creep tests, uniaxial tension tests, and biaxial bubble tests are used to determine the material parameters. The model has been validated experimentally, against data obtained from uniaxial tension tests and biaxial cylindrical tests at a wide range of temperatures and strain rates spanning two orders of magnitude (0.01%/s ~ 1%/s).", "date": "2015-01-05", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2015-0194", "id_number": "CaltechAUTHORS:20190816-144341701", "isbn": "9781624103421", "book_title": "AIAA SciTech : 56th AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190816-144341701", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2015-0194", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2015-0194", "pub_year": "2015", "author_list": "Li, Jun; Kwok, Kawai; et el." }, { "id": "https://authors.library.caltech.edu/records/0123w-vgg70", "eprint_id": 97967, "eprint_status": "archive", "datestamp": "2023-08-20 04:32:21", "lastmod": "2023-10-18 16:55:25", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Arya-M", "name": { "family": "Arya", "given": "Manan" } }, { "id": "Lee-Nicolas", "name": { "family": "Lee", "given": "Nicolas" }, "orcid": "0000-0001-5500-1324" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Wrapping Thick Membranes with Slipping Folds", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2015 American Institute of Aeronautics and Astronautics. \n\nSupport from the Northrop Grumman Corporation is gratefully acknowledged. \n\nN. Lee was supported through this work by a postdoctoral fellowship from the W. M. Keck Institute for Space Studies.", "abstract": "A novel method of packaging finite-thickness membranes tightly and with high packaging efficiency is presented. This method allows the membrane to be packaged without extension and without plastic creasing. As such, initially flat membranes can be deployed to a flat state. Membrane thickness is accommodated by removing material along fold lines and exploiting the slipping deformation mechanism thus created. \n\nAlso presented are methods for prestressing and deploying membranes packaged according to this technique. Initial tests demonstrate packaging efficiencies of 73% without plastic deformation. Experimental deployment tests of a meter-scale model showed controlled deployment with unfolding forces of less than 0.6 N.", "date": "2015-01-05", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2015-0682", "id_number": "CaltechAUTHORS:20190816-144340621", "isbn": "9781624103452", "book_title": "AIAA SciTech : 2nd AIAA Spacecraft Structures Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190816-144340621", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Northrop Grumman Corporation" }, { "agency": "Keck Institute for Space Studies (KISS)" } ] }, "other_numbering_system": { "items": [ { "id": "2015-0682", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Keck-Institute-for-Space-Studies" } ] }, "doi": "10.2514/6.2015-0682", "pub_year": "2015", "author_list": "Arya, Manan; Lee, Nicolas; et el." }, { "id": "https://authors.library.caltech.edu/records/vccbr-9yn62", "eprint_id": 97978, "eprint_status": "archive", "datestamp": "2023-08-20 04:32:29", "lastmod": "2023-10-18 16:55:58", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Tumuklu-O", "name": { "family": "Tumuklu", "given": "Ozgur" } }, { "id": "Levin-D-A", "name": { "family": "Levin", "given": "Deborah A." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "J. M." }, "orcid": "0000-0003-3129-5035" } ] }, "title": "Shock-shock interactions for a double wedge configuration in different gases", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2015 American Institute of Aeronautics and Astronautics.", "abstract": "A kinetic, particle method has been used to model laminar shock-shock interactions of hypersonic flow over a 30/55-deg double-wedge configuration studied in the Hypervelocity Expansion Tube (HET) facility. The current study focuses on the investigation of Mach 7 nitrogen, air and argon flows for a stagnation enthalpy of 8.0 MJ/kg, conditions where thermochemical nonequilibrium is present. The simulations are found to reproduce many of the classic features related to Edney Type V strong shock interactions that include the attached, oblique shock formed over the first wedge, the detached bow shock from the second wedge, the strong separation zone, and the separation and reattachment shocks that cause complex features such as the triple point. As reported earlier,1 it was found that a full threedimensional model was required to simulate the heat flux and transient behavior of the nitrogen flow. In contrast, preliminary 2-D results of a reacting air flow case seem to indicate that the size of the separation length and the time required to reach steady state is much less than was found for the 2-D nitrogen flow model and comparison with measured heat fluxes and time-dependent shock profiles for air are in reasonable agreement. Lastly, to understand the effects of the internal modes on the shock structure, argon flow is also studied.", "date": "2015-01-05", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2015-1520", "id_number": "CaltechAUTHORS:20190816-144341618", "isbn": "9781624103438", "book_title": "AIAA SciTech : 53rd AIAA Aerospace Sciences Meeting", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190816-144341618", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2015-1520", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2015-1520", "pub_year": "2015", "author_list": "Tumuklu, Ozgur; Levin, Deborah A.; et el." }, { "id": "https://authors.library.caltech.edu/records/8vr3q-rbt13", "eprint_id": 97980, "eprint_status": "archive", "datestamp": "2023-08-20 04:32:47", "lastmod": "2023-10-18 16:56:02", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Sakovsky-M", "name": { "family": "Sakovsky", "given": "M." }, "orcid": "0000-0002-3683-8505" }, { "id": "Maqueda-I", "name": { "family": "Maqueda", "given": "I." } }, { "id": "Karl-C", "name": { "family": "Karl", "given": "C." } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "S." }, "orcid": "0000-0001-9373-3278" }, { "id": "Costantine-J", "name": { "family": "Costantine", "given": "J." } } ] }, "title": "Dual-Matrix Composite Wideband Antenna Structures for CubeSats", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2015 American Institute of Aeronautics and Astronautics. \n\nDr Jeremy Banik at AFRL and Dr Tom Murphey, formerly at AFRL, have provided the initial inspiration for this work and many helpful comments and suggestions. This research was supported by the AFOSR (award no. FA9550-13-1-0061, program manager Dr David Stargel).", "abstract": "A concept for a deployable high-performance antenna for CubeSats is presented. The detailed design of a conical log-spiral antenna with wideband operation between 250 500 MHz, a gain of above 5 dB, and circular polarization is performed using electromagnetic simulations. A structural concept using dual-matrix composites with soft hinge regions, allowing the antenna to be packaged into small volumes, is developed. An antenna prototype is fabricated using Astroquartz fibers in an epoxy matrix; a high-strain silicone matrix is used in the hinge regions. Structural and electromagnetic analyses are conducted and show good agreement with predicted performance thus demonstrating the validity of the proposed antenna concept.", "date": "2015-01-05", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2015-0944", "id_number": "CaltechAUTHORS:20190816-144341792", "isbn": "9781624103452", "book_title": "AIAA SciTech : 2nd AIAA Spacecraft Structures Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190816-144341792", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-13-1-0061" } ] }, "other_numbering_system": { "items": [ { "id": "2015-0944", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2015-0944", "pub_year": "2015", "author_list": "Sakovsky, M.; Maqueda, I.; et el." }, { "id": "https://authors.library.caltech.edu/records/k6k2k-w8z09", "eprint_id": 97965, "eprint_status": "archive", "datestamp": "2023-08-20 04:32:06", "lastmod": "2023-10-18 16:55:15", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Parziale-N-J", "name": { "family": "Parziale", "given": "N. J." }, "orcid": "0000-0001-9880-1727" }, { "id": "Schmidt-B-E", "name": { "family": "Schmidt", "given": "B. E." }, "orcid": "0000-0001-9193-7760" }, { "id": "Damazo-J-S", "name": { "family": "Damazo", "given": "J. S." }, "orcid": "0000-0002-4155-7177" }, { "id": "Wang-Patrick-S", "name": { "family": "Wang", "given": "P. S." } }, { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "H. G." }, "orcid": "0000-0002-4903-8419" }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "J. E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "Pulsed Laser Diode for Use as a Light Source for Short-Exposure, High-Frame-Rate Flow Visualization", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2015 American Institute of Aeronautics and Astronautics. \n\nThe authors would like to thank Bahram Valiferdowsi for help running T5. This work was an activity that was part of National Center for Hypersonic Laminar-Turbulent Research, sponsored by the Integrated Theoretical, Computational, and Experimental Studies for Transition Estimation and Control project, supported by the U.S. Air Force Office of Scientific Research and the National Aeronautics and Space Administration (FA9552-09-1-0341). Additionally, this work was supported in part of the Transition Delay in Hypervelocity Boundary Layers by Means of CO2/Acoustic Interactions project, sponsored by the Air Force Office of Scientific Research (FA9550-10-1-0491). J. Damazo was supported by an NDSEG Fellowship.", "abstract": "A pulsed laser diode (PLD) is demonstrated as a practical light source for high-speed digital schlieren and shearing-interferometric cinematogrpahy. Frame rates of greater than 300k fps with exposure times on the order of 10 ns have been achieved with an inexpensive and user-friendly setup. The light source has primarily been used in our laboratory to study nonsteady phenomena in high-speed gas flows. Examples are presented to illustrate the usefulness of the PLD as a light source with characteristics of a narrow band of wavelength, short exposure time, high frame-rate, and long pulse train duration.", "date": "2015-01-05", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2015-0530", "id_number": "CaltechAUTHORS:20190816-144340439", "isbn": "9781624103438", "book_title": "AIAA SciTech : 53rd AIAA Aerospace Sciences Meeting", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190816-144340439", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9552-09-1-0341" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-10-1-0491" }, { "agency": "National Defense Science and Engineering Graduate (NDSEG) Fellowship" } ] }, "other_numbering_system": { "items": [ { "id": "2015-0530", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2015-0530", "pub_year": "2015", "author_list": "Parziale, N. J.; Schmidt, B. E.; et el." }, { "id": "https://authors.library.caltech.edu/records/gdayh-9ed40", "eprint_id": 97981, "eprint_status": "archive", "datestamp": "2023-08-20 04:32:54", "lastmod": "2023-10-18 16:56:10", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Delapierre-M", "name": { "family": "Delapierre", "given": "M." } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "S." }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Spin-Stabilized Membrane Antenna Structures", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2015 American Institute of Aeronautics and Astronautics.", "abstract": "This paper explores the possibility of using spin-stabilized membrane structures for large phased array microwave antennas (typically L-Band or S-Band from 1 GHz to 4 GHz). The biggest challenge is to be able to sufficiently stabilize the system in order to limit its sensitivity to space disturbances (maneuvering, reaction wheels, and other imposed forces) and manufacturing imperfections. First, a flatness requirement for microwave antennas is derived. Then a frequency analysis of orthotropic flat structures spinning at different angular velocities and with different bending stiffnesses is carried out. These analyses, together with finite element simulations, are used to derive scaling laws to study the behavior of structures spinning in space. A test case, based on a spinning structure perturbed at the hub, is considered. An analytical solution of the free vibration of this test case is compared to the results of finite-element method simulations with Abaqus/Standard. Finally a test setup to study the dynamics of scaled spinning membranes in the laboratory is presented. Gravity effects in such an experiment are expected to be small.", "date": "2015-01-05", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, Virginia", "pagerange": "Art. No. 2015-1403", "id_number": "CaltechAUTHORS:20190816-144341883", "isbn": "9781624103452", "book_title": "AIAA SciTech : 2nd AIAA Spacecraft Structures Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190816-144341883", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2015-1403", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2015-1403", "pub_year": "2015", "author_list": "Delapierre, M. and Pellegrino, S." }, { "id": "https://authors.library.caltech.edu/records/xp9yr-geg68", "eprint_id": 97966, "eprint_status": "archive", "datestamp": "2023-08-20 04:32:13", "lastmod": "2023-10-18 16:55:17", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Parziale-N-J", "name": { "family": "Parziale", "given": "N. J." }, "orcid": "0000-0001-9880-1727" }, { "id": "Jewell-J-S", "name": { "family": "Jewell", "given": "J. S." }, "orcid": "0000-0002-4047-9998" }, { "id": "Leyva-I-A", "name": { "family": "Leyva", "given": "I. A." } }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "J. E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "Effects of Shock-Tube Cleanliness on Slender-Body Hypersonic Instability and Transition Studies at High-Enthalpy", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2015 American Institute of Aeronautics and Astronautics. \n\nThe authors would like to thank Bahram Valiferdowsi for help running T5 and Ross Wagnild for help with the program to compute the run conditions. This work was an activity that was part of National Center for Hypersonic Laminar-Turbulent Research, sponsored by the \"Integrated Theoretical, Computational, and Experimental Studies for Transition Estimation and Control\" project, supported by the U.S. Air Force Office of Scientific Research and the National Aeronautics and Space Administration (FA9552-09-1-0341). Additionally, this work was part of the \"Transition Delay in Hypervelocity Boundary Layers by Means of CO_2/Acoustic Interactions\" project, sponsored by the Air Force Office of Scientific Research (FA9550-10-1-0491). J. S. Jewell received additional support from the National Defense Science and Engineering Graduate Fellowship and the Jack Kent Cooke Foundation.", "abstract": "A series of slender-body hypervelocity boundary-layer instability and transition experiments were performed in the Caltech T5 Reflected-Shock Tunnel. During this campaign, it became clear that the condition of the T5 shock tube would significantly affect the consistency of the instability and transition measurements; a regimen of cleaning was iterated on until satisfactory repeatability was achieved. In this work, a description of the cleaning regimen is given. Additionally, boundary-layer instability measurements and a statistical analysis of the boundary-layer transition scatter are presented for experiments before and after cleaning regimen implementation.", "date": "2015-01-05", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2015-1786", "id_number": "CaltechAUTHORS:20190816-144340522", "isbn": "9781624103438", "book_title": "AIAA SciTech : 53rd AIAA Aerospace Sciences Meeting", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190816-144340522", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9552-09-1-0341" }, { "agency": "NASA" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-10-1-0491" }, { "agency": "National Defense Science and Engineering Graduate (NDSEG) Fellowship" }, { "agency": "Jack Kent Cooke Foundation" } ] }, "other_numbering_system": { "items": [ { "id": "2015-1786", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2015-1786", "pub_year": "2015", "author_list": "Parziale, N. J.; Jewell, J. S.; et el." }, { "id": "https://authors.library.caltech.edu/records/5ngnb-pc182", "eprint_id": 97982, "eprint_status": "archive", "datestamp": "2023-08-20 04:33:02", "lastmod": "2023-10-18 16:56:12", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ning-Xin", "name": { "family": "Ning", "given": "Xin" }, "orcid": "0000-0002-9432-3665" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Buckling Analysis of Axially Loaded Corrugated Cylindrical Shells", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2015 American Institute of Aeronautics and Astronautics. \n\nWe thank Dr. Katia Bertoldi for providing her presentations in the 2014 CISM short courses. We also thank Drs. Francisco L\u00f3pez Jim\u00e9nez and Ryan Elliott for helpful discussions on the Bloch wave method.", "abstract": "Buckling analyses of heavily corrugated cylindrical shells based on detailed full finite element models are usually computationally expensive. To address this issue, we have pro- posed an efficient computational method of predicting the onset of buckling for corrugated cylindrical shells which builds on the Bloch wave method for infinitely periodic structures. We modified the traditional Bloch wave method in order to analyze the buckling of rotationally periodic shell structures. We have developed an efficient algorithm to perform our modified Bloch wave method. The buckling behavior of composite corrugated cylindrical shells with a range of numbers of corrugations was analyzed. Linear and nonlinear buckling analyses of detailed full finite element models were also performed and compared to our method. Comparisons showed that our modified Bloch wave method was able to obtain highly accurate buckling loads and it was able to capture both global and local buckling modes. It was also found that the computational time required by our modified Bloch wave method did not scale up as the number of corrugations increased.", "date": "2015-01-05", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2015-1435", "id_number": "CaltechAUTHORS:20190816-144341971", "isbn": "9781624103421", "book_title": "AIAA SciTech : 56th AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190816-144341971", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2015-1435", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2015-1435", "pub_year": "2015", "author_list": "Ning, Xin and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/m2pyj-rsc38", "eprint_id": 99319, "eprint_status": "archive", "datestamp": "2023-08-20 04:31:27", "lastmod": "2023-10-18 18:13:42", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Whalen-E-A", "name": { "family": "Whalen", "given": "Edward A." } }, { "id": "Lacy-D-S", "name": { "family": "Lacy", "given": "Douglas" } }, { "id": "Lin-John-C", "name": { "family": "Lin", "given": "John C." }, "orcid": "0000-0003-2794-184X" }, { "id": "Andino-M-Y", "name": { "family": "Andino", "given": "Marlyn Y." } }, { "id": "Washburn-A-E", "name": { "family": "Washburn", "given": "Anthony E." } }, { "id": "Graff-E-C", "name": { "family": "Graff", "given": "Emilio" } }, { "id": "Wygnanski-I-J", "name": { "family": "Wygnanski", "given": "Israel J." } } ] }, "title": "Performance Enhancement of a Full-Scale Vertical Tail Model Equipped with Active Flow Control", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2015 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 3 Jan 2015. \n\nThis multi-organizational and multidisciplinary teaming effort involved many people who provided valuable contributions through their detailed work and/or expert guidance. The contributors have come from within the NASA/Boeing team and their partners. The NASA/Boeing collaboration was executed through a Space Act Agreement (Annex 8 to SAA1-1155). The NASA ERA project sponsored the sweeping jet AFC technology via Caltech (TEAMS 2 Contract NNL12AA09C) and the University of Arizona (direct subcontract). The ERA project also sponsored the wind tunnel test at NFAC (NIPR# NNL12AA13T). The authors would like to thank key personnel in the following organizations for their excellent support during the course of this investigation: Boeing Commercial Airplanes: Kate Nowicki (technology manager), John Brandt (stability & control), Kyle Ford (loads & dynamics), and Helen Mooney (aerodynamics).\n\nPublished - 20150006853.pdf
", "abstract": "This paper describes wind tunnel test results from a joint NASA/Boeing research effort to advance active flow control (AFC) technology to enhance aerodynamic efficiency. A full-scale Boeing 757 vertical tall model equipped with sweeping jet actuators was tested at the National Full-Scale Aerodynamics Complex (NIFAC) 40- by 80-Foot Wind Tunnel (40x80) at NASA Ames Research Center. The model was tested at a nominal airspeed of 100 knots and across rudder deflections and sideslip angles that covered the vertical tail flight envelope. A successful demonstration or AFC-enhanced vertical tail technology was achieved. A 31-actuator configuration significantly increased side force (by greater than 20%) at a maximum rudder deflection of 30\u00b0. The successful demonstration of this application has cleared the way for a flight demonstration on the Boeing 757 ecoDemonstrator in 2015.", "date": "2015-01-03", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2015-0784", "id_number": "CaltechAUTHORS:20191017-075901660", "isbn": "978-1-62410-343-8", "book_title": "53rd AIAA Aerospace Sciences Meeting", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191017-075901660", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA", "grant_number": "NNL12AA09C" }, { "agency": "University of Arizona" }, { "agency": "NASA", "grant_number": "NNL12AA13T" } ] }, "other_numbering_system": { "items": [ { "id": "2015-0784", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2015-0784", "primary_object": { "basename": "20150006853.pdf", "url": "https://authors.library.caltech.edu/records/m2pyj-rsc38/files/20150006853.pdf" }, "pub_year": "2015", "author_list": "Whalen, Edward A.; Lacy, Douglas; et el." }, { "id": "https://authors.library.caltech.edu/records/8fdn8-vn573", "eprint_id": 99320, "eprint_status": "archive", "datestamp": "2023-08-20 04:31:14", "lastmod": "2023-10-18 18:13:45", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bradford-S-C", "name": { "family": "Bradford", "given": "Samuel Case" } }, { "id": "Hofmann-D-C", "name": { "family": "Hofmann", "given": "Douglas C." } }, { "id": "Roberts-S-N", "name": { "family": "Roberts", "given": "Scott N." } }, { "id": "Wojnar-C-S", "name": { "family": "Wojnar", "given": "Charles S." } }, { "id": "Kochmann-D-M", "name": { "family": "Kochmann", "given": "Dennis M." }, "orcid": "0000-0002-9112-6615" } ] }, "title": "Energy-Efficient Active Reflectors with Improved Mechanical Stability", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2015 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 2 Jan 2015.", "abstract": "Active reflectors use an array of distributed actuators to control static surface deformations. In addition to meeting mission requirements with lower mass and lower costs, an active reflector adds robustness to a mission design by allowing for correction of unexpected orbital deformations.\nTo control the wavefront of an active reflector, first the surface aberration is measured (via, e.g., a\nShack-Hartmann sensor, direct imaging of the reflector surface, interferometric metrology, image-based\nPSF estimation, or other methods). Based on an actuator sensitivity matrix, a voltage\nprofile is calculated that best reduces the observed aberration. In addition to controlling the\nstatic wavefront, piezoelectric actuators can easily be used to control structural vibrations in\nthe frequency ranges of interest for active reflectors (50 to 2000Hz). Operational vibrations (e.g.,\nmicrodynamics, ACS-induced vibrations, slew, thermally-induced stick-slip events) can effectively\nbe rejected from the reflector system. Launch load vibrations are typically drivers for structural\nrequirements, and typical mission concepts would have reflector actuators unpowered or shorted\nduring launch. By incorporating a vibration control system into the actuator power circuitry,\nlaunch loads on the fragile reflector structure can be significantly reduced.\nBy improving the electromechanical coupling and deliberately operating in a new nonlinear\npiezoelectric regime, we have optimized the surface correction and use the same actuators developed\nfor surface control as structural control elements. This has yielded improved performance\nin terms of power draw and also enabled vibration suppression for launch load and operational\ndisturbances.", "date": "2015-01-02", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2015-1400", "id_number": "CaltechAUTHORS:20191017-080904981", "isbn": "978-1-62410-345-2", "book_title": "2nd AIAA Spacecraft Structures Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191017-080904981", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2015-1400", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2015-1400", "pub_year": "2015", "author_list": "Bradford, Samuel Case; Hofmann, Douglas C.; et el." }, { "id": "https://authors.library.caltech.edu/records/v8xr6-vs182", "eprint_id": 72429, "eprint_status": "archive", "datestamp": "2023-08-20 04:28:22", "lastmod": "2023-10-23 22:33:39", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bandyopadhyay-S", "name": { "family": "Bandyopadhyay", "given": "Saptarshi" } }, { "id": "Subramanian-G-P", "name": { "family": "Subramanian", "given": "Giri P." } }, { "id": "Foust-Rebecca", "name": { "family": "Foust", "given": "Rebecca" }, "orcid": "0000-0003-1470-1716" }, { "id": "Morgan-Daniel", "name": { "family": "Morgan", "given": "Daniel" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Hadaegh-F-Y", "name": { "family": "Hadaegh", "given": "Fred Y." } } ] }, "title": "A Review of Impending Small Satellite Formation Flying Missions", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2015 American Institute of Aeronautics and Astronautics, Inc.\n\nThe authors would like to thank Dr. Tom Cwik for his guidance and constructive comments. The authors would also like to thank D. Hanley, J. Puig, and H.-B. Yoon for their valuable inputs. This work was supported by the Jet Propulsion Laboratory and the NASA Office of the Chief Technologist Space Technology Research Fellowship Program. Government sponsorship is acknowledged. This research was\ncarried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.", "abstract": "Small satellites, like popular nanosatellite platforms called CubeSats, are suitable for formation flying missions because of their modular nature and low cost. This paper presents a review of thirty-nine missions, using multiple small satellites, in various stages of development. These missions are categorized based on their mission type, mission status, number of satellites, leading organization, funding source, and requirement for constellation or\nformation flying. We conclude that Earth science related missions are the most popular, while most multi-satellite missions only require a constellation. Although six missions aim to demonstrate formation flying capability in space using two to three small satellites, there are currently only two formation flying missions planning to use four or more small satellites.", "date": "2015-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics (AIAA)", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2015-1623", "id_number": "CaltechAUTHORS:20161130-083605025", "isbn": "978-1-62410-343-8", "book_title": "53rd AIAA Aerospace Sciences Meeting", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161130-083605025", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA Space Technology Research Fellowship" }, { "agency": "NASA/JPL/Caltech" } ] }, "other_numbering_system": { "items": [ { "id": "2015-1623", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2015-1623", "pub_year": "2015", "author_list": "Bandyopadhyay, Saptarshi; Subramanian, Giri P.; et el." }, { "id": "https://authors.library.caltech.edu/records/88a44-wnr37", "eprint_id": 72458, "eprint_status": "archive", "datestamp": "2023-08-20 04:28:27", "lastmod": "2023-10-23 22:35:47", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bandyopadhyay-S", "name": { "family": "Bandyopadhyay", "given": "Saptarshi" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Hadaegh-F-Y", "name": { "family": "Hadaegh", "given": "Fred Y." } } ] }, "title": "Attitude Control and Stabilization of Spacecraft with a Captured Asteroid", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2015 California Institute of Technology. \n\nThe authors would like to thank A. Miguel San Martin and Gurkipal Singh for their valuable inputs. This research was supported by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.\n\nPublished - AsteroidAIAAPaperv17.pdf
", "abstract": "National Aeronautics and Space Administration's Asteroid Redirect Mission (ARM) aims to capture a Near Earth Orbit (NEO) asteroid or a piece of a large asteroid and transport it to the Earth{Moon system. In this paper, we provide a detailed analysis\nof one of the main control challenges for the first ARM mission concept, namely despinning and three-axis stabilizing the asteroid and spacecraft combination after the ARM spacecraft captures the tumbling NEO asteroid. We first show that control laws, which explicitly use the dynamics of the system in their control law equation, encounter a fundamental limitation due to modeling uncertainties. We show that in the presence of large\nmodeling uncertainties, the resultant disturbance torque for such control laws may well exceed the maximum control torque of the conceptual ARM spacecraft. We then numerically compare the performance of three viable control laws: the robust nonlinear tracking control law, the adaptive nonlinear tracking control law, and the simple derivative plus proportional-derivative linear control strategy. We conclude that under very small mod-\neling uncertainties, which can be achieved using online system identification, the robust nonlinear tracking control law guarantees exponential convergence to the fuel-optimal reference trajectory and hence consumes the least fuel. On the other hand, in the presence of large modeling uncertainties, measurement errors, and actuator saturations, the best strategy for stabilizing the asteroid and spacecraft combination is to first despin the system using a derivative (rate damping) linear control law and then stabilize the system in the desired orientation using the simple proportional-derivative linear control law. More-over, the fuel consumed by the conceptual ARM spacecraft using these control strategies is upper bounded by 300 kg for the nominal range of NEO asteroid parameters. We conclude this paper with specific design guidelines for the ARM spacecraft for efficiently stabilizing the tumbling NEO asteroid and spacecraft combination.", "date": "2015-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics (AIAA)", "id_number": "CaltechAUTHORS:20161130-140551043", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161130-140551043", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2015-0596", "primary_object": { "basename": "AsteroidAIAAPaperv17.pdf", "url": "https://authors.library.caltech.edu/records/88a44-wnr37/files/AsteroidAIAAPaperv17.pdf" }, "pub_year": "2015", "author_list": "Bandyopadhyay, Saptarshi; Chung, Soon-Jo; et el." }, { "id": "https://authors.library.caltech.edu/records/5gyhs-m6937", "eprint_id": 72475, "eprint_status": "archive", "datestamp": "2023-08-20 04:28:35", "lastmod": "2023-10-23 22:38:34", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Subramanian-G-P", "name": { "family": "Subramanian", "given": "Giri P." } }, { "id": "Foust-Rebecca", "name": { "family": "Foust", "given": "Rebecca" }, "orcid": "0000-0003-1470-1716" }, { "id": "Chen-Derek", "name": { "family": "Chen", "given": "Derek" } }, { "id": "Chan-Stanley", "name": { "family": "Chan", "given": "Stanley" } }, { "id": "Taleb-Younes", "name": { "family": "Taleb", "given": "Younes" } }, { "id": "Rogers-Dayne-L", "name": { "family": "Rogers", "given": "Dayne L." } }, { "id": "Kokkat-Jobin", "name": { "family": "Kokkat", "given": "Jobin" } }, { "id": "Bandyopadhyay-S", "name": { "family": "Bandyopadhyay", "given": "Saptarshi" } }, { "id": "Morgan-Daniel", "name": { "family": "Morgan", "given": "Daniel" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Hadaegh-F-Y", "name": { "family": "Hadaegh", "given": "Fred Y." } } ] }, "title": "Information-Driven Systems Engineering Study of a Formation Flying Demonstration Mission using Six CubeSats", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2015 American Institute of Aeronautics and Astronautics. \n\nThis work was supported by the Jet Propulsion Laboratory and the NASA Office of the Chief Technologist's Space Technology Research Fellowship Program. Government sponsorship is acknowledged. This research was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the NASA. Additional thanks to Professor Grace Gao for allowing us to use her lab's equipment for GPS testing, and to Dr. Tom Cwik for his guidance and constructive comments.", "abstract": "Small satellites are suitable for formation flying missions where a large number of spacecraft serve as distributed sensors for applications like synthetic aperture radar, interferometry, etc. A survey of existing or proposed small satellite missions concludes that there is a dearth of formation flying missions using four or more spacecraft that require formation maintenance. This paper presents a systems engineering based design of a formation flying technology demonstration mission that requires precise formation maintenance and reconfigurations and highlights the challenges that need to be overcome for its successful implementation. The goal of this paper is to provide directions for future research and development in spacecraft formation flying technologies.", "date": "2015-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics (AIAA)", "id_number": "CaltechAUTHORS:20161130-153238963", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161130-153238963", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA Space Technology Research Fellowship" }, { "agency": "NASA/JPL/Caltech" } ] }, "other_numbering_system": { "items": [ { "id": "2015-2043", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2015-2043", "pub_year": "2015", "author_list": "Subramanian, Giri P.; Foust, Rebecca; et el." }, { "id": "https://authors.library.caltech.edu/records/6w8pf-agr93", "eprint_id": 74287, "eprint_status": "archive", "datestamp": "2023-08-20 04:28:45", "lastmod": "2023-10-24 22:17:04", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Gade-Shripad", "name": { "family": "Gade", "given": "Shripad" } }, { "id": "Paranjape-A-A", "name": { "family": "Paranjape", "given": "Aditya A." }, "orcid": "0000-0002-3164-3215" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Herding a Flock of Birds Approaching an Airport Using an Unmanned Aerial Vehicle", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2015 American Institute of Aeronautics and Astronautics.", "abstract": "The problem of herding a flock of birds is posed in a graph theoretic framework. A novel algorithm, called the n-wavefront algorithm, Is developed for enabling a single unmanned aerial vehicle to herd a flock of birds to a desired point. The technique is applied to the problem of diverting a flock of birds approaching an airport away from a protected zone around the airport. The n-wavefront algorithm is demonstrated in simulation and compared with existing strategies using graph-based metrics.", "date": "2015-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics (AIAA)", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2015-1540", "id_number": "CaltechAUTHORS:20170214-070946630", "isbn": "978-1-5108-0109-7", "book_title": "AIAA Guidance, Navigation, and Control Conference 2015", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170214-070946630", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2015-1540", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2015-1540", "pub_year": "2015", "author_list": "Gade, Shripad; Paranjape, Aditya A.; et el." }, { "id": "https://authors.library.caltech.edu/records/qeab6-gff42", "eprint_id": 78413, "eprint_status": "archive", "datestamp": "2023-08-20 04:17:52", "lastmod": "2023-10-26 00:04:49", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Jewell-J-S", "name": { "family": "Jewell", "given": "J. S." }, "orcid": "0000-0002-4047-9998" }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "J. E." }, "orcid": "0000-0003-3181-9310" }, { "id": "Leyva-I-A", "name": { "family": "Leyva", "given": "I. A." } } ] }, "title": "Shock Tunnel Operation and Correlation of Boundary Layer Transition on a Cone in Hypervelocity Flow", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2015 Springer International Publishing Switzerland. \n\nThe authors thank the T5 group members: Prof. Hans Hornung, Mr. Nick Parziale, andMr. Bahram Valiferdowsi; Dr. RossWagnild for substantial assistance with the flow and boundary layer analysis; and Miss Elizabeth Jewell for her statistical advice. This project was sponsored by the Air Force Office of Scientific Research under award number FA9550-10-1-0491 (J. Schmisseur, program manager). The views expressed herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of AFOSR or the U.S. Government.", "abstract": "The Caltech T5 reflected shock tunnel is used to produce hypervelocity flow over a range of velocities and pressures by varying the test gas and operating parameters of reservoir enthalpy (hres) and reservoir pressure (Pres). One area of research in T5 is the measurement of boundary layer behavior and transition from laminar to turbulent flow on a smooth 5-degree half-angle cone [3, 1, 11].", "date": "2015", "date_type": "published", "publisher": "Springer", "place_of_pub": "Cham, Switzerland", "pagerange": "723-728", "id_number": "CaltechAUTHORS:20170621-110733093", "isbn": "978-3-319-16834-0", "book_title": "29th International Symposium on Shock Waves", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170621-110733093", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-10-1-0491" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Bonazza-R", "name": { "family": "Bonazza", "given": "R." } }, { "id": "Ranjan-D", "name": { "family": "Ranjan", "given": "D." } } ] }, "doi": "10.1007/978-3-319-16835-7_116", "pub_year": "2015", "author_list": "Jewell, J. S.; Shepherd, J. E.; et el." }, { "id": "https://authors.library.caltech.edu/records/g95w4-86b94", "eprint_id": 78408, "eprint_status": "archive", "datestamp": "2023-08-20 04:17:38", "lastmod": "2023-10-26 00:04:38", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Schmidt-B-E", "name": { "family": "Schmidt", "given": "B. E." }, "orcid": "0000-0001-9193-7760" }, { "id": "Bobbitt-B", "name": { "family": "Bobbitt", "given": "B." } }, { "id": "Parziale-N-J", "name": { "family": "Parziale", "given": "N. J." }, "orcid": "0000-0001-9880-1727" }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "J. E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "Experiments in a Combustion-Driven Shock Tube with an Area Change", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2015 Springer International Publishing Switzerland.", "abstract": "Shock tubes are versatile and useful tools for studying high temperature gas dynamics and the production of hypervelocity flows. High shock speeds are desirable for creating higher enthalpy, pressure, and temperature in the test gas which makes the study of thermo-chemical effects on fluid dynamics possible. Independent of construction and operational cost, free-piston drivers, such as the one used in the T5 facility at Caltech, give the best performance [3]. The high operational cost and long turnaround time of such a facility make a more economical option desirable for smaller-scale testing.", "date": "2015", "date_type": "published", "publisher": "Springer", "place_of_pub": "Cham, Switzerland", "pagerange": "331-336", "id_number": "CaltechAUTHORS:20170621-104244755", "isbn": "978-3-319-16834-0", "book_title": "29th International Symposium on Shock Waves", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170621-104244755", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Bonazza-R", "name": { "family": "Bonazza", "given": "R." } }, { "id": "Ranjan-D", "name": { "family": "Ranjan", "given": "D." } } ] }, "doi": "10.1007/978-3-319-16835-7_51", "pub_year": "2015", "author_list": "Schmidt, B. E.; Bobbitt, B.; et el." }, { "id": "https://authors.library.caltech.edu/records/vpz67-rb434", "eprint_id": 78430, "eprint_status": "archive", "datestamp": "2023-08-20 04:17:59", "lastmod": "2023-10-26 00:05:36", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "L\u00f3pez-Ortega-A", "name": { "family": "L\u00f3pez-Ortega", "given": "A." } }, { "id": "Lombardini-Manuel", "name": { "family": "Lombardini", "given": "M." } }, { "id": "Barton-Philip-T", "name": { "family": "Barton", "given": "P. T." } }, { "id": "Pullin-D-I", "name": { "family": "Pullin", "given": "D. I." } }, { "id": "Meiron-D-I", "name": { "family": "Meiron", "given": "D. I." }, "orcid": "0000-0003-0397-3775" } ] }, "title": "Richtmyer-Meshkov Instability at Solid-Gas Interfaces", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2015 Springer International Publishing Switzerland. \n\nThis work was partially supported by the Department of Energy National Nuclear Security Administration under Award Number DE-FC52-08NA28613.", "abstract": "The impact of a shock-wave onto a perturbed interface separating materials of different density and initially at rest in a laboratory frame of reference is described as a Richtmer-Meshkov (RM) flow, following Richtmyer [1], who obtained a numerical solution to the linearized equations for perfect fluids using an impulsive model, and Meshkov [2], who performed shock-tube experiments for gaseous materials.", "date": "2015", "date_type": "published", "publisher": "Springer", "place_of_pub": "Cham, Switzerland", "pagerange": "1131-1136", "id_number": "CaltechAUTHORS:20170621-144124277", "isbn": "978-3-319-16837-1", "book_title": "29th International Symposium on Shock Waves", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170621-144124277", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Department of Energy (DOE) National Nuclear Security Administration", "grant_number": "DE-FC52-08NA28613" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Bonazza-Ricardo", "name": { "family": "Bonazza", "given": "Ricardo" } }, { "id": "Devesh-Ricardo", "name": { "family": "Devesh", "given": "Ricardo" } } ] }, "doi": "10.1007/978-3-319-16838-8_54", "pub_year": "2015", "author_list": "L\u00f3pez-Ortega, A.; Lombardini, M.; et el." }, { "id": "https://authors.library.caltech.edu/records/xjnfb-xkt10", "eprint_id": 78410, "eprint_status": "archive", "datestamp": "2023-08-20 04:17:45", "lastmod": "2023-10-26 00:04:43", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Parziale-N-J", "name": { "family": "Parziale", "given": "N. J." }, "orcid": "0000-0001-9880-1727" }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "J. E." }, "orcid": "0000-0003-3181-9310" }, { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "H. G." }, "orcid": "0000-0002-4903-8419" } ] }, "title": "Geometric Acoustics in High-Speed Boundary Layers", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2015 Springer International Publishing Switzerland.", "abstract": "A key mechanism responsible for the instability of high-speed boundary layers are the high-frequency modes discovered by Mack [1]. These modes are primarily acoustic in nature, are always present if the edge Mach number is sufficiently large, and are the dominant instability mechanism when the wall temperature is sufficiently low compared to the recovery temperature.", "date": "2015", "date_type": "published", "publisher": "Springer", "place_of_pub": "Cham, Switzerland", "pagerange": "711-716", "id_number": "CaltechAUTHORS:20170621-105808727", "isbn": "978-3-319-16834-0", "book_title": "29th International Symposium on Shock Waves", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170621-105808727", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Bonazza-R", "name": { "family": "Bonazza", "given": "R." } }, { "id": "Ranjan-D", "name": { "family": "Ranjan", "given": "D." } } ] }, "doi": "10.1007/978-3-319-16835-7_114", "pub_year": "2015", "author_list": "Parziale, N. J.; Shepherd, J. E.; et el." }, { "id": "https://authors.library.caltech.edu/records/1yn2c-tme67", "eprint_id": 78406, "eprint_status": "archive", "datestamp": "2023-08-20 04:17:31", "lastmod": "2023-10-26 00:04:31", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Rabinovitch-J", "name": { "family": "Rabinovitch", "given": "J." }, "orcid": "0000-0002-1914-7964" }, { "id": "Blanquart-G", "name": { "family": "Blanquart", "given": "G." }, "orcid": "0000-0002-5074-9728" } ] }, "title": "A Computationally Efficient Approach to Hypersonic Reacting Flows", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2015 Springer International Publishing Switzerland.", "abstract": "Reproducing hypersonic flight conditions in ground based facilities is a very challenging problem due to the high enthalpies required in the test gas, while simultaneously trying to match the post shock gas composition seen in flight. Experimental facilities have made significant progress in reproducing accurately hypersonic flows, but these facilities generally face issues associated with high operating costs and relatively short and noisy test times. This necessitates the need for high fidelity numerical simulations to aid with the investigation of these flows.", "date": "2015", "date_type": "published", "publisher": "Springer", "place_of_pub": "Cham", "pagerange": "173-178", "id_number": "CaltechAUTHORS:20170621-102011434", "isbn": "978-3-319-16835-7", "book_title": "29th International Symposium on Shock Waves", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170621-102011434", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Bonazza-R", "name": { "family": "Bonazza", "given": "Riccardo" } }, { "id": "Ranjan-D", "name": { "family": "Ranjan", "given": "Devesh" } } ] }, "doi": "10.1007/978-3-319-16835-7_25", "pub_year": "2015", "author_list": "Rabinovitch, J. and Blanquart, G." }, { "id": "https://authors.library.caltech.edu/records/q6gsz-bxg73", "eprint_id": 78235, "eprint_status": "archive", "datestamp": "2023-08-20 04:16:47", "lastmod": "2024-01-13 20:28:26", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Folding and Deployment of Thin Shell Structures", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2015 CISM Udine. \n\nFinancial support from AFOSR award no. FA9550-13-1-0061 (program manager Dr David Stargel) is acknowledged.", "abstract": "Thin shells made of high modulus material are widely used as lightweight deployable space structures. The focus of this chapter is the most basic deployable thin shell structure, namely a straight, transversely curved strip known as a tape spring. Following a review of the materials used for the construction of deployable thin shell structures, including constitutive models and failure criteria developed specifically for this type of structures, this chapter provides an introduction to the mechanics of tape springs and tape spring hinges. Finite element techniques to model deployable structures containing tape springs are presented and the ability of these models to accurately simulate experimentally observed behavior is demonstrated. These tools can be used to design structures able to achieve specific behaviors. As an example, the design of a two-hinge boom that can be wrapped around a small spacecraft without any damage, and can dynamically deploy and smoothly latch into the deployed configuration is presented.", "date": "2015", "date_type": "published", "publisher": "Springer", "place_of_pub": "New York, NY", "pagerange": "179-267", "id_number": "CaltechAUTHORS:20170615-080812634", "isbn": "978-3-7091-1876-4", "book_title": "Extremely Deformable Structures", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170615-080812634", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-13-1-0061" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Bigoni-D", "name": { "family": "Bigoni", "given": "Davide" } } ] }, "doi": "10.1007/978-3-7091-1877-1_5", "pub_year": "2015", "author_list": "Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/vbjvz-p1834", "eprint_id": 53331, "eprint_status": "archive", "datestamp": "2023-08-20 04:00:11", "lastmod": "2024-01-13 16:13:27", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "Hans G." }, "orcid": "0000-0002-4903-8419" } ] }, "title": "Mach Reflection in Steady Flow. I. Mikhail Ivanov's Contributions, II. Caltech Stability Experiments", "ispublished": "unpub", "full_text_status": "public", "keywords": "Mach reflection, hysteresis, viscosity", "note": "\u00a9 2014 AIP Publishing LLC.\n\nFor providing the files for the figures from the publications of Ivanov and his co\u2013workers I wish to thank the\nInstitute of Theoretical and Applied Mechanics of the Siberian Branch of the Russian Academy of Science (ITAM). In\nparticular Y. A. Bondar and G. V. Shoev have helped me enormously. I also wish to acknowledge the technical support\nof Bahram Valiferdowsi with the experiments in the Caltech Ludwieg Tube. Financial support for the experiments at\nCaltech was provide by the AFOSR. The AOARD supported my attendance at the Symposium.\n\nPublished - 1.4902753.pdf
", "abstract": "To honor the memory of our friend and colleague Mikhail Ivanov a review of his great contributions to the understanding of the various phenomena associated with steady-flow shock wave reflection is presented. Of course, he has contributed much more widely than that, but I will restrict myself to this part of his work, because it is what I understand best. In particular, his computational and experimental demonstration of hysteresis in the transition between regular and Mach reflection, and his resolution of the difficulties associated with the triple point in weak Mach reflection in terms of the effects of viscosity and heat conduction are reviewed. Finally, some experimental results are presented that demonstrate that, in the dual-solution domain, Mach reflection is more stable than regular reflection.", "date": "2014-12-09", "date_type": "published", "publisher": "American Institute of Physics", "place_of_pub": "Melville, NY", "pagerange": "1384-1393", "id_number": "CaltechAUTHORS:20150108-093434424", "isbn": "978-0-7354-1265-1", "book_title": "Proceedings of the 29th International Symposium on Rarefied Gas Dynamics", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150108-093434424", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Fan-J", "name": { "family": "Fan", "given": "Jing" } } ] }, "doi": "10.1063/1.4902753", "primary_object": { "basename": "1.4902753.pdf", "url": "https://authors.library.caltech.edu/records/vbjvz-p1834/files/1.4902753.pdf" }, "pub_year": "2014", "author_list": "Hornung, Hans G." }, { "id": "https://authors.library.caltech.edu/records/fbeny-5mv56", "eprint_id": 108563, "eprint_status": "archive", "datestamp": "2023-08-20 03:55:54", "lastmod": "2023-10-23 17:08:40", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Capuano-F", "name": { "family": "Capuano", "given": "F." } }, { "id": "Coppola-G", "name": { "family": "Coppola", "given": "G." } }, { "id": "Balarac-G", "name": { "family": "Balarac", "given": "G." } }, { "id": "Bae-Hyunji-Jane", "name": { "family": "Bae", "given": "H. J." }, "orcid": "0000-0001-6789-6209" }, { "id": "de-Luca-L", "name": { "family": "de Luca", "given": "L." } } ] }, "title": "A low-cost time-advancing strategy for energy-preserving turbulent simulations", "ispublished": "unpub", "full_text_status": "public", "note": "The authors would like to thank Prof. Parviz Moin for fruitful discussions during the\nSummer Program. The authors acknowledge utilization of the Certainty cluster awarded\nby the National Science Foundation to CTR.\n\nPublished - CTR2014-1.pdf
", "abstract": "Energy-conserving discretizations are widely regarded as a fundamental requirement\nfor high-fidelity simulations of turbulent flows. The skew-symmetric splitting of the non-\nlinear term is a well-known approach to obtain semi-discrete conservation of energy in\nthe inviscid limit. However, its computation is roughly twice as expensive as that of the\ndivergence or advective forms alone. A novel time-advancement strategy that retains the\nconservation properties of skew-symmetric-based schemes at a reduced computational\ncost has been developed. This method is based on properly constructed Runge-Kutta\nschemes in which a different form (advective or divergence) for the convective term is\nadopted at each stage. A general framework is presented to derive schemes with prescribed accuracy on both solution and energy conservation. Simulations of homogeneous\nisotropic turbulence show that, on equal results, the new procedure can be considerably\nfaster than skew-symmetric-based techniques.", "date": "2014-12", "date_type": "published", "publisher": "Stanford University", "id_number": "CaltechAUTHORS:20210325-145350953", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210325-145350953", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "primary_object": { "basename": "CTR2014-1.pdf", "url": "https://authors.library.caltech.edu/records/fbeny-5mv56/files/CTR2014-1.pdf" }, "pub_year": "2014", "author_list": "Capuano, F.; Coppola, G.; et el." }, { "id": "https://authors.library.caltech.edu/records/63rn3-sht84", "eprint_id": 72980, "eprint_status": "archive", "datestamp": "2023-08-20 03:52:37", "lastmod": "2023-10-24 14:53:00", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Paranjape-A-A", "name": { "family": "Paranjape", "given": "Aditya A." }, "orcid": "0000-0002-3164-3215" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Dyadic perturbation observer framework for control of a class of nonlinear PDE/ODE systems", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2014 IEEE. \n\nDate Added to IEEE Xplore: 12 February 2015. \n\nThis research was supported by NSF (IIS-1253758) and ARO (W911NF-10-1-0296). \n\nWe gratefully acknowledge the inspiration and the encouragement from Prof. Miroslav Krstic. We thank the anonymous reviewers for the meticulous and thorough comments which helped improve the paper to its current form.", "abstract": "This paper presents the general theory of the dyadic perturbation observer framework as a generic method for controlling a class of nonlinear systems described by partial and/or ordinary differential equations. The method is particularly applicable to boundary control problems for systems described by partial differential equations. Conditions for closed-loop stability and robustness are derived using finite-gain L stability theory, and the results are further specialized for finite dimensional systems.", "date": "2014-12", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "2065-2070", "id_number": "CaltechAUTHORS:20161220-110956591", "isbn": "978-1-4673-6090-6", "book_title": "53rd IEEE Conference on Decision and Control", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161220-110956591", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "IIS-1253758" }, { "agency": "Army Research Office (ARO)", "grant_number": "W911NF-10-1-0296" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/CDC.2014.7039702", "pub_year": "2014", "author_list": "Paranjape, Aditya A. and Chung, Soon-Jo" }, { "id": "https://authors.library.caltech.edu/records/dds0a-cgz43", "eprint_id": 108566, "eprint_status": "archive", "datestamp": "2023-08-20 03:55:58", "lastmod": "2023-10-23 17:08:53", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Verstappen-Roel", "name": { "family": "Verstappen", "given": "R. W. C. P." }, "orcid": "0000-0001-8565-6188" }, { "id": "Rozema-Wybe", "name": { "family": "Rozema", "given": "W." } }, { "id": "Bae-Hyunji-Jane", "name": { "family": "Bae", "given": "H. J." }, "orcid": "0000-0001-6789-6209" } ] }, "title": "Numerical scale separation in large-eddy simulation", "ispublished": "unpub", "full_text_status": "public", "note": "The authors kindly acknowledge Guillaume Balarac and Antoine Vollant for performing\nspectral simulations with the qr model during the Summer Program.\n\nPublished - 06_verstappen.pdf
", "abstract": "Large-eddy simulation (LES) seeks to predict the dynamics of spatially filtered turbulent flows. The essence of a scale-separation LES model is that it stops the nonlinear\nproduction of smaller scales of motion at the scale set by the filter: there the modeled\neddy dissipation has to balance the production. Numerical discretization changes both\nthe nonlinear production and dissipation of sub-filter scales. Therefore, the discrete balance between production and dissipation can deviate from the continuous balance, in\nparticular if a balance is imposed near the scale set by the numerical grid. This paper\ndemonstrates that a scale-separation LES model should attain a production-dissipation\nbalance in the numerical setting. Eddy-viscosity models based on this requirement are\nderived and successfully applied in simulations of decaying isotropic turbulence and channel flow.", "date": "2014-12", "date_type": "published", "publisher": "Stanford University", "id_number": "CaltechAUTHORS:20210326-095748691", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210326-095748691", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "primary_object": { "basename": "06_verstappen.pdf", "url": "https://authors.library.caltech.edu/records/dds0a-cgz43/files/06_verstappen.pdf" }, "pub_year": "2014", "author_list": "Verstappen, R. W. C. P.; Rozema, W.; et el." }, { "id": "https://authors.library.caltech.edu/records/44295-2n136", "eprint_id": 51796, "eprint_status": "archive", "datestamp": "2023-08-19 17:25:49", "lastmod": "2023-10-18 17:10:37", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Roshko-A", "name": { "family": "Roshko", "given": "Anatol" } } ] }, "title": "Structure and Mixing in Turbulent Shear Flows", "ispublished": "unpub", "full_text_status": "public", "note": "ONR Contract No. N00014-76-C-0260 Task No. NR 062, 431", "abstract": "The broad problem being addressed in our research is to identify and describe the primary vortical (\"coherent\", \"organized\") large structures in various turbulent shear flows; to determine how they contribute to the\nmixing processes; and to make use of them in modelling and in possibly controlling or modifying those flows. Accumulating experimental evidence suggests that these primary vortical structures are different in different\nshear flows. Conclusions which follow from these views are that (i) there cannot be a universal turbulence model for these different flows; and (ii) existence of such structures implies the possibility of their manipulation\nor control and thus modification of the flow itself. These organized structures (and their response to excitation) are manifestations of instability response to natural or imposed disturbances and thus may be important\nin cooperation with other, physical processes, e.g. , acoustic coupling, rate controlled chemistry, etc., in problems like combustion chamber instability.", "date": "2014-11-15", "date_type": "published", "publisher": "California Institute of Technology", "id_number": "CaltechAUTHORS:20141114-143226217", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141114-143226217", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-76-C-0260" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "primary_object": { "basename": "roshko.pdf", "url": "https://authors.library.caltech.edu/records/44295-2n136/files/roshko.pdf" }, "pub_year": "2014", "author_list": "Roshko, Anatol" }, { "id": "https://authors.library.caltech.edu/records/j3e5y-9rj36", "eprint_id": 51800, "eprint_status": "archive", "datestamp": "2023-08-19 17:25:58", "lastmod": "2023-10-18 17:10:46", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Culick-F-E-C", "name": { "family": "Culick", "given": "F. E. C." } }, { "id": "Marble-F-E", "name": { "family": "Marble", "given": "Frank E." } }, { "id": "Zukoski-E-E", "name": { "family": "Zukoski", "given": "E. E." } } ] }, "title": "Research on Mechanisms of Exciting Pressure Oscillations in Ramjet Engines", "ispublished": "unpub", "full_text_status": "public", "note": "AFOSR Grant Number: AFOSR-84-0286", "abstract": "An analytical and experimental study is being made of the role of combustion in large vortical structures in the mechanism of unsteady and unstable burning in air-breathing engines. A large body of experimental evidence supports the contention that these periodic fluctuations are themselves generated by the nonsteady flow over the flame holders and other surfaces. The mechanism itself is relatively independent of the acoustic configuration of the\npowerplant and its installation and hence constitutes the\nfundamental element of the combustion instability process. Whether or not the mechanism is excited does, however, depend upon the detailed acoustic properties of the combustion chamber and its environment and in many circumstances it is apparent that non-linear\nacoustics plays an essential role. As a consequence, the program includes detailed analytical studies of linear and non-linear acoustics in combustion configurations as a means of coupling the instability mechanism to a particular environment. The effective separation of the instability process into i) its mechanism and ii)\nits environment is aimed at eventually providing means of rational scaling of laboratory size experiments.", "date": "2014-11-15", "date_type": "published", "publisher": "California Institute of Technology", "id_number": "CaltechAUTHORS:20141114-143821228", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141114-143821228", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force of Scientific Research (AFOSR)", "grant_number": "AFOSR-84-0286" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "primary_object": { "basename": "culick.pdf", "url": "https://authors.library.caltech.edu/records/j3e5y-9rj36/files/culick.pdf" }, "pub_year": "2014", "author_list": "Culick, F. E. C.; Marble, Frank E.; et el." }, { "id": "https://authors.library.caltech.edu/records/zx7z1-bf968", "eprint_id": 51799, "eprint_status": "archive", "datestamp": "2023-08-19 17:25:53", "lastmod": "2023-10-18 17:10:44", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Liepmann-H-W", "name": { "family": "Liepmann", "given": "H. W." } }, { "id": "Broadwell-J-E", "name": { "family": "Broadwell", "given": "J. E." } }, { "id": "Dimotakis-P-E", "name": { "family": "Dimotakis", "given": "P. E." } } ] }, "title": "Chemical Reactions in Turbulent Mixing Flows", "ispublished": "unpub", "full_text_status": "public", "note": "AFOSR Grant 83-0213", "abstract": "This is a continuing effort in both gas phase and liquid phase mixing, chemical reactions and combustion, in moderate to high Reynolds number turbulent free shear flows. This is primarily an experimental investigation closely supported by theoretical and modeling efforts, as well as specific diagnostics developments, as dictated by specific needs of the experimental program.", "date": "2014-11-15", "date_type": "published", "publisher": "California Institute of Technology", "id_number": "CaltechAUTHORS:20141114-143811731", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141114-143811731", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force of Scientific Research (AFOSR)", "grant_number": "83-0213" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "primary_object": { "basename": "liepmann.pdf", "url": "https://authors.library.caltech.edu/records/zx7z1-bf968/files/liepmann.pdf" }, "pub_year": "2014", "author_list": "Liepmann, H. W.; Broadwell, J. E.; et el." }, { "id": "https://authors.library.caltech.edu/records/fewdn-93s06", "eprint_id": 73333, "eprint_status": "archive", "datestamp": "2023-08-20 03:12:16", "lastmod": "2023-10-24 15:14:03", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bandyopadhyay-S", "name": { "family": "Bandyopadhyay", "given": "Saptarshi" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Hadaegh-F-Y", "name": { "family": "Hadaegh", "given": "Fred Y." } } ] }, "title": "Probabilistic swarm guidance using optimal transport", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2014 IEEE. \n\nThis research was supported in part by AFOSR grant FA95501210193 and the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.", "abstract": "Probabilistic swarm guidance enables autonomous agents to generate their individual trajectories independently so that the entire swarm converges to the desired distribution shape. In contrast with previous homogeneous or inhomogeneous Markov chain based approaches [1], this paper presents an optimal transport based approach which guarantees faster convergence, minimizes a given cost function, and reduces the number of transitions for achieving the desired formation. Each agent first estimates the current swarm distribution by communicating with neighboring agents and using a consensus algorithm and then solves the optimal transport problem, which is recast as a linear program, to determine its transition probabilities. We discuss methods for handling motion constraints and also demonstrate the superior performance of the proposed algorithm by numerically comparing it with existing Markov chain based strategies.", "date": "2014-10", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "498-505", "id_number": "CaltechAUTHORS:20170109-103702672", "isbn": "978-1-4799-7409-2", "book_title": "2014 IEEE Conference on Control Applications (CCA)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170109-103702672", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA95501210193" }, { "agency": "NASA/JPL/Caltech" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/CCA.2014.6981395", "pub_year": "2014", "author_list": "Bandyopadhyay, Saptarshi; Chung, Soon-Jo; et el." }, { "id": "https://authors.library.caltech.edu/records/760cp-p5640", "eprint_id": 98820, "eprint_status": "archive", "datestamp": "2023-08-20 03:13:15", "lastmod": "2023-10-18 17:39:49", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Underwood-C", "name": { "family": "Underwood", "given": "Craig" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" }, { "id": "Lappas-V-J", "name": { "family": "Lappas", "given": "Vaios J." } }, { "id": "Bridges-C-P", "name": { "family": "Bridges", "given": "Christopher P." } }, { "id": "Baker-J", "name": { "family": "Baker", "given": "John" } } ] }, "title": "Using CubeSat/Micro-Satellite Technology to Demonstrate the Autonomous Assembly of a Reconfigurable Space Telescope (AAReST)", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2014 IAF. \n\n21st IAA Symposium on Small Satellite Missions. \n\nPaper number: IAC-14,B4,2,4,x25987.\n\nPublished - IAC-14,B4,2,4,x25987.brief.pdf
", "abstract": "Future space telescopes with diameter over 20 m will require new approaches: either high-precision formation flying or in-orbit assembly. We believe the latter holds promise as a potentially lower cost and more practical solution in the near term, provided much of the assembly can be carried out autonomously. To gain experience, and to provide risk reduction, we propose a combined mico/nano-satellite demonstration mission that will focus on the required optical technology (adaptive mirrors, phase-sensitive detectors) and autonomous rendezvous and docking technology (inter-satellite links, relative position sensing, automated docking mechanisms). The mission will involve two \"3U\" Cubesat-like nanosatellites (\"MirrorSats\") each carrying an electrically actuated adaptive mirror, and each capable of autonomous un-docking and re-docking with a small central \"15U\" class micro/nano-satellite core, which houses two fixed mirrors and a boom-deployed focal plane assembly. All three spacecraft will be launched as a single ~40kg micro-satellite package.\nThe spacecraft busses are based on heritage from Surrey's SNAP-1 and STRaND-1 missions (launched in 2000 and 2013 respectively), whilst the optics, imaging sensors and shape adjusting adaptive mirrors (with their associated adjustment mechanisms) are provided by CalTech/JPL. The spacecraft busses provide precise orbit and attitude control, with inter-satellite links and optical navigation to mediate the docking process. The docking system itself is based on the electromagnetic docking system being developed at the Surrey Space Centre (SSC), together with rendezvous sensing technology developed for STRaND-2. On orbit, the mission profile will firstly establish the imaging capability of the compound spacecraft before undocking, and then autonomously re-docking a single MirrorSat. This will test the docking system, autonomous navigation and system identification technology. If successful, the next stage will see the two MirrorSat spacecraft undock and re-dock to the core spacecraft in a linear formation to represent a large (but sparse) aperture for high resolution imaging. The imaging of stars is the primary objective, but other celestial and terrestrial targets are being considered. Teams at CalTech and SSC are currently working on the mission planning and development of space hardware. The autonomous rendezvous and docking system is currently under test on a 2D air-bearing table at SSC, and the propulsion and precision attitude control system is currently in development. Launch is planned for 2015. This paper details the mission concept, technology involved and progress to date.", "date": "2014-10", "date_type": "published", "publisher": "International Astronautical Federation", "id_number": "CaltechAUTHORS:20190924-081804330", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190924-081804330", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "primary_object": { "basename": "IAC-14,B4,2,4,x25987.brief.pdf", "url": "https://authors.library.caltech.edu/records/760cp-p5640/files/IAC-14,B4,2,4,x25987.brief.pdf" }, "pub_year": "2014", "author_list": "Underwood, Craig; Pellegrino, Sergio; et el." }, { "id": "https://authors.library.caltech.edu/records/pey0f-vmq79", "eprint_id": 55425, "eprint_status": "archive", "datestamp": "2023-08-22 13:37:33", "lastmod": "2023-10-20 22:14:04", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Karanjgaokar-N", "name": { "family": "Karanjgaokar", "given": "Nikhil" } }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "Guruswami" }, "orcid": "0000-0002-2912-0001" } ] }, "title": "Experimental Inference of Inter-Particle Forces in Granular Systems Using Digital Image Correlation", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Digital image correlation; Granular materials; Granular element method; Impact testing; Force chains", "note": "\u00a9 2015 The Society for Experimental Mechanics, Inc.", "abstract": "The observed features of granular materials can be successfully predicted using models based on relationship of inter-particle forces and macroscopic properties. In the current work, a drop-tower experimental setup was developed for the impact testing of 2D assembly of cylinders and 3D assembly of spheres with impactor velocity of around 6 m/s. This drop tower setup was used to load 2D granular assembly of polyurethane and polycarbonate cylinders of 1.25\u2033 length with 3 different diameters of 1/4\u2033, 3/8\u2033 and 1/2\u2033. A high speed camera was used for recording the images of approx. 800\u2009\u00d7\u2009800 resolution at speeds between 10,000 and 15,000 fps to monitor the deformation of the cylinders. The recorded images were used to obtain the granular fabric and kinematics for each grain and average strains were obtained from images using digital image correlation. The experimental data was subsequently used to infer the interparticle forces between individual grains in the assembly using a Granular Element Method based optimization process.", "date": "2014-09-08", "date_type": "published", "publisher": "Springer", "place_of_pub": "Cham, Switzerland", "pagerange": "379-385", "id_number": "CaltechAUTHORS:20150302-135724738", "isbn": "978-3-319-06985-2", "book_title": "Advancement of Optical Methods in Experimental Mechanics", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150302-135724738", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Jin-H", "name": { "family": "Jin", "given": "Helena" } }, { "id": "Sciammarella-C", "name": { "family": "Sciammarella", "given": "Cesar" } }, { "id": "Yoshida-S", "name": { "family": "Yoshida", "given": "Sanichiro" } }, { "id": "Lamberti-L", "name": { "family": "Lamberti", "given": "Luciano" } } ] }, "doi": "10.1007/978-3-319-06986-9_45", "pub_year": "2014", "author_list": "Karanjgaokar, Nikhil and Ravichandran, Guruswami" }, { "id": "https://authors.library.caltech.edu/records/ftbf3-jrr57", "eprint_id": 73158, "eprint_status": "archive", "datestamp": "2023-08-20 02:48:16", "lastmod": "2023-10-24 15:05:07", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Morgan-Daniel", "name": { "family": "Morgan", "given": "Daniel" } }, { "id": "Subramanian-G-P", "name": { "family": "Subramanian", "given": "Giri Prashanth" } }, { "id": "Bandyopadhyay-S", "name": { "family": "Bandyopadhyay", "given": "Saptarshi" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Hadaegh-F-Y", "name": { "family": "Hadaegh", "given": "Fred Y." } } ] }, "title": "Probabilistic guidance of distributed systems using sequential convex programming", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2014 IEEE. \n\nDate Added to IEEE Xplore: 06 November 2014. \n\nThis research was supported in part by AFOSR grant FA95501210193 and a NASA Space Technology Research Fellowship (NNX11AM84H). This research was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. \n\n\u00a9 2014 California Institute of Technology. Government sponsorship acknowledged.\n\nPublished - PSG_MPC_final.pdf
", "abstract": "In this paper, we integrate, implement, and validate formation flying algorithms for a large number of agents using probabilistic guidance of distributed systems with inhomogeneous Markov chains and model predictive control with sequential convex programming. Using an inhomogeneous Markov chain, each agent determines its target position during each iteration in a statistically independent manner while the distributed system converges to the desired formation. Moreover, the distributed system is robust to external disturbances or damages to the formation. Once the target positions are assigned, an optimal control problem is formulated to ensure that the agents reach the target positions while avoiding collisions. This problem is solved using sequential convex programming to determine optimal, collision-free trajectories and model predictive control is implemented to update these trajectories as new state information becomes available. Finally, we validate the probabilistic guidance of distributed systems and model predictive control algorithms using the formation flying testbed.", "date": "2014-09", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "3850-3857", "id_number": "CaltechAUTHORS:20161222-115746072", "isbn": "978-1-4799-6934-0", "book_title": "2014 IEEE/RSJ International Conference on Intelligent Robots and Systems", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161222-115746072", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA95501210193" }, { "agency": "NASA", "grant_number": "NNX11AM84H" }, { "agency": "NASA/JPL/Caltech" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/IROS.2014.6943103", "primary_object": { "basename": "PSG_MPC_final.pdf", "url": "https://authors.library.caltech.edu/records/ftbf3-jrr57/files/PSG_MPC_final.pdf" }, "pub_year": "2014", "author_list": "Morgan, Daniel; Subramanian, Giri Prashanth; et el." }, { "id": "https://authors.library.caltech.edu/records/9rjx7-nmn67", "eprint_id": 87982, "eprint_status": "archive", "datestamp": "2023-08-20 02:24:17", "lastmod": "2024-01-14 20:28:16", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Arenberg-Jonathan", "name": { "family": "Arenberg", "given": "Jonathan" } }, { "id": "Atkinson-Charles", "name": { "family": "Atkinson", "given": "Charles" } }, { "id": "Breckinridge-James-B", "name": { "family": "Breckinridge", "given": "Jim" }, "orcid": "0000-0002-9488-098X" }, { "id": "Conti-Alberto", "name": { "family": "Conti", "given": "Alberto" } }, { "id": "Feinberg-Lee", "name": { "family": "Feinberg", "given": "Lee" } }, { "id": "Lillie-Charles-F", "name": { "family": "Lillie", "given": "Charles" } }, { "id": "MacEwen-Howard-A", "name": { "family": "MacEwen", "given": "Howard A." } }, { "id": "Polidan-Ronald-S", "name": { "family": "Polidan", "given": "Ronald" } }, { "id": "Postman-Marc", "name": { "family": "Postman", "given": "Marc" }, "orcid": "0000-0002-9365-7989" }, { "id": "Matthews-Gary", "name": { "family": "Matthews", "given": "Gary" } }, { "id": "Smith-Eric", "name": { "family": "Smith", "given": "Eric" } } ] }, "title": "A new paradigm for space astrophysics mission design", "ispublished": "unpub", "full_text_status": "public", "keywords": "Space Mission Design, Cost Scaling, Standardization", "note": "\u00a9 2014 Society of Photo-Optical Instrumentation Engineers (SPIE).\n\nPublished - 914315.pdf
", "abstract": "Pursuing ground breaking science in a highly cost-constrained environment presents new challenges to the development of future space astrophysics missions. Within the conventional cost models for large observatories, executing a flagship \"mission after next\" appears to be unstainable. To achieve our nation's science ambitions requires a new paradigm of system design, development and manufacture. This paper explores the nature of the current paradigm and proposes a series of steps to guide the entire community to a sustainable future.", "date": "2014-08-02", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "Art. no. 914315", "id_number": "CaltechAUTHORS:20180718-161634414", "isbn": "9780819496119", "book_title": "Space Telescopes and Instrumentation 2014: Optical, Infrared, and Millimeter Wave", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180718-161634414", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Oschmann-Jacobus-M", "name": { "family": "Oschmann", "given": "Jacobus M." } }, { "id": "Clampin-Mark-C", "name": { "family": "Clampin", "given": "Mark" } }, { "id": "Fazio-Giovanni-G", "name": { "family": "Fazio", "given": "Giovanni G." } }, { "id": "MacEwen-Howard-A", "name": { "family": "MacEwen", "given": "Howard A." } } ] }, "doi": "10.1117/12.2055509", "primary_object": { "basename": "914315.pdf", "url": "https://authors.library.caltech.edu/records/9rjx7-nmn67/files/914315.pdf" }, "pub_year": "2014", "author_list": "Arenberg, Jonathan; Atkinson, Charles; et el." }, { "id": "https://authors.library.caltech.edu/records/5rkkq-14x14", "eprint_id": 87981, "eprint_status": "archive", "datestamp": "2023-08-20 02:24:13", "lastmod": "2024-01-14 20:28:14", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Polidan-Ronald-S", "name": { "family": "Polidan", "given": "Ronald S." } }, { "id": "Breckinridge-James-B", "name": { "family": "Breckinridge", "given": "James B." }, "orcid": "0000-0002-9488-098X" }, { "id": "Lillie-Charles-F", "name": { "family": "Lillie", "given": "Charles F." } }, { "id": "MacEwen-Howard-A", "name": { "family": "MacEwen", "given": "Howard A." } }, { "id": "Flannery-Martin-R", "name": { "family": "Flannery", "given": "Martin R." } }, { "id": "Dailey-Dean-R", "name": { "family": "Dailey", "given": "Dean R." } } ] }, "title": "An evolvable space telescope for future astronomical missions", "ispublished": "unpub", "full_text_status": "public", "keywords": "Space telescope, segmented telescopes, in-space assembly and servicing", "note": "\u00a9 2014 Society of Photo-Optical Instrumentation Engineers (SPIE). \n\nThe authors would like to acknowledge strong support and internal funding from Northrop Grumman Aerospace Systems and very helpful comments, suggestions, and criticisms from a variety of people, including Jonathan Arenberg, Alberto Conti, Lee Feinberg, Marc Postman, Theodore Swanson, and Harley Thronson.\n\nPublished - 914319.pdf
", "abstract": "Astronomical flagship missions after JWST will require affordable space telescopes and science instruments. Innovative spacecraft-electro-opto-mechanical system architectures matched to the science requirements are needed for observations for exoplanet characterization, cosmology, dark energy, galactic evolution formation of stars and planets, and many other research areas. The needs and requirements to perform this science will continue to drive us toward larger and larger apertures. Recent technology developments in precision station keeping of spacecraft, interplanetary transfer orbits, wavefront/sensing and control, laser engineering, macroscopic application of nano-technology, lossless optical designs, deployed structures, thermal management, interferometry, detectors and signal processing enable innovative telescope/system architectures with break-through performance. Unfortunately, NASA's budget for Astrophysics is unlikely to be able to support the funding required for the 8 m to 16 m telescopes that have been studied as a follow-on to JWST using similar development/assembly approaches without decimating the rest of the Astrophysics Division's budget. Consequently, we have been examining the feasibility of developing an \"Evolvable Space Telescope\" that would begin as a 3 to 4 m telescope when placed on orbit and then periodically be augmented with additional mirror segments, structures, and newer instruments to evolve the telescope and achieve the performance of a 16 m or larger space telescope. This paper reviews the approach for such a mission and identifies and discusses candidate architectures.", "date": "2014-08-02", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "Art. no. 914319", "id_number": "CaltechAUTHORS:20180718-160040918", "isbn": "9780819496119", "book_title": "Space Telescopes and Instrumentation 2014: Optical, Infrared, and Millimeter Wave", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180718-160040918", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Northrop Grumman Corporation" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Oschmann-Jacobus-M", "name": { "family": "Oschmann", "given": "Jacobus M." } }, { "id": "Clampin-Mark-C", "name": { "family": "Clampin", "given": "Mark" } }, { "id": "Fazio-Giovanni-G", "name": { "family": "Fazio", "given": "Giovanni G." } }, { "id": "MacEwen-Howard-A", "name": { "family": "MacEwen", "given": "Howard A." } } ] }, "doi": "10.1117/12.2057161", "primary_object": { "basename": "914319.pdf", "url": "https://authors.library.caltech.edu/records/5rkkq-14x14/files/914319.pdf" }, "pub_year": "2014", "author_list": "Polidan, Ronald S.; Breckinridge, James B.; et el." }, { "id": "https://authors.library.caltech.edu/records/yc0m9-3j140", "eprint_id": 97888, "eprint_status": "archive", "datestamp": "2023-08-20 02:22:49", "lastmod": "2023-10-18 16:50:57", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lee-Nicolas", "name": { "family": "Lee", "given": "Nicolas" }, "orcid": "0000-0001-5500-1324" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Packaging and deployment strategies for synthetic aperture radar membrane antenna arrays", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2014 IEEE. \n\nN. Lee was supported by a postdoctoral fellowship from the W. M. Keck Institute for Space Studies.", "abstract": "The performance of spaceborne synthetic aperture radar (SAR) is limited by the size and therefore the areal density of the antenna array. Conventional arrays consist of radiating elements mounted on hinged panels that are relatively heavy. In order to produce larger arrays capable of operating at higher altitudes, or to support comparable SAR payloads on smaller spacecraft, a lighter structure such as one using membranes must be used. Membrane antenna arrays have been developed, but deployment remains a challenge. This paper describes possible techniques to package and deploy membrane structures that can support these antenna arrays.", "date": "2014-08", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "1-4", "id_number": "CaltechAUTHORS:20190814-104606776", "isbn": "9781467352253", "book_title": "2014 XXXIth URSI General Assembly and Scientific Symposium (URSI GASS)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190814-104606776", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Keck Institute for Space Studies (KISS)" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Keck-Institute-for-Space-Studies" } ] }, "doi": "10.1109/ursigass.2014.6929611", "pub_year": "2014", "author_list": "Lee, Nicolas and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/q1k24-tgt76", "eprint_id": 58285, "eprint_status": "archive", "datestamp": "2023-08-20 02:01:02", "lastmod": "2024-01-13 16:22:26", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Steeves-J", "name": { "family": "Steeves", "given": "John" } }, { "id": "Laslandes-M", "name": { "family": "Laslandes", "given": "Marie" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" }, { "id": "Redding-D", "name": { "family": "Redding", "given": "David" } }, { "id": "Bradford-S-C", "name": { "family": "Bradford", "given": "Samuel Case" } }, { "id": "Wallace-J-K", "name": { "family": "Wallace", "given": "James Kent" } }, { "id": "Barbee-T", "name": { "family": "Barbee", "given": "Troy" } } ] }, "title": "Design, fabrication and testing of active carbon shell mirrors for space telescope applications", "ispublished": "unpub", "full_text_status": "public", "keywords": "Active Mirrors, Space Telescopes, CFRP, Nanolaminate, Replication, Metrology", "note": "\u00a9 2014 Society of Photo-Optical Instrumentation Engineers (SPIE). Published date July 28, 2014. \n\nWe thank Keith Patterson, Andrew Shapiro and Scott Basinger ( NASA JPL) for their technical and programmatic support throughout t.he project. Financial support from the Natural Sciences and Engineering Research Council (NSERC) of Canada is gratefully acknowledged. A part of this research was carried out at the Jet. Propulsion Laboratory, California Institute of Technology under a contract With the National Aeronautics and Space Administration (NASA).\n\nPublished - Steeves_2014p915105.pdf
", "abstract": "A novel active mirror concept based on carbon fiber reinforced polymer (CFRP) materials is presented. A nanolaminate facesheet, active piezoelectric layer and printed electronics are implemented in order to provide the reflective surface, actuation capabilities and electrical wiring for the mirror. Mirrors of this design are extremely thin (500-850 \u00b5m), lightweight (~ 2 kg/m^2) and have large actuation capabilities (~ 100 \u00b5m peak- to-valley deformation per channel). Replication techniques along with simple bonding/transferring processes are implemented eliminating the need for grinding and polishing steps. An outline of the overall design, component materials and fabrication processes is presented. A method to size the active layer for a given mirror design, along with simulation predictions on the correction capabilities of the mirror are also outlined. A custom metrology system used to capture the highly deformable nature of the mirrors is demonstrated along with preliminary prototype measurements.", "date": "2014-07-28", "date_type": "published", "publisher": "Society of Photo-Optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "Art. No. 915105", "id_number": "CaltechAUTHORS:20150616-134615567", "isbn": "978-0-8194-9619-5", "book_title": "Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150616-134615567", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Natural Sciences and Engineering Research Council of Canada (NSERC)" }, { "agency": "NASA/JPL/Caltech" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Navarro-R", "name": { "family": "Navarro", "given": "Ram\u03ccn" } }, { "id": "Cunningham-C-R", "name": { "family": "Cunningham", "given": "Colin R." } }, { "id": "Barto-A-A", "name": { "family": "Barto", "given": "Allison A." } } ] }, "doi": "10.1117/12.2056560", "primary_object": { "basename": "Steeves_2014p915105.pdf", "url": "https://authors.library.caltech.edu/records/q1k24-tgt76/files/Steeves_2014p915105.pdf" }, "pub_year": "2014", "author_list": "Steeves, John; Laslandes, Marie; et el." }, { "id": "https://authors.library.caltech.edu/records/cyt65-8xc31", "eprint_id": 61058, "eprint_status": "archive", "datestamp": "2023-08-20 01:55:22", "lastmod": "2024-01-13 16:26:02", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Laslandes-M", "name": { "family": "Laslandes", "given": "Marie" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" }, { "id": "Steeves-J-B", "name": { "family": "Steeves", "given": "John" } }, { "id": "Patterson-K", "name": { "family": "Patterson", "given": "Keith" } } ] }, "title": "Optimization of Electrode Configuration in Surface-Parallel Actuated Deformable Mirrors", "ispublished": "unpub", "full_text_status": "public", "keywords": "Deformable Mirror - Active Optics - Telescope - Optimization - Bimorph Mirror", "note": "\u00a9 2014 SPIE.\n\nWe thank Xin Ning (Caltech) for help with the optimization algorithm. ML acknowledges the support of a postdoctoral grant from the French Defense procurement agency (DGA) held through Aix-Marseille University, France. Financial support from the Keck Institute of Space Studies and the Dow Resnick Bridge program at Caltech is gratefully acknowledged. A part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with National Aeronautics and Space Administration (NASA).\n\nPublished - Laslandes_2014p914843.pdf
", "abstract": "Thin, lightweight and low-cost deformable mirrors have been recently proposed, providing a pertinent device for wavefront error correction. We present different approaches to optimize actuator arrangement. The design is optimized according to a given correction requirement, through the number of electrodes, their shape and location. A first method focuses on the compensation of a given optical aberration (astigmatism). A second method directly optimizes the correction of a set of optical modes, taking into account the voltage limitation. We will describe the optimization techniques and give some examples of applications and design performance.", "date": "2014-07-21", "date_type": "published", "publisher": "Society of Photo-Optical Instrumentation Engineers", "place_of_pub": "Bellingham, WA", "pagerange": "Art. No. 914843", "id_number": "CaltechAUTHORS:20151013-130020372", "isbn": "978-0-8194-9616-4", "book_title": "Adaptive optics systems IV", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151013-130020372", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Direction g\u00e9n\u00e9rale de l'armement (DGA)" }, { "agency": "Keck Institute for Space Studies (KISS)" }, { "agency": "Dow Resnick Bridge Program" }, { "agency": "NASA/JPL/Caltech" } ] }, "local_group": { "items": [ { "id": "Keck-Institute-for-Space-Studies" }, { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Marchetti-E", "name": { "family": "Marchetti", "given": "Enrico" } }, { "id": "Close-L-M", "name": { "family": "Close", "given": "Laird M." } }, { "id": "V\u00e9ran-J-P", "name": { "family": "V\u00e9ran", "given": "Jean-Pierre" } } ] }, "doi": "10.1117/12.2056495", "primary_object": { "basename": "Laslandes_2014p914843.pdf", "url": "https://authors.library.caltech.edu/records/cyt65-8xc31/files/Laslandes_2014p914843.pdf" }, "pub_year": "2014", "author_list": "Laslandes, Marie; Pellegrino, Sergio; et el." }, { "id": "https://authors.library.caltech.edu/records/0qq3f-88822", "eprint_id": 72491, "eprint_status": "archive", "datestamp": "2023-08-22 13:09:45", "lastmod": "2023-10-23 22:39:35", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kulkarni-V-V", "name": { "family": "Kulkarni", "given": "Vishwesh V." } }, { "id": "Paranjape-A-A", "name": { "family": "Paranjape", "given": "Aditya A." }, "orcid": "0000-0002-3164-3215" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Robust Tunable Transcriptional Oscillators Using Dynamic Inversion", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Transcriptional network; Elowitz-Leibler; Dynamic inversion; Adaptive control; \u21121 adaptive control; mRNA; Protein; Tracking controller; Stability; Zames-Falb multiplier", "note": "\u00a9 2014 Springer Science+Business Media Dordrecht. \n\nWe thank Prof. Michael Elowitz (California Institute of Technology) for clarifying our doubts on the ODE model of the EL repressilator. This research is supported, in part, by the NSF CAREER Award 0845650, NSF BIO Computing, NSF Computing and Communications Foundationsx, and the U.S. Army Research Office Award W911NF-10-1-0296. Competing Interests: There are none. Author's Contributions: VVK derived Lemmae 1 and 2, and Theorems 3 and 4. VVK, AAP, and SJC synthesized the dynamic inversion control. AAP simulated the closed loop system using MATLAB.", "abstract": "We present a theory and associated algorithms to synthesize controllers that may be used to build robust tunable oscillations in biological networks. As an illustration, we build robust tunable oscillations in the celebrated repressilator synthesized by Elowitz and Leibler. The desired oscillations in a set of mRNA's and proteins are obtained by injecting an oscillatory input as a reference and by synthesizing a dynamic inversion based tracking controller. This approach ensures that the repressilator can exhibit oscillations irrespective of (1) the maximum number of proteins per cell and (2) the ratio of the protein lifetimes to the mRNA lifetimes. The frequency and the amplitude of at least one output (either mRNA or protein) can now be controlled arbitrarily. In addition, we characterize the L_2 gain stability of this 3-node network and generalize it to the case of N-node networks.", "date": "2014-07-04", "date_type": "published", "publisher": "Springer Netherlands", "place_of_pub": "Berlin", "pagerange": "103-119", "id_number": "CaltechAUTHORS:20161201-103533605", "isbn": "978-94-017-9040-6", "book_title": "A Systems Theoretic Approach to Systems and Synthetic Biology I: Models and System Characterizations", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161201-103533605", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "CCF-0845650" }, { "agency": "Army Research Office (ARO)", "grant_number": "W911NF-10-1-0296" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Kulkarni-V-V", "name": { "family": "Kulkarni", "given": "Vishwesh V." } }, { "id": "Stan-G-B", "name": { "family": "Stan", "given": "Guy-Bart" } }, { "id": "Raman-K", "name": { "family": "Raman", "given": "Karthik" } } ] }, "doi": "10.1007/978-94-017-9041-3_4", "pub_year": "2014", "author_list": "Kulkarni, Vishwesh V.; Paranjape, Aditya A.; et el." }, { "id": "https://authors.library.caltech.edu/records/5zk67-wse09", "eprint_id": 97985, "eprint_status": "archive", "datestamp": "2023-08-20 01:28:03", "lastmod": "2023-10-18 16:56:23", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kartha-A", "name": { "family": "Kartha", "given": "Anand" } }, { "id": "Subbareddy-P-K", "name": { "family": "Subbareddy", "given": "Pramod K." } }, { "id": "Candler-G-V", "name": { "family": "Candler", "given": "Graham V." } }, { "id": "Dimotakis-P-E", "name": { "family": "Dimotakis", "given": "Paul E." } } ] }, "title": "Large-Eddy Simulation of Supersonic Reacting Mixing Layers", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2014 American Institute of Aeronautics and Astronautics.", "abstract": "We study a class of chemically reacting, spatially evolving, supersonic mixing layers via large eddy simulation. Specifically, the goal is to reproduce the experimental results on molecular mixing and heat release performed at Caltech by Bonanos et al. Here, the mixing layer is formed as a result of the interaction of supersonic and subsonic streams: the supersonic stream expands over a 30\u00b0 perforated ramp and interacts with a subsonic stream of fluid injected into the combustor through the ramp. The primary (top, supersonic) stream contains a small amount of H_2 as the fuel. The secondary stream (injected through the ramp) contains a fractional amount of F_2 which acts as the oxidizer. The hypergolic reaction between hydrogen and fluorine is characterized by a large Damk\u00f6hler number, making the chemistry fast compared with the flow time scales. Hence, the product formation and temperature-rise in the flow is mixing limited. Both reacting and non-reacting simulations are performed with two turbulence models (Smagorinsky and Vreman) and the comparisons are made with the available experimental data. The reconstructed species concentrations, used in the flux evaluation, are limited using ideas from a recent paper by Zhang and Shu in order to ensure boundedness for these quantities. The simulations show close agreement of the velocity profiles and the temperature-rise profiles to those measured in the experiment.", "date": "2014-06-16", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2014-3030", "id_number": "CaltechAUTHORS:20190816-144342247", "isbn": "9781624102899", "book_title": "AIAA Aviation : 44th AIAA Fluid Dynamics Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190816-144342247", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2014-3030", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2014-3030", "pub_year": "2014", "author_list": "Kartha, Anand; Subbareddy, Pramod K.; et el." }, { "id": "https://authors.library.caltech.edu/records/8f2yc-80w42", "eprint_id": 97986, "eprint_status": "archive", "datestamp": "2023-08-20 01:28:07", "lastmod": "2023-10-18 16:56:26", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "GS-Sidarth", "name": { "family": "GS", "given": "Sidharth" } }, { "id": "Candler-G-V", "name": { "family": "Candler", "given": "Graham V." } }, { "id": "Dimotakis-P-E", "name": { "family": "Dimotakis", "given": "Paul E." } } ] }, "title": "Baroclinic Torque and Implications for Subgrid-Scale Modeling", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2014 American Institute of Aeronautics and Astronautics.", "abstract": "Baroclinic torque plays an important role in the dynamics of variable-density flows. Large eddy simulations using Favre-filtered resolved-scale velocities mask the explicit dependence of resolved-scale dynamics on subgrid-scale pressure-gradient-density interactions. The effect of subgrid-scale baroclinic torque on resolved scales is implicitly included in the subgrid-scale stress and subgrid-scale scalar fluxes through the resolved-scale vorticity it generates. LES closure models must therefore incorporate this effect in the computations. We explore the physics of subgrid-scale baroclinic torque within the structural framework of the Stretched-Vortex model. Fine-scale simulations of supersonic flows and direct numerical simulations of variable-density turbulence are investigated. Such flows have regions of active baroclinic torque and serve to set up flow configurations to assess the model.", "date": "2014-06-16", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2014-3214", "id_number": "CaltechAUTHORS:20190816-144342348", "isbn": "9781624102936", "book_title": "7th AIAA Theoretical Fluid Mechanics Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190816-144342348", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2014-3214", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2014-3214", "pub_year": "2014", "author_list": "GS, Sidharth; Candler, Graham V.; et el." }, { "id": "https://authors.library.caltech.edu/records/4ppbr-6rn17", "eprint_id": 97984, "eprint_status": "archive", "datestamp": "2023-08-20 01:27:59", "lastmod": "2023-10-18 16:56:21", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Rabinovitch-J", "name": { "family": "Rabinovitch", "given": "J." }, "orcid": "0000-0002-1914-7964" }, { "id": "Marx-V-M", "name": { "family": "Marx", "given": "V. M." } }, { "id": "Blanquart-G", "name": { "family": "Blanquart", "given": "G." }, "orcid": "0000-0002-5074-9728" } ] }, "title": "Pyrolysis Gas Composition for a Phenolic Impregnated Carbon Ablator Heatshield", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2014 by Jason Rabinovitch. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission. \n\nThe authors gratefully acknowledge funding from the Air Force Office of Scientific Research (Award FA9550-12-1-0472) under the supervision of Dr. Chiping Li. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the Air Force Office of Scientific Research or the U.S. Government. Financial support was also provided by the NSERC of Canada (postdoctoral fellowship to VMM).\n\nPublished - PyrolysisGasCompositionforaPhenolicImpregnatedCarbonAblatorHeatshield.pdf
", "abstract": "Published physical properties of phenolic impregnated carbon ablator (PICA) are compiled, and the composition of the pyrolysis gases that form at high temperatures internal to a heatshield is investigated. A link between the composition of the solid resin, and the composition of the pyrolysis gases created is provided. This link, combined with a detailed investigation into a reacting pyrolysis gas mixture, allows a consistent, and thorough description of many of the physical phenomena occurring in a PICA heatshield, and their implications, to be presented.", "date": "2014-06-16", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2014-2246", "id_number": "CaltechAUTHORS:20190816-144342150", "isbn": "9781624102813", "book_title": "AIAA Aviation : 11th AIAA/ASME Joint Thermophysics and Heat Transfer Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190816-144342150", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-12-1-0472" }, { "agency": "Natural Sciences and Engineering Research Council of Canada (NSERC)" } ] }, "other_numbering_system": { "items": [ { "id": "2014-2246", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2014-2246", "primary_object": { "basename": "PyrolysisGasCompositionforaPhenolicImpregnatedCarbonAblatorHeatshield.pdf", "url": "https://authors.library.caltech.edu/records/4ppbr-6rn17/files/PyrolysisGasCompositionforaPhenolicImpregnatedCarbonAblatorHeatshield.pdf" }, "pub_year": "2014", "author_list": "Rabinovitch, J.; Marx, V. M.; et el." }, { "id": "https://authors.library.caltech.edu/records/83crx-3sc95", "eprint_id": 98002, "eprint_status": "archive", "datestamp": "2023-08-20 01:25:48", "lastmod": "2023-10-18 16:57:05", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bitter-N-P", "name": { "family": "Bitter", "given": "N. P." } }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "J. E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "Transient Growth in Hypersonic Boundary Layers", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Aerodynamics, Fluids and Thermal Sciences", "note": "\u00a9 2014 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 13 Jun 2014. \n\nThe authors are grateful to Peter Schmid and Sasha Fedorov for very useful discussions regarding both modal and non-modal instabilities. This work was sponsored in part by AFOSR and NASA through the National Center for Hypersonic Research in Laminar-Turbulent Transition and also by AFOSR award number FA9550-10-1-0491. The views expressed herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of AFOSR or the U.S. Government.", "abstract": "This paper investigates the relative importance of modal and non-modal growth mechanisms in at-plate, hypersonic boundary layers as well as the effects of Mach number and wall cooling on these processes. Optimal disturbances are calculated in both the spatial and temporal frameworks using an eigenvector decomposition of the locally-parallel, linearized Navier-Stokes equations. It is found that for every Mach number there is an optimal level of wall cooling that minimizes transient growth; at this condition the wall temperature is slightly below the freestream temperature, with lower wall temperatures needed as the Mach number increases. The competition between modal and non-modal growth mechanisms is examined over a range of Reynolds numbers by calculating N factor curves for both processes. For conditions relevant to high enthalpy flows (high Mach number, cold wall), transient growth is rapidly overtaken by modal instabilities while the level of amplification remains small. At lower Mach numbers or adiabatic conditions, the transient growth is overtaken more slowly. For low Mach numbers and cold walls, no modal instabilities exist, but the level of non-modal amplification is increased such that the initiation of transition\nby infinitesimal perturbations is plausible despite the absence of modal instabilities.", "date": "2014-06-13", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2014-2497", "id_number": "CaltechAUTHORS:20190819-132915607", "isbn": "978-1-62410-293-6", "book_title": "7th AIAA Theoretical Fluid Mechanics Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190819-132915607", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-10-1-0491" }, { "agency": "NASA" } ] }, "other_numbering_system": { "items": [ { "id": "2014-2497", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2014-2497", "pub_year": "2014", "author_list": "Bitter, N. P. and Shepherd, J. E." }, { "id": "https://authors.library.caltech.edu/records/6xh1m-4tz08", "eprint_id": 98064, "eprint_status": "archive", "datestamp": "2023-08-20 01:25:56", "lastmod": "2023-10-18 17:00:37", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Schmidt-B-E", "name": { "family": "Schmidt", "given": "B. E." }, "orcid": "0000-0001-9193-7760" }, { "id": "Bitter-N-P", "name": { "family": "Bitter", "given": "N. P." } }, { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "H. G." }, "orcid": "0000-0002-4903-8419" }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "J. E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "Experimental Investigation of Gas Injection into the Boundary Layer on a Slender Body in Supersonic Flow", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2014 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 13 Jun 2014. \n\nThe authors would like to thank Dr. Nicholaus Parziale and Mr. Bahram Valiferdowsi for guidance and assistance in the laboratory. The authors would additionally like to acknowledge Dr. Joseph Jewell, Dr. Ivett Leyva, and Dr. Ross Wagnild for previous work done on this topic. Finally, the authors thank Dr. Alexander Fedorov for the concept of using a negative slope on the cone surface to compensate for injection. Without this key idea this work would not have been performed. This work was sponsored in part by AFOSR and NASA through the National Center for Hypersonic Research in Laminar-Turbulent Transition and also by AFOSR award number FA9550-10-1-0491. The views expressed herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of AFOSR or the U.S. Government.", "abstract": "A method for injection of gas into the boundary layer on a slender body in supersonic flow while minimizing perturbation to the mean flow is examined experimentally. Injection of gas is equivalent to a sudden increase in the displacement thickness of the boundary layer, which produces an oblique shock that propagates into the inviscid region of the flow. It is found that modification of the geometry of the body can compensate for the increased displacement thickness created by injection and minimize the production of oblique waves. However, the resulting near-wall injection layer is observed to be unstable and a turbulent boundary layer develops downstream of the injection region. The instability of the flow is examined using velocity profiles from a compressible Navier-Stokes computation. In-depth analysis of the mean flow and stability are performed by Fedorov in a companion paper.", "date": "2014-06-13", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2014-2496", "id_number": "CaltechAUTHORS:20190821-084310318", "isbn": "978-1-62410-293-6", "book_title": "7th AIAA Theoretical Fluid Mechanics Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190821-084310318", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-10-1-0491" }, { "agency": "NASA" } ] }, "other_numbering_system": { "items": [ { "id": "2014-2496", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2014-2496", "pub_year": "2014", "author_list": "Schmidt, B. E.; Bitter, N. P.; et el." }, { "id": "https://authors.library.caltech.edu/records/w0e6e-jdh61", "eprint_id": 71831, "eprint_status": "archive", "datestamp": "2023-08-20 01:15:34", "lastmod": "2023-10-23 17:14:43", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bandyopadhyay-S", "name": { "family": "Bandyopadhyay", "given": "Saptarshi" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Distributed Estimation using Bayesian Consensus Filtering", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2014 AACC. \n\nDate Added to IEEE Xplore: 21 July 2014. \n\nThis research was supported by AFOSR grant FA95501210193. An extended version of this paper has been submitted to IEEE Transactions on Automatic Control. (http://arxiv.org/abs/1403.3117) \n\nLast revised 13 Oct 2016. \n\nThe authors would like to thank F. Hadaegh, D. Bayard, S. Hutchinson, P. Voulgaris, M. Egerstedt, A. Gupta, A. Dani, D. Morgan, S. Sengupta, and A. Olshevsky for stimulating discussions about this paper.\n\nSubmitted - 1403.3117.pdf
", "abstract": "We present the Bayesian consensus filter (BCF) for tracking a moving target using a networked group of sensing agents and achieving consensus on the best estimate of the probability distributions of the target's states. Our BCF framework can incorporate nonlinear target dynamic models, heterogeneous nonlinear measurement models, non-Gaussian uncertainties, and higher-order moments of the locally estimated posterior probability distribution of the target's states obtained using Bayesian filters. If the agents combine their estimated posterior probability distributions using a logarithmic opinion pool, then the sum of Kullback\u2013Leibler divergences between the consensual probability distribution and the local posterior probability distributions is minimized. Rigorous stability and convergence results for the proposed BCF algorithm with single or multiple consensus loops are presented. Communication of probability distributions and computational methods for implementing the BCF algorithm are discussed along with a numerical example.", "date": "2014-06", "date_type": "published", "publisher": "IEEE", "place_of_pub": "New York, NY", "pagerange": "634-641", "id_number": "CaltechAUTHORS:20161108-152342060", "isbn": "978-1-4799-3272-6", "book_title": "American Control Conference (ACC), 2014", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161108-152342060", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA95501210193" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/ACC.2014.6858896", "primary_object": { "basename": "1403.3117.pdf", "url": "https://authors.library.caltech.edu/records/w0e6e-jdh61/files/1403.3117.pdf" }, "pub_year": "2014", "author_list": "Bandyopadhyay, Saptarshi and Chung, Soon-Jo" }, { "id": "https://authors.library.caltech.edu/records/hjpdq-4sn10", "eprint_id": 67592, "eprint_status": "archive", "datestamp": "2023-08-20 01:14:56", "lastmod": "2023-10-18 21:18:56", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Matheou-Georgios", "name": { "family": "Matheou", "given": "Georgios" }, "orcid": "0000-0003-4024-4571" }, { "id": "Dimotakis-P-E", "name": { "family": "Dimotakis", "given": "Paul E." } } ] }, "title": "Scalar excursions in large-eddy simulations", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2014 AIAA. \n\nThis work was supported by the AFOSR Grant No. FA9550-12-1-0461 and the John K. Northrop Chair of the California Institute of Technology. The authors would also like to acknowledge discussions and collaborations with Prof. G. Candler and his research group at the University of Minnesota and Prof. D. Meiron at Caltech. We would like to thank Dr. D. Chung (University of Melbourne) for making available the pseudo-spectral code used in this study.", "abstract": "The range of values of scalar fields in turbulent flows is bounded by their boundary values, for passive scalars, and by a combination of boundary values, reaction rates, phase\nchanges, etc., for active scalars. The current investigation focuses on the local conservation\nof passive scalar concentration fields and the ability of the large-eddy simulation (LES)\nmethod to observe the boundendness of concentrations of a passive scalar. In practice,\nthis fundamental constraint is often violated with scalar excursions exhibiting local under-\nand over-shoots in their values. The present study characterizes passive-scalar excursions\nin LES of a shear flow and examines methods for diagnosis and mitigation of the problem.\nThe analysis of scalar-excursion statistics provides support of the main hypothesis of the\ncurrent study that the unphysical scalar excursions in LES result from dispersive oscillations\nof the convection-term discretization at times and locations where the subgrid-scale model\nprovides insufficient dissipation to produce a sufficiently smooth scalar field. In the LES\nruns three parameters are varied: the discretization of the convection terms, the subgrid-scale (SGS) model, and the grid resolution. Scalar excursions are found to decrease as\nthe order of accuracy of non-dissipative schemes is increased, but the improvement rate\ndecreases with increasing order of accuracy. Two SGS models are utilized, the stretched-vortex and Smagorinsky and it is found that the more dissipative Smagorinsky model results\nin smaller excursions, although the magnitude of the excursions is strongly dependent on\nthe Smagorinsky constant. The maximum excursion and volume fraction of excursions\noutside boundary values show opposite trends with respect to resolution. The maximum\nexcursion increases as resolution increases, whereas the volume fraction decreases. The\nreason for the increase in the maximum excursion is statistical and is traceable to the\nnumber of grid points (sample size) which increases with resolution. In contrast, the\nvolume fraction of the excursions outside the boundary limits decreases with resolution\nbecause the SGS model performs better at higher grid resolutions.", "date": "2014-06", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "id_number": "CaltechAUTHORS:20160602-160140083", "isbn": "978-1-62410-293-6", "book_title": "7th AIAA Theoretical Fluid Mechanics Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160602-160140083", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-12-1-0461" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2014-3209", "pub_year": "2014", "author_list": "Matheou, Georgios and Dimotakis, Paul E." }, { "id": "https://authors.library.caltech.edu/records/49evn-kr703", "eprint_id": 72278, "eprint_status": "archive", "datestamp": "2023-08-20 01:15:42", "lastmod": "2023-10-23 20:35:05", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Yu-Jingjin", "name": { "family": "Yu", "given": "Jingjin" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Voulgaris-P-G", "name": { "family": "Voulgaris", "given": "Petros G." } } ] }, "title": "Distance optimal target assignment in robotic networks under communication and sensing constraints", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2014 IEEE. \n\nDate of Conference: 31 May-7 June 2014. Date Added to IEEE Xplore: 29 September 2014. \n\nThis work was supported in part by AFOSR grant FA95501210193 and NSF grant IIS-1253758. This paper is intended as an early dissemination of results of an extended draft [32] which contains more complete proofs and significant generalizations. We thank the reviewers for their constructive comments.", "abstract": "We study the problem of minimizing the total distance incurred in assigning a group of mobile robots to an equal number of static targets. Assuming that the robots have limited, range-based communication and target-sensing capabilities, we present a necessary and sufficient condition for ensuring distance optimality when robots and targets are uniformly randomly distributed. We then provide an explicit, non-asymptotic formula for computing the number of robots needed for guaranteeing optimality in terms of the robots' sensing and communication capabilities with arbitrarily high probabilities. The bound given in the formula is also asymptotically tight. Due to the large number of robots needed for high-probability optimality guarantee, we continue to investigate strategies for cases in which the number of robots cannot be freely chosen. We show that a properly designed strategy can be asymptotically optimal or suboptimal with constant approximation ratios.", "date": "2014-06", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "1098-1105", "id_number": "CaltechAUTHORS:20161123-103752838", "isbn": "978-1-4799-3685-4", "book_title": "IEEE International Conference on Robotics and Automation (ICRA), 2014", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161123-103752838", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA95501210193" }, { "agency": "NSF", "grant_number": "IIS-1253758" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/ICRA.2014.6906991", "pub_year": "2014", "author_list": "Yu, Jingjin; Chung, Soon-Jo; et el." }, { "id": "https://authors.library.caltech.edu/records/jr1tb-f2e52", "eprint_id": 72277, "eprint_status": "archive", "datestamp": "2023-08-20 00:50:32", "lastmod": "2023-10-23 20:34:59", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Yu-Jingjin", "name": { "family": "Yu", "given": "Jingjin" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Voulgaris-P-G", "name": { "family": "Voulgaris", "given": "Petros G." } } ] }, "title": "Traveled distance minimization and hierarchical strategies for robotic networks", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2014 IEEE. \n\nDate of Conference: 21-23 May 2014. Date Added to IEEE Xplore: 14 August 2014. \n\nThis work was supported in part by AFOSR grant FA95501210193 and NSF grant IIS-1253758.", "abstract": "We study the distance optimal assignment of n mobile robots to an equal number of targets under communication and target-sensing constraints. Extending previous results over uniform distributions, we show that when the robots and targets assume the same but arbitrary distribution over the unit square, a carefully designed distributed hierarchical strategy has expected travel distance that matches the best known upper bound assuming global communication and infinite target-sensing range. In a sense, our result shows that for target assignment problems in robotic networks, local optimality also offers good guarantees on global optimality.", "date": "2014-05", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "491-496", "id_number": "CaltechAUTHORS:20161123-102301602", "isbn": "978-1-4799-2890-3", "book_title": "6th International Symposium on Communications, Control and Signal Processing (ISCCSP), 2014", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161123-102301602", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA95501210193" }, { "agency": "NSF", "grant_number": "IIS-1253758" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/ISCCSP.2014.6877920", "pub_year": "2014", "author_list": "Yu, Jingjin; Chung, Soon-Jo; et el." }, { "id": "https://authors.library.caltech.edu/records/mr74c-7qt42", "eprint_id": 79208, "eprint_status": "archive", "datestamp": "2023-08-20 00:30:12", "lastmod": "2023-10-26 14:41:40", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Pandolfi-A", "name": { "family": "Pandolfi", "given": "A." }, "orcid": "0000-0002-7084-7456" }, { "id": "Li-B", "name": { "family": "Li", "given": "B." } }, { "id": "Ortiz-M", "name": { "family": "Ortiz", "given": "M." }, "orcid": "0000-0001-5877-4824" } ] }, "title": "Modeling fracture by material-point erosion", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2014 Springer International Publishing Switzerland. \n\nFirst Online: 30 April 2014.", "abstract": "The present work is concerned with the verification and validation of an implementation of the eigenfracture scheme of Schmidt et al. (SIAM J Multi-scale Model Simul 7:1237\u20131266, 2009) based on material-point erosion, which we refer to as eigenerosion. Eigenerosion is derived from the general eigenfracture scheme by restricting the eigendeformations in a binary sense: they can be either zero, in which case the local behavior is elastic; or they can be equal to the local displacement gradient, in which case the corresponding material neighborhood is failed, or eroded. When combined with a material-point spatial discretization, this scheme gives rise to material-point erosion, i. e., each material point can be either intact, in which case its behavior is elastic, or be completely failed\u2014or eroded\u2014and has no load bearing capacity. We verify the eigenerosion scheme through convergence studies for mode I fracture propagation in three-dimensional problems. By way of validation we apply the eigene-rosion scheme to the simulation of combined torsion- traction experiments in aluminum-oxide bars.", "date": "2014-04-30", "date_type": "published", "publisher": "Springer", "place_of_pub": "Cham, Switzerland", "pagerange": "3-16", "id_number": "CaltechAUTHORS:20170719-112646074", "isbn": "978-3-319-04396-8", "book_title": "Fracture Phenomena in Nature and Technology", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170719-112646074", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Bigoni-D", "name": { "family": "Bigoni", "given": "Davide" } }, { "id": "Carini-A", "name": { "family": "Carini", "given": "Angelo" } }, { "id": "Gei-M", "name": { "family": "Gei", "given": "Massimiliano" } }, { "id": "Salvadori-A", "name": { "family": "Salvadori", "given": "Alberto" } } ] }, "doi": "10.1007/978-3-319-04397-5_2", "pub_year": "2014", "author_list": "Pandolfi, A.; Li, B.; et el." }, { "id": "https://authors.library.caltech.edu/records/kv9tb-zp895", "eprint_id": 52091, "eprint_status": "archive", "datestamp": "2023-08-19 23:12:56", "lastmod": "2023-10-18 19:33:15", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ponga-Mauricio", "name": { "family": "Ponga", "given": "Mauricio" }, "orcid": "0000-0001-5058-1454" }, { "id": "Ariza-Pilar", "name": { "family": "Ariza", "given": "Pilar" }, "orcid": "0000-0003-0266-0216" }, { "id": "Ortiz-M", "name": { "family": "Ortiz", "given": "Michael" }, "orcid": "0000-0001-5877-4824" }, { "id": "Bhattacharya-K", "name": { "family": "Bhattacharya", "given": "Kaushik" }, "orcid": "0000-0003-2908-5469" } ] }, "title": "Linear Scaling DFT for defects in metals", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Multiscale Modeling of Materials, Crystals Defects, Quantum Mechanics, Density Functional Theory, Linear Scaling DFT", "note": "\u00a9 2014 Wiley & Sons, Inc. \n\nPublished Online: 24 Jan 2014.Published Print: 1 Feb 2014. \n\nThis work was part of the thesis of MP at the University of Seville and was supported by the Ministerio de Ciencia e Innovaci\u03ccn of Spain (DPI2009-14305-C02-01) and the support of\nthe Consejer\u00eda de Innovaci\u03ccn of Junta de Andaluc\u00eda (P09-TEP-4493). This research was also sponsored by the US Army Research Laboratory and was accomplished under Cooperative\nAgreement Number W9llNF-12-2-0022.", "abstract": "This work presents a study of defects in solid using Density Functional Theory (DFT) as the only input to predict its information energies. The method used, called the Linnear Scaling Spectral Gauss Quadrature (LSSGQ), has linear scaling with the number of atoms for insulators as well as for metals. This behaviour allows us to stimulate relatively large systems in a fraction of the time demanded by other traditional DFT methods. We demostrate the effectiveness of the method, the linear scaling of large problems and also the size dependence in the formation energy of defects through the simulation of (001) surface relaxation and single vacancy in Body Centered Cubic (BCC) Sodium crystals.", "date": "2014-01-24", "date_type": "published", "publisher": "John Wiley & Sons, Inc.", "place_of_pub": "Hoboken, New Jersey", "pagerange": "265-272", "id_number": "CaltechAUTHORS:20141124-095544294", "isbn": "9781118889725", "book_title": "Annual Meeting Supplemental Proceedings", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141124-095544294", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Ministerio de Ciencia e Innovaci\u03ccn (MCINN)", "grant_number": "DPI2009-14305-C02-01" }, { "agency": "Consejer\u00eda de Innovaci\u03ccn of Junta de Andaluc\u00eda", "grant_number": "P09-TEP-4493" }, { "agency": "Army Research Laboratory", "grant_number": "W9llNF-12-2-0022" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1002/9781118889879.ch35", "pub_year": "2014", "author_list": "Ponga, Mauricio; Ariza, Pilar; et el." }, { "id": "https://authors.library.caltech.edu/records/k3snx-91309", "eprint_id": 98046, "eprint_status": "archive", "datestamp": "2023-08-19 23:05:03", "lastmod": "2023-10-18 16:59:42", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Arya-M", "name": { "family": "Arya", "given": "Manan" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Deployment mechanics of highly compacted thin membrane structures", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2014 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 10 Jan 2014.", "abstract": "We studied the effects of membrane thickness and crease density on the forces required to unfold creased membrane structures. 26 cm-diameter models were made using two different thicknesses (7.5 \u03bcm and 25 \u03bcm) of polyimide film, and wrapped around a 4 cm-diameter hub using two different crease densities. They were deployed quasi-statically, and the deployment forces were measured. Two regimes were observed: an initial phase (up to about 85% deployed) of low and variable stiffness, and a second phase (above 85% deployed) of high stiffness. The thinner membrane models required higher deployment forces than the thicker membrane models during the initial phase.", "date": "2014-01-10", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2014-1038", "id_number": "CaltechAUTHORS:20190820-141521974", "isbn": "978-1-62410-319-3", "book_title": "Spacecraft Structures Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190820-141521974", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2014-1038", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2014-1038", "pub_year": "2014", "author_list": "Arya, Manan and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/m81n5-j3r80", "eprint_id": 98830, "eprint_status": "archive", "datestamp": "2023-08-19 23:05:10", "lastmod": "2023-10-18 17:40:16", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Brownstein-I-D", "name": { "family": "Brownstein", "given": "Ian D." } }, { "id": "Szlatenyi-C-S", "name": { "family": "Szlatenyi", "given": "Christopher S." } }, { "id": "Breuer-K-S", "name": { "family": "Breuer", "given": "Kenny S." } } ] }, "title": "Enhanced Aerodynamic Performance of a Wind Turbine Airfoil Section using Plasma Actuation", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2014 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 10 Jan 2014.", "abstract": "The aerodynamic effects of a dual plasma actuator arrangement on a GOE 735, 23% thickness\nairfoil, modeled after a Renewegy VP-20 wind turbine blade cross section, were studied. Experiments\ndemonstrating actuator thrust capabilities are compared to previous reports to better\nunderstand the relationship between actuator geometry and performance. Characterizations of\nthe effects of plasma actuators for aerodynamic flow control on the resultant coefficient of lift\nand drag curves are discussed at Re = 1.50 x 10^5. Additionally, the dual plasma actuator arrangement\nwas tested at various applied voltage amplitudes, ranging from 1-9kV_(rms) and frequencies\nranging from 2-6kHz at Re = 1.50 x 10^4 to study the aerodynamic effects and the electrical costs\nof this type of flow control. The voltage and current waveforms were sampled during 10s measurements\nso that the power dissipated by the actuators could be calculated. Relationships\nbetween the thrust produced by the actuators, the voltage amplitude and frequency, the coefficient\nof lift just before stall, and the dissipated power are discussed. In addition the effects of\nmultiple actuators, the coefficient of drag just before stall, and the phase offsets of the voltage\nand current signals are discussed.", "date": "2014-01-10", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2014-1244", "id_number": "CaltechAUTHORS:20190924-103614059", "isbn": "978-1-62410-256-1", "book_title": "52nd Aerospace Sciences Meeting", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190924-103614059", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2014-1244", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2014-1244", "pub_year": "2014", "author_list": "Brownstein, Ian D.; Szlatenyi, Christopher S.; et el." }, { "id": "https://authors.library.caltech.edu/records/aqx0m-7g324", "eprint_id": 98045, "eprint_status": "archive", "datestamp": "2023-08-19 23:05:00", "lastmod": "2023-10-18 16:59:39", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lee-Nicolas", "name": { "family": "Lee", "given": "Nicolas" }, "orcid": "0000-0001-5500-1324" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Self-Supporting Membrane Structures with Curved Creases for Smooth Packaging and Deployment", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2014 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 10 Jan 2014.", "abstract": "We present a design for a deployable multi-layered membrane structure that uses a curved crease pattern to enable smooth wrapping around a spool. The crease pattern is parameterized to enable a variety of designs, and a specific implementation was selected based on an existing patch antenna array design. We constructed a prototype structure based on this geometry, and conducted deployment tests to measure the deployment force profile required to unfold the structure and to unwrap it from a spool. We find that the deployment force for unwrapping is significantly higher than for unfolding. These force profiles are repeatable over multiple deployments and the global trends do not depend on deployment rates over the range tested, between 1 and 8 mm/s. However, the local dynamic behavior can depend on deployment rate.", "date": "2014-01-10", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2014-1037", "id_number": "CaltechAUTHORS:20190820-140510587", "isbn": "978-1-62410-319-3", "book_title": "Spacecraft Structures Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190820-140510587", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2014-1037", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2014-1037", "pub_year": "2014", "author_list": "Lee, Nicolas and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/3j86n-70n38", "eprint_id": 97903, "eprint_status": "archive", "datestamp": "2023-08-19 22:58:50", "lastmod": "2023-10-18 16:51:54", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Costantine-J", "name": { "family": "Costantine", "given": "J." } }, { "id": "Tawk-Y", "name": { "family": "Tawk", "given": "Y." } }, { "id": "Ayoub-F", "name": { "family": "Ayoub", "given": "F." }, "orcid": "0000-0002-7389-8400" }, { "id": "Christodoulou-C-G", "name": { "family": "Christodoulou", "given": "C. G." } }, { "id": "Olson-G", "name": { "family": "Olson", "given": "G." } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "S." }, "orcid": "0000-0001-9373-3278" } ] }, "title": "UHF deployable antenna structures for CubeSats", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2014 IEEE.", "abstract": "Antenna design for small satellites such as CubeSats constitute a challenge for designers especially at UHF frequencies. The small size of the CubeSat (10 cm x 10 cm x 10 cm) imposes several constraints on the antenna design. Extreme packaging ratios and advanced deployment mechanisms have to be employed to cater for UHF antennas on a CubeSat platform.", "date": "2014-01", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "1", "id_number": "CaltechAUTHORS:20190814-154556302", "isbn": "9781479931200", "book_title": "2014 United States National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190814-154556302", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/usnc-ursi-nrsm.2014.6928057", "pub_year": "2014", "author_list": "Costantine, J.; Tawk, Y.; et el." }, { "id": "https://authors.library.caltech.edu/records/w4jnp-wcm64", "eprint_id": 44486, "eprint_status": "archive", "datestamp": "2023-08-19 22:54:57", "lastmod": "2023-10-26 14:20:25", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lee-Nicolas", "name": { "family": "Lee", "given": "Nicolas" }, "orcid": "0000-0001-5500-1324" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Multi-layered membrane structures with curved creases for smooth packaging and deployment", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2014 AIAA.\n\nN. Lee was supported through this work by a postdoctoral fellowship from the W. M. Keck Institute for Space\nStudies. We thank P. Arakelian for his assistance with the experimental setup.", "abstract": "We present a design for a deployable multi-layered membrane structure that uses a curved crease pattern\nto enable smooth wrapping around a spool. The crease pattern is parameterized to enable a variety of designs,\nand a specific implementation was selected based on an existing patch antenna array design. We constructed a\nprototype structure based on this geometry, and conducted deployment tests to measure the deployment force\nprofile required to unfold the structure and to unwrap it from a spool. We find that the deployment force\nfor unwrapping is significantly higher than for unfolding. These force profiles are repeatable over multiple\ndeployments and the global trends do not depend on deployment rates over the range tested, between 1 and\n8 mm/s. However, the local dynamic behavior can depend on deployment rate.", "date": "2014-01", "date_type": "published", "id_number": "CaltechAUTHORS:20140324-181344254", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140324-181344254", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Keck Institute for Space Studies (KISS)" } ] }, "other_numbering_system": { "items": [ { "id": "2014-1037", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "Keck-Institute-for-Space-Studies" }, { "id": "GALCIT" } ] }, "doi": "10.2514/6.2014-1037", "pub_year": "2014", "author_list": "Lee, Nicolas and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/pj4qv-41q73", "eprint_id": 72273, "eprint_status": "archive", "datestamp": "2023-08-19 22:08:12", "lastmod": "2024-01-13 20:20:50", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Panahandeh-Ghazaleh", "name": { "family": "Panahandeh", "given": "Ghazaleh" } }, { "id": "Meier-K-C", "name": { "family": "Meier", "given": "Kevin C." }, "orcid": "0000-0003-4000-1422" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Shi-Xichen", "name": { "family": "Shi", "given": "Xichen" } }, { "id": "Hutchinson-Seth", "name": { "family": "Hutchinson", "given": "Seth" }, "orcid": "0000-0002-3949-6061" } ] }, "title": "Motion Primitives and 3-D Path Planning for Fast Flight through a Forest", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2013 IEEE. \n\nThis research was funded by ONR N00014-11-1-0088 and NSF IIS-1253758. \n\nThe authors gratefully acknowledge the contributions of Sunil Patel, undergraduate student in the Department of Aerospace Engineering, to the experiments reported in this paper.", "abstract": "This paper addresses the problem of motion planning for fast, agile flight through a dense obstacle field. A key contribution is the design of two families of motion primitives for aerial robots flying in dense obstacle fields, along with rules to stitch them together. The primitives are obtained by solving for the flight dynamics of the aerial robot, and explicitly account for limited agility using time delays. The first family of primitives consists of turning maneuvers to link any two points in space. The locations of the terminal points are used to obtain closed-form expressions for the control inputs required to fly between them, while accounting for the finite time required to switch between consecutive sets of control inputs. The second family consists of aggressive turn-around maneuvers wherein the time delay between the angle of attack and roll angle commands is used to optimize the maneuver for the spatial constraints. A 3-D motion planning algorithm based on these primitives is presented for aircraft flying through a dense forest.", "date": "2013-11", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "2940-2947", "id_number": "CaltechAUTHORS:20161123-070853922", "isbn": "978-1-4673-6358-7", "book_title": "IEEE/RSJ International Conference on Intelligent Robots and Systems, 2013", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161123-070853922", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-11-1-0088" }, { "agency": "NSF", "grant_number": "IIS-1253758" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Amato-N", "name": { "family": "Amato", "given": "N." } } ] }, "doi": "10.1109/IROS.2013.6696773", "pub_year": "2013", "author_list": "Panahandeh, Ghazaleh; Meier, Kevin C.; et el." }, { "id": "https://authors.library.caltech.edu/records/mj4n8-bmt27", "eprint_id": 72272, "eprint_status": "archive", "datestamp": "2023-08-19 22:08:05", "lastmod": "2023-10-23 20:34:35", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Dani-Ashwin-P", "name": { "family": "Dani", "given": "Ashwin P." } }, { "id": "Panahandeh-Ghazaleh", "name": { "family": "Panahandeh", "given": "Ghazaleh" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Hutchinson-Seth", "name": { "family": "Hutchinson", "given": "Seth" }, "orcid": "0000-0002-3949-6061" } ] }, "title": "Image Moments for Higher-Level Feature Based Navigation", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2013 IEEE. \n\nThis project was supported by the Office of Naval Research (ONR) under Award No. N00014-11-1-0088.", "abstract": "This paper presents a novel vision-based localization and mapping algorithm using image moments of region features. The environment is represented using regions, such as planes and/or 3D objects instead of only a dense set of feature points. The regions can be uniquely defined using a small number of parameters; e.g., a plane can be completely characterized by normal vector and distance to a local coordinate frame attached to the plane. The variation of image moments of the regions in successive images can be related to the parameters of the regions. Instead of tracking a large number of feature points, variations of image moments of regions can be computed by tracking the segmented regions or a few feature points on the objects in successive images. A map represented by regions can be characterized using a minimal set of parameters. The problem is formulated as a nonlinear filtering problem. A new discrete-time nonlinear filter based on the state-dependent coefficient (SDC) form of nonlinear functions is presented. It is shown via Monte-Carlo simulations that the new nonlinear filter is more accurate and consistent than EKF by evaluating the root-mean squared error (RMSE) and normalized estimation error squared (NEES).", "date": "2013-11", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "602-609", "id_number": "CaltechAUTHORS:20161123-064941445", "isbn": "978-1-4673-6358-7", "book_title": "IEEE/RSJ International Conference on Intelligent Robots and Systems, 2013", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161123-064941445", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-11-1-0088" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Amato-N", "name": { "family": "Amato", "given": "N." } } ] }, "doi": "10.1109/IROS.2013.6696413", "pub_year": "2013", "author_list": "Dani, Ashwin P.; Panahandeh, Ghazaleh; et el." }, { "id": "https://authors.library.caltech.edu/records/h9ysw-tmq47", "eprint_id": 73100, "eprint_status": "archive", "datestamp": "2023-08-19 22:08:20", "lastmod": "2024-01-13 20:22:22", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Yang-Junho", "name": { "family": "Yang", "given": "Junho" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Hutchinson-Seth", "name": { "family": "Hutchinson", "given": "Seth" }, "orcid": "0000-0002-3949-6061" }, { "id": "Johnson-David", "name": { "family": "Johnson", "given": "David" } }, { "id": "Kise-Michio", "name": { "family": "Kise", "given": "Michio" } } ] }, "title": "Vision-Based Localization and Mapping for an Autonomous Mower", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2013 IEEE. \n\nDate Added to IEEE Xplore: 06 January 2014. \n\nThis material is based on work supported by John Deere. The authors acknowledge Dr. Ashwin Dani for useful discussions on designing the observer. The authors also thank Colin Das for his help on the experiments.", "abstract": "This paper presents a vision-based localization and mapping algorithm for an autonomous mower. We divide the task for robotic mowing into two separate phases, a teaching phase and a mowing phase. During the teaching phase, the mower estimates the 3D positions of landmarks and defines a boundary in the lawn with an estimate of its own trajectory. During the mowing phase, the location of the mower is estimated using the landmark and boundary map acquired from the teaching phase. Of particular interest for our work is ensuring that the estimator for landmark mapping will not fail due to the nonlinearity of the system during the teaching phase. A nonlinear observer is designed with pseudo-measurements of each landmark's depth to prevent the map estimator from diverging. Simultaneously, the boundary is estimated with an EKF. Measurements taken from an omnidirectional camera, an IMU, and a ground speed sensor are used for the estimation. Numerical simulations and offline teaching phase experiments with our autonomous mower demonstrate the potential of our algorithm.", "date": "2013-11", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "3655-3662", "id_number": "CaltechAUTHORS:20161221-141750231", "isbn": "978-1-4673-6358-7", "book_title": "2013 IEEE/RSJ International Conference on Intelligent Robots and Systems", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161221-141750231", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "John Deere" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/IROS.2013.6696878", "pub_year": "2013", "author_list": "Yang, Junho; Chung, Soon-Jo; et el." }, { "id": "https://authors.library.caltech.edu/records/rtzbs-ypj97", "eprint_id": 103342, "eprint_status": "archive", "datestamp": "2023-08-22 10:41:18", "lastmod": "2024-01-15 04:30:33", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Alkhader-M", "name": { "family": "Alkhader", "given": "Maen" } }, { "id": "Knauss-W-G", "name": { "family": "Knauss", "given": "Wolfgang" } }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "Guruswami" }, "orcid": "0000-0002-2912-0001" } ] }, "title": "Experimental Investigation of Failure in Viscoelastic Elastomers Under Combined Shear and Pressure", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Failure; Viscoelastic elastomers; Combined loading; High-strain-rate", "note": "\u00a9 2013 The Society for Experimental Mechanics. \n\nFirst Online: 25 October 2013. \n\nThe authors wish to thank Dr. Roshdy Barsoum of the Office of Naval Research through his guidance and cooperation and for the sustained support of this difficult effort under Grant ONR N00014-07-1-0624.", "abstract": "An experimental approach, based on Split Hopkinson Pressure Bar (SHPB) apparatus, is developed to elucidate failure of viscoelastic elastomers under combined shear and high pressures such as are encountered in explosive and/or armor-impact scenarios. In this experimental arrangement, thin cylindrical polyurea specimens with an aspect ratio (Diameter to thickness) greater or equal to 15 are tested, up to failure, using Split Hopkinson Pressure Bar (SHPB). Specimens with large aspect ratio are used to guarantee the close approximation of a triaxial state of stress in the specimen upon loading; hence the measured normal stress would be approximately equal to the hydrostatic pressure in the specimen. Friction at the loading interfaces forces the stress state to deviate from uniformity, restrict both the circumferential and radial displacements and lead to the development of shear stresses and strains. Hence, induced failure occurs under conditions combining high-strain-rate, high pressure and shear stresses. By using this setup, repeatable failure modes were detected and elucidated using finite element simulations.", "date": "2013-10-25", "date_type": "published", "publisher": "Springer", "place_of_pub": "New York, NY", "pagerange": "55-62", "id_number": "CaltechAUTHORS:20200520-074532493", "isbn": "978-1-4614-4240-0", "book_title": "Challenges in Mechanics of Time-Dependent Materials and Processes in Conventional and Multifunctional Materials", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200520-074532493", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-07-1-0624" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Antoun-B", "name": { "family": "Antoun", "given": "Bonnie" } }, { "id": "Qi-H-Jerry", "name": { "family": "Qi", "given": "H. Jerry" } }, { "id": "Hall-Richard", "name": { "family": "Hall", "given": "Richard" } }, { "id": "Tandon-G-P", "name": { "family": "Tandon", "given": "G. P." } }, { "id": "Lu-Hongbing", "name": { "family": "Lu", "given": "Hongbing" } }, { "id": "Lu-Charles", "name": { "family": "Lu", "given": "Charles" } } ] }, "doi": "10.1007/978-1-4614-4241-7_8", "pub_year": "2013", "author_list": "Alkhader, Maen; Knauss, Wolfgang; et el." }, { "id": "https://authors.library.caltech.edu/records/fxmbq-wp580", "eprint_id": 48906, "eprint_status": "archive", "datestamp": "2023-08-19 21:42:56", "lastmod": "2023-10-17 20:31:51", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Guala-Michele", "name": { "family": "Guala", "given": "Michele" } }, { "id": "LeHew-Jeff", "name": { "family": "LeHew", "given": "Jeff" } }, { "id": "Metzger-Meredith", "name": { "family": "Metzger", "given": "Meredith" } }, { "id": "McKeon-B-J", "name": { "family": "McKeon", "given": "Beverley J." }, "orcid": "0000-0003-4220-1583" } ] }, "title": "On the structure of wall turbulence in the thermally neutral atmospheric surface layer", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2013 by John Wiley & Sons.", "abstract": "Recent experimental investigations of the canonical turbulent boundary layer at high Reynolds numbers has provided evidence on the active role of very large\u2010scale structures, extending in the streamwise direction for several boundary layer heights, and modulating near\u2010wall turbulence from the energy containing eddy scales down to the dissipative scales. However, the physical mechanisms governing such interactions are not completely clear yet, and the reason may be related to the fact that the structure of wall turbulence at high Reynolds numbers still deserves further investigation. In this contribution we present recent results on the structural population in wall turbulence. We compare statistical trends obtained in two very different Reynolds number experiments, one in the atmospheric surface layer at SLTEST and one in a flat plate turbulent boundary layer. While the very large\u2010scale structures of turbulence and the near\u2010wall turbulent streaks are observed to have a well\u2010defined location in physical space and in the energetic domain, based on the frequency or wave number spectra, the intermediate scale motions that manifest as ramplike structures still seem to suffer from Reynolds number effects. Results suggest that outer scaling may not be appropriate, implying that ramplike structures are more likely confined to the near\u2010wall region in very high Reynolds\u2010number flows such as the atmospheric surface layer. Spatially resolved measurements at high Reynolds numbers are needed to univocally define the correct scaling of ramplike structures and to assess Reynolds number effects in the structural description of zero pressure gradient turbulent boundary layers.", "date": "2013-10", "date_type": "published", "publisher": "Wiley-Blackwell", "place_of_pub": "Hoboken, NJ", "pagerange": "97-109", "id_number": "CaltechAUTHORS:20140826-104525799", "isbn": "9781119962779", "book_title": "Coherent Flow Structures at Earth's Surface", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140826-104525799", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Venditti-Jeremy-G", "name": { "family": "Venditti", "given": "Jeremy G." } }, { "id": "Best-James-L", "name": { "family": "Best", "given": "James L." } }, { "id": "Church-Michael", "name": { "family": "Church", "given": "Michael" } }, { "id": "Hardy-Richard-J", "name": { "family": "Hardy", "given": "Richard J." } } ] }, "doi": "10.1002/9781118527221.ch7", "pub_year": "2013", "author_list": "Guala, Michele; LeHew, Jeff; et el." }, { "id": "https://authors.library.caltech.edu/records/2c5md-h6m32", "eprint_id": 98072, "eprint_status": "archive", "datestamp": "2023-08-19 21:46:50", "lastmod": "2023-10-18 17:01:06", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hegyi-D", "name": { "family": "Hegyi", "given": "Dezso" } }, { "id": "Li-Jun", "name": { "family": "Li", "given": "Jun" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Failure of Polyethylene Thin Film Membrane Structures", "ispublished": "unpub", "full_text_status": "public", "keywords": "StratoFilm, J-integral, Viscoelasticity, Free Volume Model", "note": "\u00a9 2013 CIMNE.\n\nWe thank Prof. W. Knauss for helpful comments and advice. DH research at the California Institute of Technology was supported by an Imre Koranyi Civi Engineering Fellowship from the Thomas Cholnoky Foundation. Financial support from the NASA Balloon Research Program is gratefully acknowledged.\n\nPublished - 2013_Failureofpolyethilenthinfilmmembranestructures.pdf
", "abstract": "The failure of balloons made of Linear Low Density PolyEthylene (LLDPE) is investigated. The chosen film is 38 \u03bcm thick StratoFilm 420, currently used for the NASA Super-Pressure balloons [1]. The visco-elastic behaviour of the film has been extensively studied and is already accounted for in the balloon design [2, 3, 5]. The next step in the development of accurate predictive tools for super-pressure balloons requires models that capture the transition from visco-elastic and visco-plastic behaviour to fracture. It is shown that realistic estimates of failure of LLDPE membrane structures can be obtained from visco-elastic simulations based on the non-linear visco-elastic model of the balloon film proposed by Kwok [5], supplemented with a fracture resistance criterion derived from the experimentally-based J-integral.", "date": "2013-10", "date_type": "published", "publisher": "CIMNE", "place_of_pub": "Barcelona", "pagerange": "1-16", "id_number": "CaltechAUTHORS:20190821-102001622", "isbn": "9788494168604", "book_title": "Structural Membranes 2013", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190821-102001622", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Thomas Cholnoky Foundation" }, { "agency": "NASA" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Bletzinger-K-U", "name": { "family": "Bletzinger", "given": "K.-U." } }, { "id": "Kr\u00f6plin-B", "name": { "family": "Kr\u00f6plin", "given": "B." } }, { "id": "O\u00f1ate-E", "name": { "family": "O\u00f1ate", "given": "E." } } ] }, "primary_object": { "basename": "2013_Failureofpolyethilenthinfilmmembranestructures.pdf", "url": "https://authors.library.caltech.edu/records/2c5md-h6m32/files/2013_Failureofpolyethilenthinfilmmembranestructures.pdf" }, "pub_year": "2013", "author_list": "Hegyi, Dezso; Li, Jun; et el." }, { "id": "https://authors.library.caltech.edu/records/88c6e-96w15", "eprint_id": 78794, "eprint_status": "archive", "datestamp": "2023-08-22 10:08:30", "lastmod": "2023-10-26 00:23:58", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bitter-N-P", "name": { "family": "Bitter", "given": "Neal P." } }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "Joseph E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "Dynamic Buckling of Submerged Tubes due to Impulsive External Pressure", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Dynamic buckling; Fluid-structure interaction; Buckling threshold; Imperfect structures; Impulsive loads", "note": "\u00a9 2014 The Society for Experimental Mechanics, Inc. \n\nFirst Online: 22 August 2013. \n\nThis research was supported by the Office of Naval Research DOD MURI on Mechanics and Mechanisms of Impulse Loading, Damage and Failure of Marine Structures and Materials (ONR Grant No. N00014-06-1-0730), program manager Dr. Y. D. S. Rajapakse. Tomohiro Nishiyama of the Japan Patent Office and Prof. Kazuaki Inaba, currently at the Tokyo Institute of Technology, executed the initial design of the annular tube implosion fixture and supervised its fabrication while working at Caltech. Preliminary experiments on buckling using this facility were conducted by Mr. Jason Damazo and Dr. Rafal Porowski, currently at the research Center for Fire Protection in Poland. We are also grateful to Prof. Ravichandran of Caltech, who provided technical advice and leadership of the Caltech MURI.", "abstract": "An annular geometry is used to experimentally study fluid-structure interaction and dynamic buckling of tubes submerged in water and subjected to axially-propagating pressure waves. Wave propagation, vibration, and buckling of the specimen tubes are characterized using pressure and strain measurements. Emphasis is placed on pressures near or slightly exceeding the buckling threshold, where buckling deformation is excited but remains elastic or only slightly plastic due to the short duration of the pressure pulse. Measured wave speeds and non-axisymmetric vibration frequencies are in good agreement with predictions from simple fluid-structure interaction models. Near the buckling threshold, the amplitude of non-axisymmetric deformation is observed to grow rapidly with small increases in pressure until plastic deformation occurs, which results in a substantial loss of strength of the tube. Systematic mode 2 variations in wall thickness are found to control the buckle orientation, since the major axis of mode 2 buckles is always aligned with the location where the tube wall is thinnest.", "date": "2013-08-22", "date_type": "published", "publisher": "Springer", "place_of_pub": "Cham, Switzerland", "pagerange": "225-236", "id_number": "CaltechAUTHORS:20170706-084659680", "isbn": "978-3-319-00770-0", "book_title": "Dynamic Behavior of Materials", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170706-084659680", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-06-1-0730" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Song-Bo", "name": { "family": "Song", "given": "Bo" } }, { "id": "Casem-D", "name": { "family": "Casem", "given": "Dan" } }, { "id": "Kimberley-J", "name": { "family": "Kimberley", "given": "Jamie" } } ] }, "doi": "10.1007/978-3-319-00771-7_28", "pub_year": "2013", "author_list": "Bitter, Neal P. and Shepherd, Joseph E." }, { "id": "https://authors.library.caltech.edu/records/znww4-fsn43", "eprint_id": 99032, "eprint_status": "archive", "datestamp": "2023-08-19 20:59:21", "lastmod": "2023-10-18 17:48:17", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Brinkmeyer-A", "name": { "family": "Brinkmeyer", "given": "A." } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "S." }, "orcid": "0000-0001-9373-3278" }, { "id": "Weaver-P-M", "name": { "family": "Weaver", "given": "P. M." } }, { "id": "Santer-M", "name": { "family": "Santer", "given": "M." } } ] }, "title": "Effects of Viscoelasticity on the Deployment of Bistable Tape Springs", "ispublished": "unpub", "full_text_status": "public", "keywords": "composites, bistability, viscoelasticity, deployable, STEM", "note": "\u00a9 2013 Canadian Association for Composite Structures and Materials.\n\nAccepted Version - PellegrinoICCM2013.pdf
", "abstract": "The effects of stowage on the deployment of composite bistable tape springs are studied. A viscoelastic analytical model is used to predict the relaxation and stability of the structure in its coiled state. The time-dependent stability analysis reveals that the structure remains bistable throughout the relaxation process. A dynamic model is then applied to predict the deployment of the structure once it is released. Experimental deployment results match the deployment predictions within 3% for the case where no stowage is applied. It is shown that stowage causes an increase in the deployment time; in this case, experimental deployment times overshoot those predicted by the model. Secondary effects are observed at high stowage temperatures, which are not predicted by the analytical model. These effects include an abrupt change in the\ndeployment dynamics and a large increase in the deployment time (deployment latency). At higher temperatures still, i.e. for stowage at 100\u00b0C, the structure fails to deploy and becomes stable at all extended lengths.", "date": "2013-08", "date_type": "published", "publisher": "Canadian Association for Composite Structures and Materials", "id_number": "CaltechAUTHORS:20191002-151926429", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191002-151926429", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Hoa-Suong-Van", "name": { "family": "Hoa", "given": "Suong Van" } }, { "id": "Hubert-P", "name": { "family": "Hubert", "given": "Pascal" } } ] }, "primary_object": { "basename": "PellegrinoICCM2013.pdf", "url": "https://authors.library.caltech.edu/records/znww4-fsn43/files/PellegrinoICCM2013.pdf" }, "pub_year": "2013", "author_list": "Brinkmeyer, A.; Pellegrino, S.; et el." }, { "id": "https://authors.library.caltech.edu/records/fx429-jxr87", "eprint_id": 72396, "eprint_status": "archive", "datestamp": "2023-08-19 20:58:15", "lastmod": "2023-10-23 22:30:37", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Paranjape-A-A", "name": { "family": "Paranjape", "given": "Aditya A." }, "orcid": "0000-0002-3164-3215" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Hilton-H-H", "name": { "family": "Hilton", "given": "Harry H." } } ] }, "title": "Optimizing the Forces and Propulsive Efficiency in Bird-Scale Flapping Flight", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2013 AIAA American Institute of Aeronautics and Astronautics. \n\nSupport by the National Science Foundation (IIS-1253758) and the Private Sector Program Division of the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign is gratefully acknowledged.", "abstract": "This paper presents first-principle and numerical studies of flapping flight with the objective of optimizing the force production and propulsive effciency. Strouhal number is identified as a critical parameter affecting all of these variables, and the optimum ranges of Strouhal number are calculated. The results of the calculations, in particular, explain why a value in the range of 0.2-0.4 is usually preferred by nature's flyers. Next, an attempt is made to quantify the effects of wing flexibility on force generation and propulsive efficiency, and it is shown that there exists a critical value of wing elasticity at which propulsive efficiency is maximized, and moreover, this value is driven primarily by the dynamics of the bending\nmotion of the wing rather than twisting.", "date": "2013-08", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics (AIAA)", "id_number": "CaltechAUTHORS:20161129-102652656", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161129-102652656", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "IIS-1253758" }, { "agency": "University of Illinois Urbana-Champaign" } ] }, "other_numbering_system": { "items": [ { "id": "2013-4916", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2013-4916", "pub_year": "2013", "author_list": "Paranjape, Aditya A.; Chung, Soon-Jo; et el." }, { "id": "https://authors.library.caltech.edu/records/4jrqb-vjq70", "eprint_id": 72430, "eprint_status": "archive", "datestamp": "2023-08-19 20:58:30", "lastmod": "2023-10-23 22:33:46", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Yang-Junho", "name": { "family": "Yang", "given": "Junho" } }, { "id": "Dani-Ashwin-P", "name": { "family": "Dani", "given": "Ashwin P." } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Hutchinson-Seth", "name": { "family": "Hutchinson", "given": "Seth" }, "orcid": "0000-0002-3949-6061" } ] }, "title": "Inertial-Aided Vision-Based Localization and Mapping in a Riverine Environment with Reflection Measurements", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2013 American Institute of Aeronautics and Astronautics.\n\nThis material is based in part upon work supported by the Office of Naval Research (N00014-11-1-0088) and John Deere. We would like to thank Xichen Shi, Sunil Patel, Martin Miller, Simon Peter, Ghazaleh Panahandehnigjeh, and Shubham Gupta for their help.", "abstract": "This paper presents an inertial-aided vision-based localization and mapping algorithm for an unmanned aerial vehicle (UAV) that can operate in a GPS-denied riverine environment. We take vision measurements from the features surrounding the river and their corresponding points reflected in the river. We apply a robot-centric mapping framework to let the uncertainty of the features be referenced to the UAV body frame and estimate the 3D positions of point features while estimating the location of the UAV. We demonstrate the localization and mapping results with sensors on our quadcopter UAV platform\nin the University of Illinois at Urbana Champaign Boneyard Creek. The UAV is equipped with a light weight monocular camera, an inertial measurement unit (IMU) which contains\na magnetometer, an ultrasound altimeter, and an on-board computer. To our knowledge, we report the first result of performing localization and mapping by exploiting multiple\nviews with reflections of features in a river-like environment.", "date": "2013-08", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics (AIAA)", "place_of_pub": "Boston MA", "pagerange": "Art. No.-2013", "id_number": "CaltechAUTHORS:20161130-084925184", "isbn": "978-1-62410-224-0", "book_title": "AIAA Guidance, Navigation, and Control Conference 2013", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161130-084925184", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-11-1-0088" } ] }, "other_numbering_system": { "items": [ { "id": "2013-5246", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2013-5246", "pub_year": "2013", "author_list": "Yang, Junho; Dani, Ashwin P.; et el." }, { "id": "https://authors.library.caltech.edu/records/wncdg-75068", "eprint_id": 72422, "eprint_status": "archive", "datestamp": "2023-08-19 20:58:23", "lastmod": "2023-10-23 22:33:14", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Paranjape-A-A", "name": { "family": "Paranjape", "given": "Aditya A." }, "orcid": "0000-0002-3164-3215" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Hutchinson-Seth", "name": { "family": "Hutchinson", "given": "Seth" }, "orcid": "0000-0002-3949-6061" } ] }, "title": "Optimum Spatially Constrained Turns for Agile Micro Aerial Vehicles", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2013 American Institute of Aeronautics and Astronautics.\n\nThis research was funded by the Office of Naval Research (ONR) under Award No. N00014-11-1-0088 and by the National Science Foundation (NSF) under Grant IIS-1253758. The second author was funded through a SMART Scholarship by OSD-T&E (Office of Secretary Defense-Test and Evaluation), Defense - Wide / PE0601120D8Z National Defense Education Program (NDEP) / BA-1, Basic Research.", "abstract": "The objective of this paper is to derive a rapid turn-around maneuver for micro aerial vehicles flying in densely cluttered environments, in the form of variable altitude turns optimized for spatial constraints. The design results in a motion primitive which can be\nimplemented on miniature aircraft at large. The primitive is tested on an MAV equipped with just yaw control and no roll control. The maneuver design not only yields a motion\nprimitive for a turn-around maneuver, but also sheds light on the aircraft design features that enable such a maneuver to be accomplished given some information about the obstacle\nfield.", "date": "2013-08", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "pagerange": "Art. No.-2013", "id_number": "CaltechAUTHORS:20161130-063732477", "isbn": "978-1-62410-224-0", "book_title": "AIAA Guidance, Navigation, and Control Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161130-063732477", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-11-1-0088" }, { "agency": "NSF", "grant_number": "IIS-1253758" }, { "agency": "National Defense Education Program", "grant_number": "PE0601120D8Z" } ] }, "other_numbering_system": { "items": [ { "id": "2013-4941", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2013-4941", "pub_year": "2013", "author_list": "Paranjape, Aditya A.; Chung, Soon-Jo; et el." }, { "id": "https://authors.library.caltech.edu/records/8z4v3-n0b57", "eprint_id": 62102, "eprint_status": "archive", "datestamp": "2023-08-19 20:45:53", "lastmod": "2023-10-25 16:51:15", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ligon-T-C", "name": { "family": "Ligon", "given": "Thomas C." } }, { "id": "Gross-D-J", "name": { "family": "Gross", "given": "David J." } }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "Joseph E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "Response of Piping Tees to Propagating Detonations", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2013 by ASME. \n\nWe acknowledge the very substantial contributions of Dr. Raza Akbar in designing the TS-1 specimen as well as constructing and operating the test facility at Caltech. The work described in this paper was performed in support of the U.S. Department of Energy's (DOE's) Hanford Tank Waste Treatment and Immobilization Plant (WTP) Project (contract number DE-AC27-01RV14136), under subcontract to DOE prime contractor Bechtel National, Inc. \n\nThe United States Government retains, and by accepting the article for publication, the publisher acknowledges that the Unites States Government retains, a non-exclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this work, or allow others to do so, for United States Government purposes.\n\nPublished - PVP2013-97115.pdf
", "abstract": "This paper reports the results of experiments and finite element simulations on the structural response of piping systems to internal detonation loading. Specifically, the work described in this paper focuses on the forces that are produced at tee-junctions that lead to axial and bending structural responses of the piping system.\n\nDetonation experiments were conducted in a 2-in. (50 mm) diameter schedule 40 piping system that was fabricated using 304 stainless steel and welded to ASME B31.3 standards. The 4.1 m (162-in.) long piping system included one tee and was supported using custom brackets and cantilever beams fastened to steel plates that were bolted to the laboratory walls. Nearly-ideal detonations were used in a 30/70 H2-N2O mixture at 1 atm initial pressure and 300 K. Pressure and hoop, axial, and support strains were measured using a high-speed (1 MHz) digital data acquisition system and calibrated signal conditioners.\n\nIt was concluded that detonations propagate through the run of a 90\u00b0 tee with relatively little disturbance in either direction. The detonation load increases by approximately a factor of 2 when the detonation enters through the branch. The deflections of the cantilever beam supports and the hoop and axial pipe strains could be adequately predicted by finite element simulations. The support loads are adequately predicted as long as the supports are constrained to the piping.\n\nThis paper shows that with relatively simple models, quantitative predictions of tee forces can be made for the purposes of design or safety analysis of piping systems subject to internal detonations.", "date": "2013-07-14", "date_type": "published", "publisher": "American Society of Mechanical Engineers", "place_of_pub": "New York, NY", "pagerange": "Art. No. V005T05A018", "id_number": "CaltechAUTHORS:20151113-154527497", "isbn": "978-0-7918-5569-0", "book_title": "ASME 2013 Pressure Vessels and Piping Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151113-154527497", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Department of Energy (DOE)", "grant_number": "DE-AC27-01RV14136" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1115/PVP2013-97115", "primary_object": { "basename": "PVP2013-97115.pdf", "url": "https://authors.library.caltech.edu/records/8z4v3-n0b57/files/PVP2013-97115.pdf" }, "pub_year": "2013", "author_list": "Ligon, Thomas C.; Gross, David J.; et el." }, { "id": "https://authors.library.caltech.edu/records/2w0c6-kpy77", "eprint_id": 62101, "eprint_status": "archive", "datestamp": "2023-08-19 20:45:48", "lastmod": "2023-10-25 16:51:13", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bitter-N-P", "name": { "family": "Bitter", "given": "Neal P." } }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "Joseph E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "On the Adequacy of Shell Models for Predicting Stresses and Strains in Thick-Walled Tubes Subjected to Detonation Loading", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2013 by ASME. \n\nThis work was motivated by findings of the research program carried out for the Hydrogen in Pipes and Ancillary Vessels (HPAV) study for the Hanford Waste Treatment Plant. Greg Jones of the US Department of Energy, Office of River Protection, Hanford WA, was the technical program manager for the portion of the work done at Caltech. The senior author (JES) benefited from discussions on detonation loading of piping with the members of the HPAV team over the period 2005-2012 while he was associated with the HPAV study. In particular, he would like to acknowledge the very substantial contributions to his understanding of the through-wall bending issue by John Minichiello of Bechtel National Inc, as well as Tom Ligon and David Gross of Dominion Engineering. The present work was funded entirely by the California Institute of Technology; we thank the Office of the Provost and the benefactors of the C.L. \"Kelly\" Johnson Professorship.\n\nPublished - PVP2013-97148.pdf
", "abstract": "This paper analyzes the adequacy of shell models for predicting stresses and strains in thick-walled tubes subjected to detonation loads. Of particular interest are the large axial strains which are produced at the inner and outer surfaces of the tube due to bending along the tube axis. First, comparisons between simple shell theory and a static finite element model are used to show that the axial strain varies proportionally with wall thickness and inversely with the square of the axial wavelength. For small wavelengths, this comparison demonstrates nonlinear behavior and a breakdown of the shell model. Second, a dynamic finite element model is used to evaluate the performance of transient shell equations. This comparison is used to quantify the error of the shell model with increasing wall thickness and show that shell models can be inaccurate near the load front where the axial curvature is high. Finally, the results of these analyses are used to show that the large axial strains which are sometimes observed in experiments cannot be attributed to through-wall bending and appear to be caused instead by non-ideal conditions present in the experiments.", "date": "2013-07-14", "date_type": "published", "publisher": "American Society of Mechanical Engineers", "place_of_pub": "New Yoark, NY", "pagerange": "Art. No. V005T05A019", "id_number": "CaltechAUTHORS:20151113-153011013", "isbn": "978-0-7918-5569-0", "book_title": "High-Pressure Technology; ASME NDE Division; Rudy Scavuzzo Student Paper Symposium", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151113-153011013", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1115/PVP2013-97148", "primary_object": { "basename": "PVP2013-97148.pdf", "url": "https://authors.library.caltech.edu/records/2w0c6-kpy77/files/PVP2013-97148.pdf" }, "pub_year": "2013", "author_list": "Bitter, Neal P. and Shepherd, Joseph E." }, { "id": "https://authors.library.caltech.edu/records/3tzdj-7pe12", "eprint_id": 98079, "eprint_status": "archive", "datestamp": "2023-08-19 20:28:33", "lastmod": "2023-10-18 17:01:36", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ferrero-P", "name": { "family": "Ferrero", "given": "Pietro" } }, { "id": "Kartha-A", "name": { "family": "Kartha", "given": "Anand" } }, { "id": "Subbareddy-P-K", "name": { "family": "Subbareddy", "given": "Pramod K." } }, { "id": "Candler-G-V", "name": { "family": "Candler", "given": "Graham V." } }, { "id": "Dimotakis-P-E", "name": { "family": "Dimotakis", "given": "Paul E." } } ] }, "title": "LES of a high-Reynolds number, chemically reacting mixing layer", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2013 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 22 Jun 2013.", "abstract": "In this work we perform large eddy simulations of high-Reynolds number, chemically reacting, spatially developing mixing layers with the goal of reproducing the experimental results obtained by Slessor at al. The chemical mechanism is the reaction of hydrogen and fluorine to produce HF. This is an exothermic, kinetically-fast reaction (Da \u00bb 1) in which the heat release (and the consequent temperature rise) is a direct measure of the product formation. The upper stream has a velocity of U_1 = 100 m/s and it is composed of\na mixture of H_2 and inert gases, while the bottom stream has a lower velocity, U_2 = 40 m/s, and carries F_2 diluted in inert gases. Both streams have the same density. The mixing layer develops from a splitter plate and is characterized by a fairly large Reynolds number (Re_(\u03b4T) = 2\u00b710^5 ). Although we do not explicitly model the boundary layers developing on the splitter plate, we impose laminar boundary-layer profiles at the inflow consistent with those reported in Slessor et al. The three-dimensional simulations show an excellent agreement with the experiments for the mean velocity, although some discrepancies are found in the temperature/product formation profiles. LES results tend to overestimate the molecular mixing in the flow: In the very high Damk\u00f6hler regime this results In an overprediction of product formation and temperature rise. We study these issues by conducting some two-dimensional simulations using the Filtered Mass Density Function methodology which alleviates this problem. We compute the probability density functions of the mixture fraction as a function of the transverse coordinate and we confirm that the most probable mixture fraction in the layer is the one predicted by the asymmetric entrainment ratio\nmodel. In particular, about ~30% more mass is entrained into the layer from the high-speed stream as compared to the lower stream.", "date": "2013-06-22", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2013-3185", "id_number": "CaltechAUTHORS:20190821-111717433", "isbn": "978-1-62410-214-1", "book_title": "43rd Fluid Dynamics Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190821-111717433", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2013-3185", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2013-3185", "pub_year": "2013", "author_list": "Ferrero, Pietro; Kartha, Anand; et el." }, { "id": "https://authors.library.caltech.edu/records/npvvr-t0q57", "eprint_id": 98076, "eprint_status": "archive", "datestamp": "2023-08-19 20:28:29", "lastmod": "2023-10-18 17:01:25", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Cymbalist-N", "name": { "family": "Cymbalist", "given": "Niccolo" } }, { "id": "Dimotakis-P-E", "name": { "family": "Dimotakis", "given": "Paul E." } } ] }, "title": "A parametric study of ethylene-fueled scramjet combustion", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2013 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 22 Jun 2013.", "abstract": "Ignition-delay distances for ethylene fuel injected into a supersonic combustor are modeled for jet-in-crossflow and shear-layer fuel-injection schemes using analytical models for entrainment and mixing, coupled with detailed chemical-kinetics simulations. Ignition delay distances are calculated for a two-dimensional parameter space of assumed vehicle flight Mach number and fuel-preheat stagnation temperature. The sensitivity of the ignition delays to these parameters is compared and discussed for the two fuel-injection schemes.", "date": "2013-06-22", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2013-2978", "id_number": "CaltechAUTHORS:20190821-105102833", "isbn": "978-1-62410-214-1", "book_title": "43rd Fluid Dynamics Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190821-105102833", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2013-2978", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2013-2978", "pub_year": "2013", "author_list": "Cymbalist, Niccolo and Dimotakis, Paul E." }, { "id": "https://authors.library.caltech.edu/records/dz0c0-dg293", "eprint_id": 40936, "eprint_status": "archive", "datestamp": "2023-08-19 20:26:36", "lastmod": "2023-10-24 23:18:55", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Aria-A-I", "name": { "family": "Aria", "given": "Adrianus I." } }, { "id": "Guittet-M", "name": { "family": "Guittet", "given": "M\u00e9lanie" } }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "Morteza" } } ] }, "title": "Use of Vertically Aligned Carbon Nanotubes for Electrochemical Double-Layer Capacitors", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2013 by Taylor & Francis Group, LLC.\nThis work was supported by The Office of Naval Research under Grant number N00014-11-1-0031\nand The Fletcher-Jones Foundation under Grant number 9900600. The authors gratefully acknowledge\nsupport and infrastructure provided for this work by the Charyk Laboratory for Bioinspired\nDesign, the Kavli Nanoscience Institute (KNI), and the Molecular Materials Research Center\n(MMRC) at the California Institute of Technology.", "abstract": "The demand for, and consumption of, global energy is continually increasing across a world whose\npopulation will grow to nearly 9 billion people in the next couple of years. It is poised to continue\nits steady increase in the next several decades. The climate change and the decreasing availability of\nfossil fuels have hastened the development of satisfying sustainable and renewable energy technologies.\nSince electrical energy storage systems such as batteries and capacitors are considered as the\nmost critical link between the ever-increasing renewable energy supply and demand, a lot of work\nhas been done to improve their efficiency and performance. Further, the advancement of micro/\nnano-electro-mechanical devices for telecommunication and biomedical applications initiates the\ndemand for reliable lightweight electrical energy storage systems with small form factors. To fulfill\n\nall these requirements, the development of new materials with an exceptional specific surface area\nand excellent electrochemical properties has become the focus of much research effort.\nElectrical energy can be stored either chemically, for example, batteries, or physically, for example,\ncapacitors. Chemically, the electrical energy is converted into chemical energy via Faradaic\nreduction and oxidation (redox) reactions. Although the energy conversion from electrical to chemical\nand vice versa is thermodynamically reversible in principle, in practice, such conversion often\ninvolves some degree of irreversibility due to the electrode\u2212electrolyte interphase changes during\nthe charging and discharging processes [1]. Therefore, the charge/discharge rates of batteries are\nvery low and their lifecycle is limited to only several thousand cycles. However, depending on the\ntypes of batteries, they can have a very high gravimetric energy density of up to 200 Wh/kg [2].", "date": "2013-06-17", "date_type": "published", "publisher": "CRC Press", "place_of_pub": "Hoboken, NJ", "pagerange": "445-456", "id_number": "CaltechAUTHORS:20130826-145146675", "isbn": "9781466565241", "book_title": "Nanoelectronic Device Applications Handbook", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130826-145146675", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-11-1-0031" }, { "agency": "Fletcher-Jones Foundation", "grant_number": "9900600" } ] }, "local_group": { "items": [ { "id": "Kavli-Nanoscience-Institute" }, { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Morris-J-E", "name": { "family": "Morris", "given": "James E." } }, { "id": "Iniewski-K", "name": { "family": "Iniewski", "given": "Krzysztof" } } ] }, "pub_year": "2013", "author_list": "Aria, Adrianus I.; Guittet, M\u00e9lanie; et el." }, { "id": "https://authors.library.caltech.edu/records/925gf-yv960", "eprint_id": 49998, "eprint_status": "archive", "datestamp": "2023-08-19 20:16:47", "lastmod": "2023-10-17 22:25:54", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Patil-V-N", "name": { "family": "Patil", "given": "V. N." } }, { "id": "Levin-D-A", "name": { "family": "Levin", "given": "D. A." } }, { "id": "Gimelshein-S-G", "name": { "family": "Gimelshein", "given": "S. G." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "J. M." }, "orcid": "0000-0003-3129-5035" } ] }, "title": "Study of shock-shock interactions for the HET facility\n double wedge configuration using the DSMC approach", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2013 by the American Institute of Aeronautics and Astronautics, Inc.\n\nAIAA 2013-3202.\n\nThe research performed at the Pennsylvania State University was supported by the Air Force Office of\nScientific Research through AFOSR Grant No. FA9550-11-1-0129 with a subcontract award number 2010-06171-01 to PSU. We would like to acknowledge Prof. M. Ivanov of the Institute of Theoretical and Applied\nMechanics, Russia for the use of the original SMILE code.", "abstract": "A set of numerical simulations designed to study the laminar, shock-shock interactions\nfrom hypersonic flows about a double-wedge configuration for the Hypervelocity Expansion\nTube (HET) facility are presented. Computations are made using the Direct Simulation\nMonte Carlo (DSMC) method, an approach for modeling finite-Knudsen number\nflows. The current study focuses on the investigation of Mach 7 nitrogen flows about a\n30-/55-deg double wedge model for stagnation enthalpies varying from 2.0-8.0 MJ/kg. The\nsimulation results of the double wedge flows are compared with the data obtained from\nexperiments at HET. Numerical Schlierens are generated to visualize the shock structure\nand shock-shock interactions present in these flows and are compared with the experimental\nSchlieren images. The computed heat transfer values from the simulations match the\nexperiment along the first surface, but on the second wedge the computed heat transfer distribution over predicts the measured peak values. The influence of different models\nfor nonequilibrium nitrogen dissociation, rotational and vibrational relaxation rates, and\ngas-surface interactions on the shock interaction region are analyzed for high enthalpy flow\nfeatures and heat transfer rates. Overall good agreement is observed in the experimental\nand computational results. Unsteadiness of the flow and time-averaging of the experimental\nmeasurements are likely reasons for the inability of the DSMC simulations to exactly\nreproduce the experimental data.", "date": "2013-06", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Red Hook, NY", "id_number": "CaltechAUTHORS:20140924-131045732", "isbn": "9781627488914", "book_title": "43rd AIAA fluid dynamics conference and exhibit 2013", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140924-131045732", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-11-1-0129" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2013-3202", "pub_year": "2013", "author_list": "Patil, V. N.; Levin, D. A.; et el." }, { "id": "https://authors.library.caltech.edu/records/emdt5-kcg02", "eprint_id": 45852, "eprint_status": "archive", "datestamp": "2023-08-19 20:14:59", "lastmod": "2023-10-26 18:29:55", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Liu-Yang", "name": { "family": "Liu", "given": "Yang" }, "orcid": "0000-0002-8155-9134" }, { "id": "Park-Jungwook", "name": { "family": "Park", "given": "Jungwook" } }, { "id": "Lang-R-J", "name": { "family": "Lang", "given": "Robert J." } }, { "id": "Emami-A", "name": { "family": "Emami-Neyestanak", "given": "Azita" }, "orcid": "0000-0002-6945-9958" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" }, { "id": "Humayun-M-S", "name": { "family": "Humayun", "given": "Mark S." }, "orcid": "0000-0002-5830-5208" }, { "id": "Tai-Yu-Chong", "name": { "family": "Tai", "given": "Yu-Chong" }, "orcid": "0000-0001-8529-106X" } ] }, "title": "Parylene origami structure for intraocular implantation", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Origami, parylene-C, intraocular implantation", "note": "\u00a9 2013 IEEE. The authors would like to thank all the group members in the Caltech MEMS and Micromachining lab for help and discussion. We thank Mr. Trevor Roper especially for his guidance and maintenance on equipment in the lab. We also thank Lee L. Wilson from Dr. Sergio's group and Matthew Loh from Dr. Azita's group.", "abstract": "This paper presents the use of origami technique to construct a 3D spherical structure from a 2D parylene-C (PA-C) film with designed folding crease patterns. This origami technique is developed or intended for intraocular epiretinal implant application, which requires a \"curved\" electrode array to match the curvature of the macula. The folding method and process are described here using silicone oil as a temporary glue to hold the folded structures through meniscus force. The temporary origami is then thermally set into permanent 3D shapes at 100 \u00b0C for 30 minutes in vacuum utilizing parylene-C's viscoelastic properties. The reported origami technique enables the possibility of first making an extended device in 2D format and, after a possible minimal surgical cut and insertion, then folding it into a 3D device inside the eye for necessary geometric matching with host tissues.", "date": "2013-06", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "1549-1552", "id_number": "CaltechAUTHORS:20140520-140334969", "isbn": "9781467359818", "book_title": "2013 Transducers & Eurosensors XXVII", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140520-140334969", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/Transducers.2013.6627077", "pub_year": "2013", "author_list": "Liu, Yang; Park, Jungwook; et el." }, { "id": "https://authors.library.caltech.edu/records/dwvtb-n4659", "eprint_id": 87983, "eprint_status": "archive", "datestamp": "2023-08-19 19:58:58", "lastmod": "2024-01-14 20:28:18", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "MacEwen-H-A", "name": { "family": "MacEwen", "given": "Howard A." } }, { "id": "Breckinridge-J-B", "name": { "family": "Breckinridge", "given": "James B." }, "orcid": "0000-0002-9488-098X" } ] }, "title": "Large diffractive/refractive apertures for space and airborne telescopes", "ispublished": "unpub", "full_text_status": "public", "keywords": "Diffractive optics, refractive optics, membrane aperture, airborne telescope, space telescope", "note": "\u00a9 2013 Society of Photo-Optical Instrumentation Engineers (SPIE).\n\nPublished - 873904.pdf
", "abstract": "Recent work, specifically the Lawrence Livermore National Laboratory (LLNL) Eyeglass and the DARPA MOIRE programs, have evaluated lightweight, easily packaged and deployed, diffractive/refractive membrane transmissive lenses as entrance apertures for large space and airborne telescopes. This presentation describes a new, innovative approach to the theory of diffractive and refractive effects in lenses used as telescope entrance apertures and the fabrication of the necessary large membrane optics. Analyses are presented to indicate how a broadband, highly transmissive diffractive / refractive membrane lens can be developed and fabricated, and potential applications in defense and astronomy are briefly discussed.", "date": "2013-05-21", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "Art. No. 873904", "id_number": "CaltechAUTHORS:20180718-162409515", "isbn": "9780819495303", "book_title": "Sensors and Systems for Space Applications VI", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180718-162409515", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Pham-Khanh-D", "name": { "family": "Pham", "given": "Khanh D." } }, { "id": "Cox-J-L", "name": { "family": "Cox", "given": "Joseph L." } }, { "id": "Howard-R-T", "name": { "family": "Howard", "given": "Richard T." } }, { "id": "Chen-Genshe", "name": { "family": "Chen", "given": "Genshe" } } ] }, "doi": "10.1117/12.2015457", "primary_object": { "basename": "873904.pdf", "url": "https://authors.library.caltech.edu/records/dwvtb-n4659/files/873904.pdf" }, "pub_year": "2013", "author_list": "MacEwen, Howard A. and Breckinridge, James B." }, { "id": "https://authors.library.caltech.edu/records/047ex-0ap32", "eprint_id": 59899, "eprint_status": "archive", "datestamp": "2023-08-19 19:48:44", "lastmod": "2023-10-23 22:48:45", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "M\u00e9vel-R", "name": { "family": "M\u00e9vel", "given": "R." }, "orcid": "0000-0002-0032-350X" }, { "id": "Chatelain-K", "name": { "family": "Chatelain", "given": "K." } }, { "id": "Boettcher-P-A", "name": { "family": "Boettcher", "given": "P. A." } }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "J. E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "Low Temperature Oxidation of n-Hexane in a Flow Reactor", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2013 Curran Associates, Inc. \n\nPaper # 070RK-0399.\n\nThe present work was carried out in the Explosion Dynamics Laboratory of the California Institute of Technology and was supported by The Boeing Company through a Strategic Research and Development Relationship Agreement CT-BA-GTA-1 with Ivana Jojic as technical monitor. The authors are gratefull to Professor G. Dayma, ICARE- CNRS/Universit\u00e9 d'Orl\u00e9ans, for providing the updated version of the detailed reaction model.", "abstract": "The risk of igniting a flammable mixture in fuel tank vapor space is a major concern in aviation safety.\nIn order to analyze the hazards and develop mitigation strategies, it is necessary to characterize the\nexplosive properties of kerosene vapor-air mixtures over a wide ranges of initial conditions. n-Hexane\nhas been extensively used in our laboratory as a single component surrogate of kerosene. In the present\nstudy, hexane oxidation by oxygen was studied in a flow reactor at equivalence ratios of 0.7, 1 and 1.5\nfor mixtures diluted at 90% with nitrogen. Residence time was set-up at 2 s and the pressure at 100\nkPa. The evolution of the gas phase composition at the reactor exit was studied over the range 450-1000\nK. Laser-based diagnostics and gas chromatography analysis were used to characterize the exit mixture\ncomposition. The chemical species measurements revleaved three distinct regimes of oxidation, namely\n(i) the cool flame region from 600 to 650 K, (ii) the NTC region between 675 and 775 K, and (iii) the\nhigh temperature oxidation regime from 800 K. The modeling study demonstrated the capability of\nreproducing most of the trends observed experimentally.", "date": "2013-05", "date_type": "published", "publisher": "Curran Associates, Inc.", "place_of_pub": "Red Hook, NY", "pagerange": "1-17", "id_number": "CaltechAUTHORS:20150826-092211579", "isbn": "9781627488426", "book_title": "8th US National Combustion Meeting", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150826-092211579", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Boeing Company Strategic Research and Development Relationship", "grant_number": "CT-BA-GTA-1" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "pub_year": "2013", "author_list": "M\u00e9vel, R.; Chatelain, K.; et el." }, { "id": "https://authors.library.caltech.edu/records/8yb2j-y6136", "eprint_id": 50157, "eprint_status": "archive", "datestamp": "2023-08-19 19:48:12", "lastmod": "2023-10-17 22:48:35", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Coronel-S-A", "name": { "family": "Coronel", "given": "S." }, "orcid": "0000-0002-7088-7976" }, { "id": "M\u00e9vel-R", "name": { "family": "M\u00e9vel", "given": "R." }, "orcid": "0000-0002-0032-350X" }, { "id": "Vervish-P", "name": { "family": "Vervish", "given": "P." } }, { "id": "Boettcher-P-A", "name": { "family": "Boettcher", "given": "P. A." } }, { "id": "Thomas-V", "name": { "family": "Thomas", "given": "V." } }, { "id": "Chaumeix-N", "name": { "family": "Chaumeix", "given": "N." } }, { "id": "Darabiha-N", "name": { "family": "Darabiha", "given": "N." } }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "J. E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "Laminar Burning Speed of n-Hexane-Air Mixtures", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2013 Curran Associates, Inc.\n\nPaper # 070LT-0383.\n\nThe authors would like to thank Professor Guillaume Blanquart from Caltech for generously providing\nus with the Caltech reaction model. The present work was carried out in the Explosion\nDynamics Laboratory of the California Institute of Technology and was supported by The Boeing\nCompany through a Strategic Research and Development Relationship Agreement CT-BA-GTA-1.", "abstract": "n-Hexane is an easy-to-use fuel for laboratory investigations of hydrocarbon vapor explosions and has\nbeen used widely as a surrogate for commodity fuels such as kerosene. As part of our ongoing studies\ninto flammability hazards in aircraft environments, we have been carrying out experiments at reduced\npressure, below 100 kPa, in order to measure ignition and flame propagation in n-hexane-air mixtures.\nThe objectives of the present study were to study experimentally the effects of composition, initial temperature,\nand initial pressure on the burning speed of n-hexane-air mixtures. Our study expands on and\ncomplements existing data and compares the experimental measurements with numerical predictions\nfrom various chemical models. The laminar burning speed of n-hexane-air mixtures was measured experimentally\nusing the spherically expanding flame technique. The effects of equivalence ratio, initial\ntemperature and initial pressure were investigated in the ranges: \u03a6 = 0.75\u20131.7, T_1 = 295\u2013380 K and P_1\n= 40\u2013100 kPa, respectively. A typical inverted U-shaped curve was obtained for the evolution of the\nburning speed as a function of equivalence ratio. At a fixed composition, the burning speed increases as\nthe initial temperature increases and as the initial pressure decreases; this is in agreement with previous\nburning speed studies done using n-alkanes, from C_5 to C_8. Three detailed reaction models, the JetSurF\nmodel, the model of Ramirez et al., and the Caltech model were evaluated with respect to the present\ndata. The present study indicated that among the models tested, the JetSurF model is the most accurate\nmodel for evaluating n-hexane-air mixtures.", "date": "2013-05", "date_type": "published", "publisher": "Curran Associates, Inc.", "place_of_pub": "Red Hook, NY", "pagerange": "2568-2583", "id_number": "CaltechAUTHORS:20141001-153425836", "isbn": "9781627488426", "book_title": "8th US national combustion meeting 2013 : Park City, Utah, USA, 19-22 May 2013.", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141001-153425836", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Boeing Company Strategic Research and Development Relationship", "grant_number": "CT-BA-GTA-1" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "pub_year": "2013", "author_list": "Coronel, S.; M\u00e9vel, R.; et el." }, { "id": "https://authors.library.caltech.edu/records/4j0yh-wfp59", "eprint_id": 97968, "eprint_status": "archive", "datestamp": "2023-08-19 19:31:22", "lastmod": "2023-10-18 16:55:30", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Steeves-J", "name": { "family": "Steeves", "given": "John" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Ultra-Thin Highly Deformable Composite Mirrors", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2013 American Institute of Aeronautics and Astronautics. \n\nWe thank Gilles Rocher and Thomas Ricard (North Thin-Ply Technologies) for providing materials for this research and Professor Paolo Ermanni (ETH Zurich) for advice on actuator concepts and development. We also thank Keith Patterson (Caltech) for advice regarding the fabrication processes. Financial support has been provided by the Dow Resnick Bridge program at Caltech and the Natural Sciences and Engineering Research Council of Canada.", "abstract": "Optical quality mirrors are heavy, expensive and difficult to manufacture. This paper presents a novel mirror concept based on an active laminate consisting of an ultra-thin carbon-fiber shell bonded to a piezo-ceramic active layer coated with patterned electrodes. Mirrors based on this concept are less than 1 mm thick and hence are very lightweight and flexible. They also have a large dynamic range of actuation that allows them to take up a wide range of deformed configurations. This concept is compatible with relatively high-volume manufacturing processes and can potentially achieve a significant reduction in cost in comparison to currently available active mirrors. It is also suitable for applications ranging from concentrators for solar power generation to primary mirrors for optical telescopes. The paper presents an overview of the mirror components as well as a simple design relationship for sizing the active layer. The expected performance of a preliminary design for a 1 m diameter mirror with a radius of curvature of 15 m is computed numerically, showing that a set of 96 actuators can remove an edge-to-edge manufacturing-induced cylindrical curvature of 5 mm to an RMS accuracy of 50 \u03bcm. The prescription of the mirror can also be adjusted to a radius of curvature of 11 m with an accuracy of 160 \u03bcm. The development and characterization of a proof-of-concept prototype mirror is also presented.", "date": "2013-04-08", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2013-1523", "id_number": "CaltechAUTHORS:20190816-144340709", "isbn": "9781624102233", "book_title": "54th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190816-144340709", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Dow Resnick Bridge Program" }, { "agency": "Natural Sciences and Engineering Research Council of Canada (NSERC)" } ] }, "other_numbering_system": { "items": [ { "id": "2013-1523", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2013-1523", "pub_year": "2013", "author_list": "Steeves, John and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/mxbf0-3md88", "eprint_id": 98223, "eprint_status": "archive", "datestamp": "2023-08-19 19:31:34", "lastmod": "2023-10-18 17:09:55", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ning-Xin", "name": { "family": "Ning", "given": "Xin" }, "orcid": "0000-0002-9432-3665" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Design and testing of imperfection-insensitive monocoque cylindrical shells", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2013 American Institute of Aeronautics and Astronautics.", "abstract": "The high efficiency of monocoque cylindrical shells in carrying axial loads is curtailed by their extreme sensitivity to imperfections. For practical applications, this issue has been alleviated by introducing closely stiffened shells which, however, require expensive manufacturing. Here we present an alternative approach that provides a fundamentally different solution. We design symmetry-breaking wavy cylindrical shells that avoid imperfection sensitivity. Their cross-section is formulated by NURBS interpolation on control points whose positions are optimized by evolutionary algorithms. We have applied our approach to both isotropic and orthotropic shells and have also constructed optimized composite wavy shells and measured their imperfections and experimental buckling loads. Through these experiments we have confirmed that optimally designed wavy shells are imperfection-insensitive. We have studied the mass efficiency of these new shells and found them to be more efficient than even a perfect circular cylindrical shell and most stiffened cylindrical shells.", "date": "2013-04-08", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2013-1768", "id_number": "CaltechAUTHORS:20190826-092412987", "isbn": "9781624102233", "book_title": "54th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190826-092412987", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2013-1768", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2013-1768", "pub_year": "2013", "author_list": "Ning, Xin and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/8bxnc-twh41", "eprint_id": 97969, "eprint_status": "archive", "datestamp": "2023-08-19 19:31:30", "lastmod": "2023-10-18 16:55:33", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Wilson-Lee-L", "name": { "family": "Wilson", "given": "Lee" }, "orcid": "0000-0002-5865-9903" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" }, { "id": "Danner-R", "name": { "family": "Danner", "given": "Rolf" } } ] }, "title": "Origami Sunshield Concepts for Space Telescopes", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2013 American Institute of Aeronautics and Astronautics.", "abstract": "This paper presents two origami inspired concepts for sunshields for a deployable X-ray space telescope. Analytical models of the fold layout and sunshield deployment have been derived, and these models have been used to match the sunshield design to a set of geometric constraints. To validate the design, a proof-of-concept physical model of the optimized analytical design was constructed at 1:10 scale.", "date": "2013-04-08", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2013-1594", "id_number": "CaltechAUTHORS:20190816-144340816", "isbn": "9781624102233", "book_title": "54th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190816-144340816", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2013-1594", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2013-1594", "pub_year": "2013", "author_list": "Wilson, Lee; Pellegrino, Sergio; et el." }, { "id": "https://authors.library.caltech.edu/records/45wtc-6tz14", "eprint_id": 42601, "eprint_status": "archive", "datestamp": "2023-08-19 19:26:01", "lastmod": "2023-10-25 16:56:01", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Olson-G-M", "name": { "family": "Olson", "given": "Gina M." } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" }, { "id": "Banik-J", "name": { "family": "Banik", "given": "Jeremy" } }, { "id": "Constantine-J", "name": { "family": "Constantine", "given": "Joseph" } } ] }, "title": "Deployable Helical Antennas for CubeSats", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2013 American Institute of Aeronautics and Astronautics. \n\nSupport from the Air Force Research Laboratory Summer Space Scholars Program and AFOSR (award no. FA9550-13-1-0061, program manager Dr David Stargel) is gratefully acknowledged.\n\nAccepted Version - DeployableHelicalAntennaforCubeSatsFinal.pdf
", "abstract": "This paper explores the behavior of a self-deploying helical pantograph antenna for CubeSats. The helical pantograph concept is described along with concepts for attachment to the satellite bus. Finite element folding simulations of a pantograph consisting of eight helices are presented and compared to compaction force experiments done on a prototype antenna. Reflection coefficient test are also presented, demonstrating the operating frequency range of the prototype antenna. The helical pantograph is shown to be a promising alternative to current small satellite antenna solutions.", "date": "2013-04", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 1671", "id_number": "CaltechAUTHORS:20131120-152814552", "isbn": "978-1-62410-223-3", "book_title": "54th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131120-152814552", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Research Laboratory (AFRL)" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-13-1-0061" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2013-1671", "primary_object": { "basename": "DeployableHelicalAntennaforCubeSatsFinal.pdf", "url": "https://authors.library.caltech.edu/records/45wtc-6tz14/files/DeployableHelicalAntennaforCubeSatsFinal.pdf" }, "pub_year": "2013", "author_list": "Olson, Gina M.; Pellegrino, Sergio; et el." }, { "id": "https://authors.library.caltech.edu/records/f311v-tpx84", "eprint_id": 73120, "eprint_status": "archive", "datestamp": "2023-08-19 14:35:37", "lastmod": "2024-01-13 20:22:24", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Morgan-Daniel", "name": { "family": "Morgan", "given": "Daniel" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Hadaegh-F-Y", "name": { "family": "Hadaegh", "given": "Fred Y." } } ] }, "title": "Decentralized Model Predictive Control of Swarms of Spacecraft Using Sequential Convex Programming", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2013 American Institute of Aeronautics and Astronautics.\n\nThis research was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. \u00a9 California Institute of Technology. This work was supported by a NASA Office of the Chief Technologists Space Technology Research Fellowship. Government sponsorship acknowledged.\n\nAccepted Version - Morgan_AAS_13_439.pdf
", "abstract": "This paper presents a decentralized, model predictive control algorithm for the reconfiguration of swarms of spacecraft composed of hundreds to thousands of agents with limited capabilities. In our prior work, sequential convex programming has been used to determine collision-free, fuel-efficient trajectories for the reconfiguration of spacecraft swarms. This paper uses a model predictive control approach to implement the sequential convex programming algorithm in real-time. By updating the optimal trajectories during the reconfiguration, the model predictive control algorithm results in decentralized computations and communication between neighboring spacecraft only. Additionally, model predictive control reduces the horizon of the convex optimizations, which reduces the run time of the algorithm.", "date": "2013-02", "date_type": "published", "publisher": "Univelt Inc.", "pagerange": "1-20", "id_number": "CaltechAUTHORS:20161222-070302558", "isbn": "978-0-87703-597-8", "book_title": "Spaceflight mechanics meeting, 2013", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161222-070302558", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "primary_object": { "basename": "Morgan_AAS_13_439.pdf", "url": "https://authors.library.caltech.edu/records/f311v-tpx84/files/Morgan_AAS_13_439.pdf" }, "pub_year": "2013", "author_list": "Morgan, Daniel; Chung, Soon-Jo; et el." }, { "id": "https://authors.library.caltech.edu/records/dmaf5-ckz81", "eprint_id": 98208, "eprint_status": "archive", "datestamp": "2023-08-19 14:19:02", "lastmod": "2023-10-18 17:09:13", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Seele-R", "name": { "family": "Seele", "given": "Roman" } }, { "id": "Graff-E-C", "name": { "family": "Graff", "given": "Emilio" } }, { "id": "Lin-John-C", "name": { "family": "Lin", "given": "John" }, "orcid": "0000-0003-2794-184X" }, { "id": "Wygnanski-I-J", "name": { "family": "Wygnanski", "given": "Israel" } } ] }, "title": "Performance Enhancement of a Vertical Tail Model with Sweeping Jet Actuators", "ispublished": "unpub", "full_text_status": "public", "note": "This material is declared a work of the U.S. Government and is not subject to copyright protection in the United States. \n\nThis research was supported by the National Aeronautics and Space Administration (NASA) under the Environmentally Responsible Aviation (ERA) Project. The research was funded through NASA Technology, Engineering, and Aerospace Mission Support (TEAMS) Contract Task Order 097D3-NNL10AM26T.\n\nPublished - 20130003329.pdf
", "abstract": "Active Flow Control (AFC) experiments performed at the Caltech Lucas Adaptive Wall Wind Tunnel on a 12%-thick, generic vertical tail model indicated that sweeping jets emanating from the trailing edge (TE) of the vertical stabilizer significantly increased the side force coefficient for a wide range of rudder deflection angles and yaw angles at free-stream velocities approaching takeoff rotation speed. The results indicated that 2% blowing momentum coefficient (C_\u03bc) increased the side force in excess of 50% at the maximum conventional rudder deflection angle in the absence of yaw. Even C_\u03bc = 0.5% increased the side force in excess of 20% under these conditions. This effort was sponsored by the NASA Environmentally Responsible Aviation (ERA) project and the successful demonstration of this flow-control application could have far reaching implications. It could lead to effective applications of AFC technologies on key aircraft control surfaces and lift enhancing devices (flaps) that would aid in reduction of fuel consumption through a decrease in size and weight of wings and control surfaces or a reduction of the noise footprint due to steeper climb and descent.", "date": "2013-01-07", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2013-0411", "id_number": "CaltechAUTHORS:20190826-092411552", "isbn": "9781624101816", "book_title": "51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190826-092411552", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA", "grant_number": "097D3-NNL10AM26T" } ] }, "other_numbering_system": { "items": [ { "id": "2013-0411", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2013-411", "primary_object": { "basename": "20130003329.pdf", "url": "https://authors.library.caltech.edu/records/dmaf5-ckz81/files/20130003329.pdf" }, "pub_year": "2013", "author_list": "Seele, Roman; Graff, Emilio; et el." }, { "id": "https://authors.library.caltech.edu/records/cjgwj-gp004", "eprint_id": 98210, "eprint_status": "archive", "datestamp": "2023-08-19 14:19:12", "lastmod": "2023-10-18 17:09:19", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Jewell-J-S", "name": { "family": "Jewell", "given": "Joseph S." }, "orcid": "0000-0002-4047-9998" }, { "id": "Wagnild-R-M", "name": { "family": "Wagnild", "given": "Ross M." } }, { "id": "Leyva-I-A", "name": { "family": "Leyva", "given": "Ivett A." } }, { "id": "Candler-G-V", "name": { "family": "Candler", "given": "Graham V." } }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "Joseph E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "Transition Within a Hypervelocity Boundary Layer on a 5-Degree Half-Angle Cone in Air/CO_2 Mixtures", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2013 by the California Institute of Tehcnology. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission. \n\nThe authors thank Mr. Nick Parziale for his assistance in running T5, Mr. Bahram Valiferdowsi for his work with design, fabrication, and maintenance, and Prof. Hans Hornung for his advice and support. The experimental portion of this project was sponsored by the Air Force Office of Scientific Research under award number FA9550-10-1-0491 and the NASA/AFOSR National Center for Hypersonic Research. The computational work was sponsored by the Air Force Office of Scientific Research grant FA9550-10-1-0352. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. The views expressed herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of AFOSR, Sandia, or the U.S. Government.\n\nAccepted Version - aiaa2013-ASM-Jewell.pdf
", "abstract": "Laminar to turbulent transition on a smooth 5-degree half angle cone at zero angle of attack is investigated computationally and experimentally in hypervelocity flows of air, carbon dioxide, and a mixture of 50% air and carbon dioxide by mass. Transition N factors above 10 are observed for air flows. At comparable reservoir enthalpy and pressure, flows containing carbon dioxide are found to transition up to 30% further downstream on the cone than flows in pure air in terms of x-displacement, and up to 38% and 140%, respectively, in terms of the Reynolds numbers calculated at edge and reference conditions.", "date": "2013-01-07", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2013-0523", "id_number": "CaltechAUTHORS:20190826-092411748", "isbn": "9781624101816", "book_title": "51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190826-092411748", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-10-1-0491" }, { "agency": "NASA" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-10-1-0352" }, { "agency": "Department of Energy (DOE)", "grant_number": "DE-AC04-94AL85000" } ] }, "other_numbering_system": { "items": [ { "id": "2013-0523", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2013-523", "primary_object": { "basename": "aiaa2013-ASM-Jewell.pdf", "url": "https://authors.library.caltech.edu/records/cjgwj-gp004/files/aiaa2013-ASM-Jewell.pdf" }, "pub_year": "2013", "author_list": "Jewell, Joseph S.; Wagnild, Ross M.; et el." }, { "id": "https://authors.library.caltech.edu/records/w8186-j9128", "eprint_id": 98209, "eprint_status": "archive", "datestamp": "2023-08-19 14:19:07", "lastmod": "2023-10-18 17:09:16", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Parziale-N-J", "name": { "family": "Parziale", "given": "N. J." }, "orcid": "0000-0001-9880-1727" }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "J. E." }, "orcid": "0000-0003-3181-9310" }, { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "H. G." }, "orcid": "0000-0002-4903-8419" } ] }, "title": "Differential Interferometric Measurement of Instability at Two Points in a Hypervelocity Boundary Layer", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2013 American Institute of Aeronautics and Astronautics. \n\nThanks to Bahram Valiferdowsi of GALCIT for the isometric views of the solid model of the facility, and helping run it. Special thanks to Dr. Ross Wagnild of Sandia National Laboratories for performing the grid generation and general help with the computations. Thanks to Jason Damazo of GALCIT for his helpful discussions on high-speed imaging. Also, thanks to Joe Jewell for instrumenting the cone with high-speed thermocouples. This work was sponsored by AFOSR/National Center for Hypersonic Research in Laminar-Turbulent Transition, for which Dr. John Schmisseur and Dr. Deepak Bose are the program managers. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the Air Force Office of Scientific Research or the U.S. Government.\n\nAccepted Version - 2013_AIAA_Differential_Interferometric_Measurement_of_Instability_at_Two_Points_in_a_Hypervelocity_Boundary_Layer.pdf
", "abstract": "The focused laser differential interferometer (FLDI) was used to investigate disturbances in a hypervelocity boundary layer on a sharp five degree half-angle cone. The T5 hypervelocity free-piston driven reflected-shock tunnel was used as the test facility; in such a facility the study of thermo-chemical/fluid-dynamic energy exchange is emphasized. Two sensitive FLDI probe volumes were aligned along a generator of the cone that recorded time-traces of density fluctuation at sufficient time resolution, spatial resolution, and signal to noise ratio, so that the boundary layer instability could be resolved. This arrangement of the FLDI allows for the interpretation of disturbances at two points and the correlation between them. The acoustic instability is detected with narrow-band peaks in the spectral response at a number of frequencies (500 kHz to 1.29 MHz). The data indicate that the instability driving the boundary layer to turbulence is acoustic in nature. Preliminary analysis indicates that there is not a significant difference between N2 and air acoustic boundary layer disturbance amplification factors for the representative cases presented. Computation of acoustic damping by thermo-chemical relaxation processes is presented for the same representative cases, and indicates that there is a negligible amount of absorption for both air and N_2 at the observed disturbance frequencies.", "date": "2013-01-07", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2013-0521", "id_number": "CaltechAUTHORS:20190826-092411647", "isbn": "9781624101816", "book_title": "51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190826-092411647", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)" } ] }, "other_numbering_system": { "items": [ { "id": "2013-0521", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2013-521", "primary_object": { "basename": "2013_AIAA_Differential_Interferometric_Measurement_of_Instability_at_Two_Points_in_a_Hypervelocity_Boundary_Layer.pdf", "url": "https://authors.library.caltech.edu/records/w8186-j9128/files/2013_AIAA_Differential_Interferometric_Measurement_of_Instability_at_Two_Points_in_a_Hypervelocity_Boundary_Layer.pdf" }, "pub_year": "2013", "author_list": "Parziale, N. J.; Shepherd, J. E.; et el." }, { "id": "https://authors.library.caltech.edu/records/6fnfq-63589", "eprint_id": 50077, "eprint_status": "archive", "datestamp": "2023-08-19 14:14:29", "lastmod": "2023-10-17 22:29:35", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Flaherty-W", "name": { "family": "Flaherty", "given": "W." } }, { "id": "Reedy-T-M", "name": { "family": "Reedy", "given": "Todd M." } }, { "id": "Elliott-G-S", "name": { "family": "Elliott", "given": "Gregory S." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "J. M." }, "orcid": "0000-0003-3129-5035" }, { "id": "Schmit-R-F", "name": { "family": "Schmit", "given": "Ryan F." } }, { "id": "Crafton-J", "name": { "family": "Crafton", "given": "J." } } ] }, "title": "Investigation of Cavity Flow Using Fast-Response Pressure Sensitive Paint", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2013 by William Flaherty. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.\n\nAIAA 2013-0678.\n\nThe authors would like to thank the Air Force Research Laboratories for supporting this research as\npart of a Phase II SBIR program with Ryan Schmit and Heidi Wilken as technical monitors. Any opinions,\nfindings, and conclusions or recommendations expressed in this material are those of the authors and do\nnot necessarily reflect the views of AFRL. Additionally, we would like to thank the facility personnel at the\nTGF. Approved for public release; distribution is unlimited; Case Number 88ABW-2012-6449.", "abstract": "An experimental study was conducted to investigate the pressure \nfluctuations on the\nentire side wall of a rectangular cavity with an L/D of 5.67 using fast-response pressure\nsensitive paint. Additionally, the performance of four different passive \nflow-control devices\nwas quantified. Experiments were conducted in the Trisonic Gasdynamics Facility at the\nAir Force Research Laboratory at Mach 0.7 and 1.5. The frequency spectrum (including\nRossiter tones) and sound pressure levels (SPLs) obtained from the pressure sensitive paint\n(PSP) measurements are validated against data taken with conventional dynamic pressure\nsensors. The complex \nflow phenomena over the cavity wall were visualized, and full wall\npressure spectra were calculated. The rod in cross \nflow showed the best peak suppression,\nfollowed closely by the \nflat spoiler. The large triangular step showed some peak suppression, while the ridges did not suppress the peaks at all. High resolution measurements of\npressure \nfluctuations on the wall allowed for the visualization of SPL distribution over the\nentire cavity wall. This revealed a strong dependence between the Rossiter tone modes\nand the spatial distribution of SPL that was not possible to resolve with discrete pressure\ntransducers.", "date": "2013-01", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Red Hook, NY", "id_number": "CaltechAUTHORS:20140926-151438811", "isbn": "9781627481946", "book_title": "51st AIAA aerospace sciences meeting including the new horizons forum and aerospace exposition 2013", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140926-151438811", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Research Laboratories" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2013-678", "pub_year": "2013", "author_list": "Flaherty, W.; Reedy, Todd M.; et el." }, { "id": "https://authors.library.caltech.edu/records/7fwn7-22w61", "eprint_id": 49999, "eprint_status": "archive", "datestamp": "2023-08-19 14:14:21", "lastmod": "2023-10-17 22:25:59", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Flaherty-W", "name": { "family": "Flaherty", "given": "W." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "J. M." }, "orcid": "0000-0003-3129-5035" } ] }, "title": "Hypervelocity Boundary Layer Studies for Inward Turning Inlets", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2013 by University of Illinois. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.\n\nThis work was funded through the Air Force Office of Scientific Research YIP award FA9550-08-1-0172\nwith Dr. John Schmisseur as program manager. The authors would like to thank Ryan Fontaine, Dr. Manu\nSharma, Andrew Knisely and Dr. Andy Swantek for their contributions to this work.", "abstract": "Inward turning hypersonic vehicle inlets have the theoretical potential to achieve higher\nefficiency than conventional two-dimensional geometries. However, the design of axisymmetric, streamtraced inlets depends on the capability to model boundary layer behavior\nover surfaces with concave curvature. In this work, we carry out a fundamental study of\nboundary layers flows, which are known to be significantly influenced by three-dimensional\neffects, at high stagnation-enthalpy, hypersonic conditions over surfaces with different concave geometry. Surface heat transfer and boundary layer visual thickness data over models\nwith cubic, quadratic and blended concave surface curvature are compared with a flat plate\nbaseline case. For all models, concave surface curvature produces an increase in the heat\nflux over flat plate laminar values. We demonstrate that reasonable estimates of the laminar heat flux augmentation due to concave surface curvature may be obtained from the\nlocal turning angle at the conditions of these experiments.", "date": "2013-01", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Red Hook, NY", "id_number": "CaltechAUTHORS:20140924-132729673", "isbn": "9781627481946", "book_title": "51st AIAA aerospace sciences meeting including the new horizons forum and aerospace exposition 2013", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140924-132729673", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR) YIP Award", "grant_number": "FA9550-08-1-0172" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "pub_year": "2013", "author_list": "Flaherty, W. and Austin, J. M." }, { "id": "https://authors.library.caltech.edu/records/bfbgg-tmr10", "eprint_id": 71865, "eprint_status": "archive", "datestamp": "2023-08-19 13:43:38", "lastmod": "2024-01-13 20:19:09", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Dani-Ashwin-P", "name": { "family": "Dani", "given": "Ashwin P." } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Hutchinson-Seth", "name": { "family": "Hutchinson", "given": "Seth" }, "orcid": "0000-0002-3949-6061" } ] }, "title": "Observer Design for Stochastic Nonlinear Systems using Contraction Analysis", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2012 IEEE. \n\nDate Added to IEEE Xplore: 04 February 2013. \n\nThis project was supported by the Office of Naval Research (ONR) under Award No. N00014-11-1-0088. \n\nThis paper benefited from discussions with Prof. Jean-Jacques Slotine. We thank the anonymous reviewers for their valuable comments.", "abstract": "This paper presents a new observer for It\u00f4 stochastic nonlinear systems with guaranteed stability. Contraction analysis is used to analyze incremental stability of the observer for an It\u00f4 stochastic nonlinear system. A bound on the mean squared distance between the trajectories of original dynamics and the observer dynamics is obtained as a function of contraction rate and maximum noise intensity. The observer design is based on non-unique state-dependent coefficient (SDC) forms which parametrize the nonlinearity in an extended linear form. In this paper, a convex combination of several parametrizations is used. An optimization problem with state-dependent linear matrix inequality (SDLMI) constraints is formulated to select the free parameters of the convex combination for achieving faster convergence and robustness against disturbances. Moreover, the L_2 norm of the disturbance and noise to the estimation error is shown to be finite. The present algorithm shows improved performance in comparison to the extended Kalman filter (EKF) and the state-dependent differential Riccati equation (SDDRE) filter in simulation.", "date": "2012-12", "date_type": "published", "publisher": "IEEE", "place_of_pub": "New York, NY", "pagerange": "6028-6035", "id_number": "CaltechAUTHORS:20161109-083117350", "isbn": "978-1-4673-2066-5", "book_title": "2012 IEEE 51st IEEE Conference on Decision and Control (CDC)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161109-083117350", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-11-1-0088" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/CDC.2012.6425977", "pub_year": "2012", "author_list": "Dani, Ashwin P.; Chung, Soon-Jo; et el." }, { "id": "https://authors.library.caltech.edu/records/9bghm-w1d64", "eprint_id": 71869, "eprint_status": "archive", "datestamp": "2023-08-19 13:43:45", "lastmod": "2024-01-13 20:19:11", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Paranjape-A-A", "name": { "family": "Paranjape", "given": "Aditya A." }, "orcid": "0000-0002-3164-3215" }, { "id": "Guan-Jinyu", "name": { "family": "Guan", "given": "Jinyu" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Krstic-Miroslav", "name": { "family": "Krstic", "given": "Miroslav" } } ] }, "title": "PDE Boundary Control for Euler-Bernoulli Beam Using a Two Stage Perturbation Observer", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2012 IEEE. \n\nDate Added to IEEE Xplore: 04 February 2013. \n\nThis project was supported by the U.S. Army Research Office (ARO) under Award No W911NF-10-1-0296.", "abstract": "A novel perturbation observer-based PDE boundary control law for beam bending is derived based on a combination of perturbation observers and polynomial trajectory planning. The perturbation observer consists of two components. The first stage employs the \"particular\" solution of the original dynamics with disturbances while its boundary conditions are set to zero. In contrast, the dynamics of the \"homogeneous component\" are independent of the beam dynamics, but its boundary conditions are identical to those of the beam. A tracking boundary control law, based on trajectory planning, is designed for the homogeneous component, and the same control signal is also applied to the beam. The stability of the adaptive perturbation-observer is proven by Lyapunov stability in the spatial L2 sense, while stability conditions are derived for a finite dimensional ODE analogue of the infinite dimensional closed loop PDE system. This paper also reports on one of the first experimental demonstrations of a controller designed entirely using a PDE boundary control formulation.", "date": "2012-12", "date_type": "published", "publisher": "IEEE", "place_of_pub": "New York, NY", "pagerange": "4442-4448", "id_number": "CaltechAUTHORS:20161109-084215066", "isbn": "978-1-4673-2066-5", "book_title": "51st IEEE Conference on Decision and Control (CDC)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161109-084215066", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Army Research Office (ARO)", "grant_number": "W911NF-10-1-0296" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/CDC.2012.6426058", "pub_year": "2012", "author_list": "Paranjape, Aditya A.; Guan, Jinyu; et el." }, { "id": "https://authors.library.caltech.edu/records/s3r1v-tpr82", "eprint_id": 71864, "eprint_status": "archive", "datestamp": "2023-08-19 13:03:25", "lastmod": "2023-10-23 17:17:01", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Rao-Dushyant", "name": { "family": "Rao", "given": "Dushyant" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Hutchinson-Seth", "name": { "family": "Hutchinson", "given": "Seth" }, "orcid": "0000-0002-3949-6061" } ] }, "title": "CurveSLAM: An approach for vision-based navigation without point features", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2012 IEEE. \n\nDate Added to IEEE Xplore: 24 December 2012. \n\nThis work was supported by the Office of Naval Research (ONR) under Award No. N00014-11-1-0088.", "abstract": "Existing approaches to visual Simultaneous Localization and Mapping (SLAM) typically utilize points as visual feature primitives to represent landmarks in the environment. Since these techniques mostly use image points from a standard feature point detector, they do not explicitly map objects or regions of interest. Our work is motivated by the need for different SLAM techniques in path and riverine settings, where feature points can be scarce or may not adequately represent the environment. Accordingly, the proposed approach uses cubic B\u00e9zier curves as stereo vision primitives and offers a novel SLAM formulation to update the curve parameters and vehicle pose. This method eliminates the need for point-based stereo matching, with an optimization procedure to directly extract the curve information in the world frame from noisy edge measurements. Further, the proposed algorithm enables navigation with fewer feature states than most point-based techniques, and is able to produce a map which only provides detail in key areas. Results in simulation and with vision data validate that the proposed method can be effective in estimating the 6DOF pose of the stereo camera, and can produce structured, uncluttered maps.", "date": "2012-10", "date_type": "published", "publisher": "IEEE", "place_of_pub": "New York, NY", "pagerange": "4198-4204", "id_number": "CaltechAUTHORS:20161109-082124457", "isbn": "978-1-4673-1736-8", "book_title": "2012 IEEE/RSJ International Conference on Intelligent Robots and Systems", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161109-082124457", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-11-1-0088" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/IROS.2012.6385764", "pub_year": "2012", "author_list": "Rao, Dushyant; Chung, Soon-Jo; et el." }, { "id": "https://authors.library.caltech.edu/records/jqfxj-8t304", "eprint_id": 103328, "eprint_status": "archive", "datestamp": "2023-08-19 12:56:34", "lastmod": "2024-01-15 04:30:26", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bompadre-A", "name": { "family": "Bompadre", "given": "Agust\u00edn" } }, { "id": "Perotti-L-E", "name": { "family": "Perotti", "given": "Luigi E." } }, { "id": "Cyron-C-J", "name": { "family": "Cyron", "given": "Christian J." } }, { "id": "Ortiz-M", "name": { "family": "Ortiz", "given": "Michael" }, "orcid": "0000-0001-5877-4824" } ] }, "title": "HOLMES: Convergent Meshfree Approximation Schemes of Arbitrary Order and Smoothness", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "High-order meshfree interpolation", "note": "\u00a9 2013 Springer-Verlag Berlin Heidelberg. \n\nFirst Online: 27 September 2012. \n\nThe support of the Department of Energy National Nuclear Security Administration under Award Number DE-FC52-08NA28613 through Caltech's ASC/PSAAP Center for the Predictive Modeling and Simulation of High Energy Density Dynamic Response of Materials is gratefully acknowledged. The third author (C.J.C.) gratefully acknowledges the support by the International Graduate School of Science and Engineering of the Technische Universit\u00e4t M\u00fcnchen.", "abstract": "Local Maximum-Entropy (LME) approximation schemes are meshfree approximation schemes that satisfy consistency conditions of order 1, i.e., they approximate affine functions exactly. In addition, LME approximation schemes converge in the Sobolev space W^(1,p), i.e., they are C\u2070-continuous in the conventional terminology of finite-element interpolation. Here we present a generalization of the Local Max-Ent approximation schemes that are consistent to arbitrary order, i.e., interpolate polynomials of arbitrary degree exactly, and which converge in W^(k,p), i.e., they are C^k -continuous to arbitrary order k. We refer to these approximation schemes as High Order Local Maximum-Entropy Approximation Schemes (HOLMES). We prove uniform error bounds for the HOLMES approximates and their derivatives up to order k. Moreover, we show that the HOLMES of order k is dense in the Sobolev Space W^(k,p), for any 1 \u2264 p < \u221e. The good performance of HOLMES relative to other meshfree schemes in selected test cases is also critically appraised.", "date": "2012-09-27", "date_type": "published", "publisher": "Springer", "place_of_pub": "Berlin", "pagerange": "111-126", "id_number": "CaltechAUTHORS:20200519-145536180", "isbn": "978-3-642-32978-4", "book_title": "Meshfree Methods for Partial Differential Equations VI", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200519-145536180", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Department of Energy (DOE)", "grant_number": "DE-FC52-08NA28613" }, { "agency": "Technische Universit\u00e4t M\u00fcnchen" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Griebel-M", "name": { "family": "Griebel", "given": "Michael" } }, { "id": "Schweitzer-M-A", "name": { "family": "Schweitzer", "given": "Marc Alexander" } } ] }, "doi": "10.1007/978-3-642-32979-1_7", "pub_year": "2012", "author_list": "Bompadre, Agust\u00edn; Perotti, Luigi E.; et el." }, { "id": "https://authors.library.caltech.edu/records/yh6k8-0cf80", "eprint_id": 103323, "eprint_status": "archive", "datestamp": "2023-08-19 12:45:59", "lastmod": "2024-01-15 04:30:22", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Rauls-M-B", "name": { "family": "Rauls", "given": "Michael" } }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "Guruswami" }, "orcid": "0000-0002-2912-0001" } ] }, "title": "Shock Waves in a Model Particulate Composite", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2013 The Society for Experimental Mechanics, Inc. \n\nFirst Online: 13 September 2012. \n\nThe support of the Air Force Office of Scientific Research through the University Center of Excellence: High-Rate Deformation Physics of Heterogeneous Materials at the California Institute of Technology is gratefully acknowledged.", "abstract": "Propagation of shock waves in heterogeneous media is examined. A model particulate composite is proposed, consisting of silica glass spheres (100\u2013200 \u03bcm diameter) embedded in a poly methyl methacrylate (PMMA) matrix. Various volume fractions and particle sizes will be examined to determine and optimum configuration for dissipation of energy as the shock passes through the sample thickness. Composite fabrication techniques are discussed and an experimental and modeling approach is proposed.", "date": "2012-09-13", "date_type": "published", "publisher": "Springer", "place_of_pub": "New York, NY", "pagerange": "295-296", "id_number": "CaltechAUTHORS:20200519-142109812", "isbn": "978-1-4614-4237-0", "book_title": "Dynamic Behavior of Materials", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200519-142109812", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1007/978-1-4614-4238-7_37", "pub_year": "2012", "author_list": "Rauls, Michael and Ravichandran, Guruswami" }, { "id": "https://authors.library.caltech.edu/records/eggg1-r7195", "eprint_id": 103321, "eprint_status": "archive", "datestamp": "2023-08-22 06:53:07", "lastmod": "2024-01-15 04:30:18", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Thevamaran-R", "name": { "family": "Thevamaran", "given": "Ramathasan" }, "orcid": "0000-0001-5058-6167" }, { "id": "Daraio-C", "name": { "family": "Daraio", "given": "Chiara" }, "orcid": "0000-0001-5296-4440" } ] }, "title": "Dynamics of Multilayered Structures of VACNTs with Metallic Inter-layers", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Carbon nanotubes; Wave propagation; Multilayered structures; Nonlinear dynamics; Localized deformation", "note": "\u00a9 2013 The Society for Experimental Mechanics, Inc. \n\nFirst Online: 13 September 2012. \n\nThis work is supported by the Institute for Collaborative Biotechnologies, under contract W911NF-09-D-0001 with the Army Research Office.", "abstract": "We study the dynamic behavior of periodic multilayered structures composed of compliant freestanding vertically aligned carbon nanotube (VACNT) arrays alternating with rigid metallic inter-layers, subjected to small transient excitations. The presence of intrinsically nonlinear effects in VACNTs arrays enable us to create materials and structures with tunable properties in which, for example, the stiffness can be tuned over a large range. As a result, the dynamic stress propagation properties in these materials can be tailored to specific applications.", "date": "2012-09-13", "date_type": "published", "publisher": "Springer", "place_of_pub": "New York, NY", "pagerange": "463-465", "id_number": "CaltechAUTHORS:20200519-135320125", "isbn": "978-1-4614-4237-0", "book_title": "Dynamic Behavior of Materials", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200519-135320125", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Army Research Office (ARO)", "grant_number": "W911NF-09-D-0001" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Chalivendra-V-B", "name": { "family": "Chalivendra", "given": "Vijaya" } }, { "id": "Song-Bo", "name": { "family": "Song", "given": "Bo" } }, { "id": "Casem-D", "name": { "family": "Casem", "given": "Daniel" } } ] }, "doi": "10.1007/978-1-4614-4238-7_59", "pub_year": "2012", "author_list": "Thevamaran, Ramathasan and Daraio, Chiara" }, { "id": "https://authors.library.caltech.edu/records/2vcvv-96963", "eprint_id": 98212, "eprint_status": "archive", "datestamp": "2023-08-19 12:41:23", "lastmod": "2023-10-18 17:09:24", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Rabinovitch-J", "name": { "family": "Rabinovitch", "given": "Jason" }, "orcid": "0000-0002-1914-7964" }, { "id": "Goel-Ashish", "name": { "family": "Goel", "given": "Ashish" } }, { "id": "Niedzielska-U", "name": { "family": "Niedzielska", "given": "Urszula" } }, { "id": "Ganesan-S", "name": { "family": "Ganesan", "given": "Sriram" } }, { "id": "Forman-R-E", "name": { "family": "Forman", "given": "Rachel E." } } ] }, "title": "Vault-1 - A Mission Architecture for Human Exploration of Near-Earth Objects", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2012 Jason Rabinovitch. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission. \n\nThis study was conducted as a part of the 2011 Caltech Space Challenge, a week long workshop/competition directed towards the U.S.A Presidents initiative of sending astronauts to an asteroid by 2025. This challenge worked to address the 2010 United States National Space Vision, as well as satisfying growing international interest in the exploration of Near Earth Objects. The challenge was hosted by the Keck Institute for Space Studies (KISS), and held at the California Institute of Technology from Sept 12-16, 2011. The event was organized by two graduate students studying at the California Institute of Technology, Prakhar Mehrortra and Jonathan Mihaly. The event was managed by Michele Judd, the Managing Director for the Keck Institute for Space Studies, and the student organizers were mentored by Dr. Donald Yeomans, John D. Baker, and Professor Paul E. Dimotakis. 32 international participants representing 12 nations were invited to participate in the challenge after two rounds of selection process. The participants were divided into two teams - Team Voyager and Team Explorer, and were challenged to prepare competing proposals for the first manned mission to a Near Earth Object. \n\nWe would like to acknowledge the contributions of our team members Emmet M. Cleary, Aditi J. Dighe, Ken P.L. Ho, Arlen Kam, Paola Libraro, Daniel Y. Lo, Pascal Renten, Apoorv Sharma, Michael A. Skeen, Tomohiro Yamaguchi and Samuel R. Zarovy, and our project mentors Dr. Paul E. Dimotakis, Dr. Donald K. Yeomans, Nigel Angold, Nathan Strange and Aline Zimmer. Special thanks also go to Michele Judd, for making this event possible. In addition we would like to thank the sponsors of this event, Lockheed Martin, SpaceX, Orbital Sciences Corporation, Analytical Graphics Inc., Mrs. Helen Keeley, Dr. Louis J. Alpinieri, and Dr. Fernando Fernandez\n\nPublished - voyager-aiaa-2012.pdf
", "abstract": "In 2011, the Keck Institute for Space Studies hosted the Caltech Space Challenge, a week long workshop/competition directed towards the President's initiative of sending astronauts to an asteroid by 2025. Two teams composed of 16 students each, representing 12 different nations, competed to prepare a mission proposal by the end of the week. This report highlights some of the work done by Team Voyager. Not only is this work useful in showing that a manned mission to a Near-Earth Object is feasible by 2025, but it also demonstrates the utility of intense, relatively short student competitions. This study is an outline of Vault-1, a proposed human mission to a Near-Earth Object. In addition to continuing human exploration, Vault-1 aims to make new discoveries about the origins of the Solar System, to develop technologies geared towards deep space exploration and a manned Mars mission, and to gain critical knowledge and experience to better protect Earth from future asteroid impacts. The primary target of this endeavor is 1999AO10, an asteroid that is larger than 30 m that also has an achievable mission duration of less than 200 days. 2000SG344 is a viable secondary target. Vault-1 will nominally carry 3 crew members to 1999AO10; after 14 days at the asteroid, the astronauts will return safely to the Earth with samples from the asteroid.", "date": "2012-09-11", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2012-5113", "id_number": "CaltechAUTHORS:20190826-092411944", "isbn": "9781600869402", "book_title": "AIAA SPACE 2012 Conference & Exposition", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190826-092411944", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Lockheed-Martin Corporation" }, { "agency": "SpaceX" }, { "agency": "Orbital Sciences Corporation" }, { "agency": "Analytical Graphics" }, { "agency": "Helen Keeley" }, { "agency": "Louis J. Alpinieri" }, { "agency": "Fernando Fernandez" } ] }, "other_numbering_system": { "items": [ { "id": "2012-5113", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Keck-Institute-for-Space-Studies" } ] }, "doi": "10.2514/6.2012-5113", "primary_object": { "basename": "voyager-aiaa-2012.pdf", "url": "https://authors.library.caltech.edu/records/2vcvv-96963/files/voyager-aiaa-2012.pdf" }, "pub_year": "2012", "author_list": "Rabinovitch, Jason; Goel, Ashish; et el." }, { "id": "https://authors.library.caltech.edu/records/p2qa8-wj281", "eprint_id": 103341, "eprint_status": "archive", "datestamp": "2023-08-22 06:50:41", "lastmod": "2024-01-15 04:30:32", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kovalchick-C", "name": { "family": "Kovalchick", "given": "Christopher" } }, { "id": "Xia-Shuman", "name": { "family": "Xia", "given": "Shuman" } }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "Guruswami" }, "orcid": "0000-0002-2912-0001" } ] }, "title": "Cohesive Zone Law Extraction from an Experimental Peel Test", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Cohesive zone; Peeling; Adhesion", "note": "\u00a9 2013 The Society for Experimental Mechanics, Inc. \n\nFirst Online: 06 September 2012.", "abstract": "The measurement of interface mechanical properties between an adhesive layer and a substrate is significant for optimization of a high-quality interface. A common method for measuring these properties is the peel test. Although analytical models exist for the peeling of elastic adhesives from smooth surfaces, there is a need for rigorous experiments in this area. Tests are conducted using a peel arrangement capable of peel angles from 0\u00b0 to 180\u00b0. Experimental validation is achieved through a series of displacement-controlled tests using elastic adhesive tapes. The steady-state peel force is measured at each angle and compared to the predicted values based upon the governing relations of Kendall and Rivlin.\n\nThe fibrillation zone of a simple adhesive material is imaged at the contact point between the adhesive and a rigid surface. By quantifying the size of this process zone, an inverse formulation is developed to extract an angle-dependent cohesive zone law based upon finite deformation beam theory. The adhesion energy during a peel test is then determined along with the force distribution in the process zone. This local method of determining the adhesion energy is compared to the global method of Rivlin in the context of finite deformations, showing good agreement.", "date": "2012-09-06", "date_type": "published", "publisher": "Springer", "place_of_pub": "New York, NY", "pagerange": "237-245", "id_number": "CaltechAUTHORS:20200520-073717282", "isbn": "978-1-4614-4225-7", "book_title": "Experimental and Applied Mechanics", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200520-073717282", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Ventura-C-E", "name": { "family": "Ventura", "given": "Carlos E." } }, { "id": "Crone-W-C", "name": { "family": "Crone", "given": "Wendy C." } }, { "id": "Furlong-C", "name": { "family": "Furlong", "given": "Cosme" } } ] }, "doi": "10.1007/978-1-4614-4226-4_28", "pub_year": "2012", "author_list": "Kovalchick, Christopher; Xia, Shuman; et el." }, { "id": "https://authors.library.caltech.edu/records/m8447-nyn62", "eprint_id": 37328, "eprint_status": "archive", "datestamp": "2023-08-19 12:33:22", "lastmod": "2023-10-23 17:22:28", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Siriki-Hemanth", "name": { "family": "Siriki", "given": "H." } }, { "id": "Rosakis-A-J", "name": { "family": "Rosakis", "given": "A. J." }, "orcid": "0000-0003-0559-0794" }, { "id": "Krishnan-Swaminathan", "name": { "family": "Krishnan", "given": "S." }, "orcid": "0000-0002-2594-1523" }, { "id": "Bhat-Harsha-S", "name": { "family": "Bhat", "given": "H. S." } }, { "id": "Lu-Xiao", "name": { "family": "Lu", "given": "X." } } ] }, "title": "A Recursive Division Stochastic Strike-Slip Seismic\n Source Algorithm Using Insights from Laboratory\n Earthquakes", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "seismic risk quantification, source model generation algorithm, laboratory earthquakes", "note": "This work is funded in part by NSF: CMMI Award No. 0926962. We thank Thomas Heaton (Caltech), Jean Paul\nAmpuero (Caltech), Dimitri Komatitsch (University of Pau, France), Martin Mai (KAUST), Rob Graves\n(USGS), and Chen Ji (UCSB) for offering valuable insights into various aspects of source physics and seismic\nwave propagation.", "abstract": "There are a sparse number of credible source models available from past earthquakes and a stochastic source\nmodel generation algorithm thus becomes necessary for robust risk quantification using scenario earthquakes.\nWe present an algorithm that combines the physics of fault rupture as imaged in laboratory earthquakes with\nstress estimates on the fault constrained by field observations to generate probability distributions of rise-time\nand rupture-speed for strike-slip earthquakes. The algorithm is validated through a statistical comparison of peak\nground velocity at 636 sites in Southern California from synthetic ground motion histories simulated for 10\nrupture scenarios using a stochastically generated source model against that generated using a kinematic source\nmodel from a finite source inversion. This model, selected from a set of 5 stochastically generated source\nmodels, produces ground shaking intensities in Southern California with a median that is closest to the median\nintensity of shaking from all 5 source models (and 10 rupture scenarios per model).", "date": "2012-09", "date_type": "published", "publisher": "International Association for Earthquake Engineering", "id_number": "CaltechAUTHORS:20130305-152759959", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130305-152759959", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF CMMI Award", "grant_number": "0926962" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "pub_year": "2012", "author_list": "Siriki, H.; Rosakis, A. J.; et el." }, { "id": "https://authors.library.caltech.edu/records/9xn1a-9fq55", "eprint_id": 98714, "eprint_status": "archive", "datestamp": "2023-09-15 06:22:49", "lastmod": "2023-10-23 21:25:58", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Seele-R", "name": { "family": "Seele", "given": "Roman" } }, { "id": "Chen-Chunmei", "name": { "family": "Chen", "given": "Chunmei" } }, { "id": "Bhamburkar-C", "name": { "family": "Bhamburkar", "given": "Cristina" } }, { "id": "Wygnanski-I-J", "name": { "family": "Wygnanski", "given": "Israel" } } ] }, "title": "Some Effects of Blowing, Suction and Trailing Edge Bluntness on Flow Separation from Thick Airfoils; Computations & Measurements", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2012 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 10 Aug 2012.", "abstract": "The relative effectiveness or blowing and suction in controlling separation and circulation is assessed in the present paper. This paper focuses on low momentum input from the leading and trailing edge regions and the effects of a sharp and round trolling edges. Blowing is most effective when it is applied near but upstream of the separation location for the narrowest slot possible. The effectiveness of suction improves when the slot is located near but downstream or the natural separation location and it is as wide as possible. The effects of adding trailing edge shapes on separation control were also explored. Most of the data presented was taken at incompressible speeds and at Re < 2.5*10^5.", "date": "2012-08-10", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2011-3357", "id_number": "CaltechAUTHORS:20190918-094717707", "isbn": "978-1-62410-145-8", "book_title": "29th AIAA Applied Aerodynamics Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190918-094717707", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2011-3357", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2011-3357", "pub_year": "2012", "author_list": "Seele, Roman; Chen, Chunmei; et el." }, { "id": "https://authors.library.caltech.edu/records/s9met-t5977", "eprint_id": 73150, "eprint_status": "archive", "datestamp": "2023-08-19 11:59:53", "lastmod": "2023-10-24 15:04:43", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Morgan-Daniel", "name": { "family": "Morgan", "given": "Daniel" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Hadaegh-F-Y", "name": { "family": "Hadaegh", "given": "Fred" } } ] }, "title": "Spacecraft Swarm Guidance Using a Sequence of Decentralized Convex Optimizations", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2012 American Institute of Aeronautics and Astronautics. \n\nThis research was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. \u00a9 2012 California Institute of Technology. \n\nThis work was supported by a NASA Office of the Chief Technologists Space Technology Research Fellowship. Government sponsorship acknowledged. Additional thanks to Saptarshi Bandyopadhyay (University of Illinois), Behcet Acikmese and Dan Scharf (Jet Propulsion Laboratory) for constructive comments.\n\nPublished - Morgan_SpacecraftSwarmGuidance.pdf
", "abstract": "This paper presents partially decentralized path planning algorithms for swarms of spacecraft composed of hundreds to thousands of agents with each spacecraft having limited computational capabilities. In our prior work, J2-invariant orbits have been found to provide collision free motion for hundreds of orbits. This paper develops algorithms for the\nswarm reconfiguration which involves transferring from one J2-invariant orbit to another avoiding collisions and minimizing fuel. To perform collision avoidance, it is assumed that the spacecraft can communicate their trajectories with each other. The algorithm uses\nsequential convex programming to solve a series of approximate path planning problems until the solution converges. Two decentralized methods are developed: a serial method where the spacecraft take turn updating their trajectories and a parallel method where all of the spacecraft update their trajectories simultaneously.", "date": "2012-08", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2012-4583", "id_number": "CaltechAUTHORS:20161222-111933253", "isbn": "978-1-62410-182-3", "book_title": "AIAA/AAS Astrodynamics Specialist Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161222-111933253", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" }, { "agency": "NASA Space Technology Research Fellowship" } ] }, "other_numbering_system": { "items": [ { "id": "2012-4583", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2012-4583", "primary_object": { "basename": "Morgan_SpacecraftSwarmGuidance.pdf", "url": "https://authors.library.caltech.edu/records/s9met-t5977/files/Morgan_SpacecraftSwarmGuidance.pdf" }, "pub_year": "2012", "author_list": "Morgan, Daniel; Chung, Soon-Jo; et el." }, { "id": "https://authors.library.caltech.edu/records/2naye-vf695", "eprint_id": 72405, "eprint_status": "archive", "datestamp": "2023-08-19 11:59:48", "lastmod": "2023-10-23 22:31:13", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Paranjape-A-A", "name": { "family": "Paranjape", "given": "Aditya" }, "orcid": "0000-0002-3164-3215" }, { "id": "Kim-Joseph", "name": { "family": "Kim", "given": "Joseph" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Closed-Loop Perching and Spatial Guidance Laws for Bio-Inspired Articulated Wing MAV", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2012 by Aditya A. Paranjape and Soon-Jo Chung. Published by the American Institute of Aeronautics and Astronautics (AIAA). \n\nThis project was supported by the Air Force Office of Scientific Research (AFOSR) under the Young Investigator Award Program (Grant No. FA95500910089) monitored by Dr. W. Larkin. The concept of wing articulation was presented to the authors by Dr. Gregg Abate at AFRL. Nihar Gandhi and Xichen Shi, both of them undergrad students, and Sana Ashraf, a graduate student at UIUC, helped build the aircraft and also participated in the experiments. Their contributions are gratefully acknowledged.\n\nPublished - AIAA_GNC_Perching_2012.pdf
", "abstract": "This paper presents the underlying theoretical developments and successful experimental demonstrations of perching of an aerial robot. The open-loop lateral-directional dynamics of the robot are inherently unstable because it lacks a vertical tail for agility, similar to birds. A unique feature of this robot is that it uses wing articulation for controlling the flight path angle as well as the heading. New guidance algorithms with guaranteed stability are obtained by rewriting the flight dynamic equations in the spatial domain rather than as functions of time, after which dynamic inversion is employed. It is shown that nonlinear dynamic inversion naturally leads to proportional-integral-derivative (PID) controllers, thereby providing an exact method for tuning the gains. The effectiveness of the proposed bio-inspired robot design and its novel closed-loop perching controller has been successfully demonstrated with perched landings on a human hand.", "date": "2012-08", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "pagerange": "Art. No.-2012", "id_number": "CaltechAUTHORS:20161129-114235228", "isbn": "978-1-60086-938-9", "book_title": "AIAA Guidance, Navigation, and Control Conference, 2012", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161129-114235228", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA95500910089" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2012-4979", "primary_object": { "basename": "AIAA_GNC_Perching_2012.pdf", "url": "https://authors.library.caltech.edu/records/2naye-vf695/files/AIAA_GNC_Perching_2012.pdf" }, "pub_year": "2012", "author_list": "Paranjape, Aditya; Kim, Joseph; et el." }, { "id": "https://authors.library.caltech.edu/records/c3x2c-0v428", "eprint_id": 98213, "eprint_status": "archive", "datestamp": "2023-08-19 11:49:06", "lastmod": "2023-10-18 17:09:27", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Tian-Vicky", "name": { "family": "Tian", "given": "Vicky" } }, { "id": "McKeon-B-J", "name": { "family": "McKeon", "given": "Beverley" }, "orcid": "0000-0003-4220-1583" }, { "id": "Leyva-I-A", "name": { "family": "Leyva", "given": "Ivett A." } } ] }, "title": "Split Stream Flow Past a Blunt Trailing Edge with Application to Combustion Instabilities", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2012 American Institute of Aeronautics and Astronautics. \n\nThe assistance of the Mechanical Engineering Shop at Caltech and undergraduate and graduate students of Caltech is gratefully acknowledged. The work was supported by the Air Force Research Laboratory, Lester Lees Aeronautics SURF Fellowship, Student Faculty Programs at Caltech, and Graduate Aerospace Laboratories at Caltech.\n\nAccepted Version - TianAIAA2012.pdf
", "abstract": "In shear coaxial injectors, commonly used for cryogenic liquid rocket engines, propellants traveling at different velocities are separated by the inner jet post before they come into contact with each other, mix, and combust. Knowing how the fluids mix and how susceptible they are to hydrodynamic instabilities is paramount for a successful liquid rocket engine. In this study, the wake behind a blunt trailing edge of a long plate, similar to an unwrapped coaxial injector, was studied in a water tunnel. Two fluid streams of different velocities were introduced on opposite sides of the plate. PIV was used to visualize and determine the influence of the velocity ratio of the split stream on the wake behavior. Measurements of the vortex shedding frequency were taken at various velocity ratios and compared with well characterized cases with a uniform free stream. Operating conditions ranged from Reynolds number 6,000 to 22,000 and velocity ratios 0.30 to 1.00.", "date": "2012-07-30", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2012-3807", "id_number": "CaltechAUTHORS:20190826-092412052", "isbn": "9781600869358", "book_title": "48th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190826-092412052", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Research Laboratory (AFRL)" }, { "agency": "Caltech Summer Undergraduate Research Fellowship (SURF)" }, { "agency": "Graduate Aerospace Laboratories (GALCIT)" } ] }, "other_numbering_system": { "items": [ { "id": "ADA572242", "name": "DTIC" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2012-3807", "primary_object": { "basename": "TianAIAA2012.pdf", "url": "https://authors.library.caltech.edu/records/c3x2c-0v428/files/TianAIAA2012.pdf" }, "pub_year": "2012", "author_list": "Tian, Vicky; McKeon, Beverley; et el." }, { "id": "https://authors.library.caltech.edu/records/bpm06-36575", "eprint_id": 41900, "eprint_status": "archive", "datestamp": "2023-08-19 11:36:26", "lastmod": "2023-10-25 14:53:37", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bitter-N-P", "name": { "family": "Bitter", "given": "Neal P." } }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "Joseph E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "Detonation and transition to detonation in partially water-filled pipes", "ispublished": "unpub", "full_text_status": "public", "keywords": "Explosions, Pipes, Water", "note": "\u00a9 2012 ASME.\n\nPublished - Bitter_2012p183.pdf
", "abstract": "Detonations and deflagration-to-detonation transition (DDT) are experimentally studied in horizontal pipes which are partially filled with water. The gas layer above the water is stoichiometric hydrogen-oxygen at 1 bar. For detonation cases, ignition and transition occur outside of the water-filled section. For DDT cases, ignition and transition occur over the surface of the water. Pressure and hoop strain are measured incrementally along the pipe, with pressure transducers located both above and below the water. The detonation wave produces an oblique shock train in the water, and the curvature of the pipe is seen to focus the shocks at the bottom, resulting in peak pressures that are 4\u20136 times higher than the peak detonation pressure. Such pressure amplification is observed for water depths of 0.25, 0.5, 0.75, 0.87, and 0.92 pipe diameters. For a water depth of 0.5 diameters, pressure is also recorded at several circumferential locations in order to measure the shock focusing phenomenon. Peak hoop strains are found to decrease with increasing water depth, and transition to detonation is seen to occur for water depths as high as 0.92 pipe diameters.", "date": "2012-07", "date_type": "published", "publisher": "ASME", "place_of_pub": "New York", "pagerange": "183-195", "id_number": "CaltechAUTHORS:20131011-132949425", "isbn": "978-0-7918-5504-1", "book_title": "Proceedings of the ASME 2012 Pressure Vessels & Piping Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131011-132949425", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1115/PVP2012-78539", "primary_object": { "basename": "Bitter_2012p183.pdf", "url": "https://authors.library.caltech.edu/records/bpm06-36575/files/Bitter_2012p183.pdf" }, "pub_year": "2012", "author_list": "Bitter, Neal P. and Shepherd, Joseph E." }, { "id": "https://authors.library.caltech.edu/records/p4b7s-w4z03", "eprint_id": 98214, "eprint_status": "archive", "datestamp": "2023-08-19 11:27:48", "lastmod": "2023-10-18 17:09:29", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Wallace-Ryan-D", "name": { "family": "Wallace", "given": "R. D." } }, { "id": "McKeon-B-J", "name": { "family": "McKeon", "given": "B. J." }, "orcid": "0000-0003-4220-1583" } ] }, "title": "Laminar Separation Bubble Manipulation with Dynamic Roughness", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2012 American Institute of Aeronautics and Astronautics.", "abstract": "The laminar separation over a symmetric, idealized airfoil was altered by employing a leading edge roughness element ahead of the separation point. Experimental tests were performed with a dynamic roughness, with a time-dependent amplitude, in order to determine the range of control authority associated with this type of leading edge manipulation. The dynamic roughness tests demonstrated the sensitivity of the separation to frequency perturbations at the leading edge induced by the roughness element. Two low dimensional analysis techniques, Proper Orthogonal Decomposition and Dynamic Mode Decomposition, were employed to examine the coupling between the wall motion and the flow, with a view to investigating the practicality of using leading edge roughness perturbations to in future closed loop control configurations.", "date": "2012-06-25", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2012-2680", "id_number": "CaltechAUTHORS:20190826-092412147", "isbn": "9781624101885", "book_title": "6th AIAA Flow Control Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190826-092412147", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2012-2680", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2012-2680", "pub_year": "2012", "author_list": "Wallace, R. D. and McKeon, B. J." }, { "id": "https://authors.library.caltech.edu/records/8chm5-faw77", "eprint_id": 98215, "eprint_status": "archive", "datestamp": "2023-08-19 11:27:53", "lastmod": "2023-10-18 17:09:32", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Damazo-J-S", "name": { "family": "Damazo", "given": "J." }, "orcid": "0000-0002-4155-7177" }, { "id": "Odell-J", "name": { "family": "Odell", "given": "J." } }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "J. E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "Boundary Layer Profile Behind Gaseous Detonation as it Affects Reflected Shock Wave Bifurcation", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2012 American Institute of Aeronautics and Astronautics. \n\nThis research is sponsored by the DHS through the University of Rhode Island, Center of Excellence for Explosives Detection. The authors would also like to thank Bahram Valiferdowsi for his help in designing the splitter plate as well as the Caltech SURF program for sponsoring Jeff Odell.\n\nPublished - DamazoAIAA2012.pdf
", "abstract": "The present study explores the flow field created by reflecting detonations using heat transfer and pressure measurements near the location of detonation reflection. Schlieren imaging techniques are used to examine the possibility of shock wave-boundary layer interaction. These measurements are compared to laminar boundary layer theory and a one- dimensional model of detonation reflection. Experiments were carried out in a 7.6 m long detonation tube with a rectangular test section using mixtures of stoichiometric hydrogen- oxygen with argon dilution of 0, 50, 67, and 83% at an initial pressure of 10, 25, and 40 kPa. Optical observations show that minimal interaction of the reflected shock wave results when propagating into the boundary layer created by the incident wave. The heat transfer rate is qualitatively consistent with the time dependent laminar boundary layer predictions, however the magnitude is consistently larger and substantial (factor of three) peak-to-peak fluctuations are observed. The pressure measurements show good agreement between predicted ideal incident and reflected wave speeds. The pressure amplitudes are under-predicted for no argon dilution cases particularly at 40 kPa, but in reasonable agreement for lower pressures and higher dilutions.", "date": "2012-06-25", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2012-2975", "id_number": "CaltechAUTHORS:20190826-092412235", "isbn": "9781600869334", "book_title": "42nd AIAA Fluid Dynamics Conference and Exhibit", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190826-092412235", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Department of Homeland Security" }, { "agency": "Caltech Summer Undergraduate Research Fellowship (SURF)" } ] }, "other_numbering_system": { "items": [ { "id": "2012-2975", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2012-2975", "primary_object": { "basename": "DamazoAIAA2012.pdf", "url": "https://authors.library.caltech.edu/records/8chm5-faw77/files/DamazoAIAA2012.pdf" }, "pub_year": "2012", "author_list": "Damazo, J.; Odell, J.; et el." }, { "id": "https://authors.library.caltech.edu/records/f4aay-d1k20", "eprint_id": 98217, "eprint_status": "archive", "datestamp": "2023-08-19 11:28:03", "lastmod": "2023-10-18 17:09:38", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Seele-R", "name": { "family": "Seele", "given": "Roman" } }, { "id": "Graff-E-C", "name": { "family": "Graff", "given": "Emilio" } }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "Morteza" }, "orcid": "0000-0003-0754-4193" }, { "id": "Taubert-L", "name": { "family": "Taubert", "given": "Lutz" } }, { "id": "Lin-John-C", "name": { "family": "Lin", "given": "John" }, "orcid": "0000-0003-2794-184X" }, { "id": "Wygnanski-I", "name": { "family": "Wygnanski", "given": "Israel" } } ] }, "title": "Improving Rudder Effectiveness with Sweeping Jet Actuators", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2012 American Institute of Aeronautics and Astronautics. \n\nThis research was supported by the National Aeronautics and Space Administration (NASA) under the Environmentally Responsible Aircraft (ERA) Project. The research was funded through NASA Technology, Engineering, and Aerospace Mission Support (TEAMS) Contract Task Order 097D3-NNL10AM26T.\n\nPublished - SeeleAIAA2012.pdf
", "abstract": "The application of active flow control on a vertical tail of a typical twin engine aircraft was investigated. Sweeping jets installed into the rudder surface were used and their effect was assessed by force measurements, flow visualization and local pressure distributions. The airfoil forming the tail is a NACA 0012 with a rudder using 35% of its chord. The tests were carried out at the Lucas Wind Tunnel at the California Institute of Technology at representative Reynolds numbers of up to Re=1.5 million. Multiple flap deflections and spanwise actuator configurations were tested resulting in an increase of up to 50-70% in side force depending on the free stream velocity and momentum input.", "date": "2012-06-25", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2012-3244", "id_number": "CaltechAUTHORS:20190826-092412418", "isbn": "9781624101885", "book_title": "6th AIAA Flow Control Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190826-092412418", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA", "grant_number": "097D3-NNL10AM26T" } ] }, "other_numbering_system": { "items": [ { "id": "2012-3244", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2012-3244", "primary_object": { "basename": "SeeleAIAA2012.pdf", "url": "https://authors.library.caltech.edu/records/f4aay-d1k20/files/SeeleAIAA2012.pdf" }, "pub_year": "2012", "author_list": "Seele, Roman; Graff, Emilio; et el." }, { "id": "https://authors.library.caltech.edu/records/jm9ad-f6b32", "eprint_id": 98219, "eprint_status": "archive", "datestamp": "2023-08-19 11:28:14", "lastmod": "2023-10-18 17:09:44", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Parziale-N-J", "name": { "family": "Parziale", "given": "N. J." }, "orcid": "0000-0001-9880-1727" }, { "id": "Rabinovitch-J", "name": { "family": "Rabinovitch", "given": "J." }, "orcid": "0000-0002-1914-7964" }, { "id": "Blanquart-G", "name": { "family": "Blanquart", "given": "G." }, "orcid": "0000-0002-5074-9728" }, { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "H. G." }, "orcid": "0000-0002-4903-8419" }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "J. E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "A Proposed Vertical Expansion Tunnel", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2012 American Institute of Aeronautics and Astronautics. \n\nThis work was sponsored in part by AFOSR/National Center for Hypersonic Research in Laminar Turbulent Transition, for which Dr. John Schmisseur and Dr. Deepak Bose are the program managers. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the Air Force Office of Scientific Research or the U.S. Government. \n\nThe authors would also like to thank Siddhartha Verma for his contribution to the work.\n\nAccepted Version - 2012_AIAA_A_Proposed_Vertical_Expansion_Tunnel.pdf
", "abstract": "Issues resulting from the rupture of the secondary diaphragm in an expansion tunnel may be mitigated by matching the test gas pressure and the accelerator gas pressure, orienting the tunnel vertically, and initially separating the test gas from the accelerator gas by density stratification. Two benefits are: 1) the removal of the diaphragm particulates in the test gas after its rupture and 2) the elimination of the wave system that is a result of a real secondary diaphragm having a finite thickness and mass. An inviscid perfect-gas analysis is performed to find the reservoir conditions available in the vertical expansion tunnel (VET) for comparison to a conventional expansion tunnel (ET) and a reflected shock tunnel (RST). A numerical inviscid perfect-gas analysis is presented to estimate the available test time in the VET. The effective reservoir conditions of the VET lie somewhere between the RST and the ET.", "date": "2012-06-25", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2012-3263", "id_number": "CaltechAUTHORS:20190826-092412604", "isbn": "9781600869334", "book_title": "42nd AIAA Fluid Dynamics Conference and Exhibit", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190826-092412604", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)" } ] }, "other_numbering_system": { "items": [ { "id": "2012-3263", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2012-3263", "primary_object": { "basename": "2012_AIAA_A_Proposed_Vertical_Expansion_Tunnel.pdf", "url": "https://authors.library.caltech.edu/records/jm9ad-f6b32/files/2012_AIAA_A_Proposed_Vertical_Expansion_Tunnel.pdf" }, "pub_year": "2012", "author_list": "Parziale, N. J.; Rabinovitch, J.; et el." }, { "id": "https://authors.library.caltech.edu/records/enaks-efj55", "eprint_id": 98216, "eprint_status": "archive", "datestamp": "2023-08-19 11:27:58", "lastmod": "2023-10-18 17:09:35", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Jewell-J-S", "name": { "family": "Jewell", "given": "Joseph S." }, "orcid": "0000-0002-4047-9998" }, { "id": "Parziale-N-J", "name": { "family": "Parziale", "given": "Nicholaus J." }, "orcid": "0000-0001-9880-1727" }, { "id": "Leyva-I-A", "name": { "family": "Leyva", "given": "Ivett A." } }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "Joseph E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "Turbulent Spot Observations within a Hypervelocity Boundary Layer on a 5-degree Half-Angle Cone", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2012 American Institute of Aeronautics and Astronautics. \n\nThe authors thank Mr. Bahram Valiferdowsi for his work with design, fabrication, and maintenance, and Prof. Hans Hornung for his advice and support. This project was sponsored by the Air Force Office of Scientific Research under award number FA9550-10-1-0491 and the NASA/AFOSR National Center for Hypersonic Research. The views expressed herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of AFOSR or the U.S. Government.\n\nAccepted Version - jjewell_Turbulent_Spot_Propagation.pdf
", "abstract": "Laminar to turbulent transition is a critically important process in hypersonic vehicle design. Higher thermal loads, by half an order of magnitude or more, result from the increased heat transfer due to turbulent flow. Drag, skin friction, and other flow properties are also significantly impacted. Transition to turbulence in initially laminar\nboundary layers can occur along many paths. In low-speed flow under ideal conditions (quiet freestream, nominally smooth surfaces with favorable or zero pressure gradient and minimal crossflow) transition occurs over a finite distance and is associated with the creation and growth of propagating patches of turbulent flow, known as turbulent spots. Spots may be due to the breakdown of linear instabilities or induced by \"bypass mechanisms\" associated with nonideal effects in the flow or model. H.W. Emmons (1951) was the first to propose that laminar boundary layers break down through the convergence of spots, after observations of a water-table analogy to air flow. Spot formation has been studied extensively in subsonic flows, a recent review of past and current work on spots in incompressible flows is given by Strand and Goldstein (2011).", "date": "2012-06-25", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2012-3062", "id_number": "CaltechAUTHORS:20190826-092412321", "isbn": "9781600869334", "book_title": "42nd AIAA Fluid Dynamics Conference and Exhibit", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190826-092412321", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-10-1-0491" }, { "agency": "NASA/JPL/Caltech" } ] }, "other_numbering_system": { "items": [ { "id": "2012-3062", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2012-3062", "primary_object": { "basename": "jjewell_Turbulent_Spot_Propagation.pdf", "url": "https://authors.library.caltech.edu/records/enaks-efj55/files/jjewell_Turbulent_Spot_Propagation.pdf" }, "pub_year": "2012", "author_list": "Jewell, Joseph S.; Parziale, Nicholaus J.; et el." }, { "id": "https://authors.library.caltech.edu/records/183as-j3b06", "eprint_id": 98218, "eprint_status": "archive", "datestamp": "2023-08-19 11:28:08", "lastmod": "2023-10-18 17:09:41", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Parziale-N-J", "name": { "family": "Parziale", "given": "N. J." }, "orcid": "0000-0001-9880-1727" }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "J. E." }, "orcid": "0000-0003-3181-9310" }, { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "H. G." }, "orcid": "0000-0002-4903-8419" } ] }, "title": "Reflected Shock Tunnel Noise Measurement by Focused Differential Interferometry", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2012 American Institute of Aeronautics and Astronautics. \n\nThanks to Bahram Valiferdowsi for the isometric views of the solid model of the facility. Also, thanks to Joe Jewell for helping to compute the run conditions. This work was sponsored by AFOSR/National Center for Hypersonic Research in Laminar-Turbulent Transition, for which Dr. John Schmisseur and Dr. Deepak Bose are the program managers. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the Air Force Office of Scientific Research or the U.S. Government.\n\nAccepted Version - ParzialeAIAA2012.pdf
", "abstract": "A series of experiments is conducted where a quantitative non-intrusive optical technique is used to investigate disturbances in the free-stream of T5, the free-piston driven reflected shock tunnel at Caltech. The optical technique, focused laser differential interferometry (FLDI), measures fluctuations in density. In the test matrix, reservoir enthalpy is varied while the reservoir pressure is held fixed. The results show the perturbations in density are not a strong function of the reservoir enthalpy. During one experiment, exceptional levels of noise were detected; this unique result is attributed to non-ideal operation of the shock tunnel. The data indicate that rms density fluctuations of less than 0.75% are achievable with attention to tunnel cleanliness. In addition, the spectral content of density fluctuation does not change throughout the test time.", "date": "2012-06-25", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2012-3261", "id_number": "CaltechAUTHORS:20190826-092412513", "isbn": "9781600869334", "book_title": "42nd AIAA Fluid Dynamics Conference and Exhibit", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190826-092412513", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)" } ] }, "other_numbering_system": { "items": [ { "id": "2012-3261", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2012-3261", "primary_object": { "basename": "ParzialeAIAA2012.pdf", "url": "https://authors.library.caltech.edu/records/183as-j3b06/files/ParzialeAIAA2012.pdf" }, "pub_year": "2012", "author_list": "Parziale, N. J.; Shepherd, J. E.; et el." }, { "id": "https://authors.library.caltech.edu/records/d2mcv-gjj33", "eprint_id": 100417, "eprint_status": "archive", "datestamp": "2023-08-19 11:23:25", "lastmod": "2023-10-18 19:56:08", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Marineau-E-C", "name": { "family": "Marineau", "given": "Eric" } }, { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "Hans" }, "orcid": "0000-0002-4903-8419" } ] }, "title": "Heat Flux Calibration of T5 Hypervelocity Shock Tunnel Conical Nozzle in Air", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2009 by the American Institute of Aeronautics and Astronautics, Inc.", "abstract": "The uniformity of the convective heating due to a free stream of hypervelocity air expanded through a conical nozzle is evaluated in the T5 free-piston reflected shock tunnel at Caltech. The stagnation-point heat flux is measured on a rake of ten one-inch-diameter spheres located at the nozzle exit plane. A total of eight shots (two shots at each of the four conditions) were performed with stagnation enthalpies varying from 9.5 to 21 MJ/kg and stagnation pressures from 20 to 60 MPa. Good uniformity was found as the standard deviation among gages ranged between \u00b14% and \u00b17% when the two gages located near the nozzle wall were excluded. Good heat flux shot-to-shot repeatability was also found as the standard deviation in stagnation-point beat flux between shots at a given condition was generally below \u00b14%. The nozzle expansion and flow over a single sphere were simulated using DPLR CFD code with a fully catalytic wall. Very good agreement was found between DPLR and the experiment as the differences between computation and experiment are under 8% for each condition which is significantly below the experimental uncertainties.", "date": "2012-06-15", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2009-1158", "id_number": "CaltechAUTHORS:20191223-140317843", "isbn": "978-1-60086-973-0", "book_title": "47th AIAA Aerospace Sciences Meeting including The New Horizons Forum and Aerospace Exposition", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191223-140317843", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2009-1158", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2009-1158", "pub_year": "2012", "author_list": "Marineau, Eric and Hornung, Hans" }, { "id": "https://authors.library.caltech.edu/records/71prh-fwv14", "eprint_id": 100402, "eprint_status": "archive", "datestamp": "2023-08-19 11:23:21", "lastmod": "2023-10-18 19:55:46", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Maddalena-L", "name": { "family": "Maddalena", "given": "Luca" } }, { "id": "Hosder-S", "name": { "family": "Hosder", "given": "S." } }, { "id": "Bonanos-A-M", "name": { "family": "Bonanos", "given": "A. M." } }, { "id": "Dimotakis-P-E", "name": { "family": "Dimotakis", "given": "P. E." } } ] }, "title": "Extended Conical Flow Theory for Design of Pressure Probes in Supersonic Flows with Moderate Flow Angularity and Swirl", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2009 by the American Institute of Aeronautics and Astronautics, Inc.", "abstract": "Total and static pressures are vital measurements in any supersonic experiment. By\nmeasuring these two pressures, the Mach number can be inferred. Most flows of interests\nare highly three dimensional, but with moderate swirl. Because of this three-dimensionality, the total and static pressures must be measured ideally at the same location.\nA miniature probe of 10deg. half-angle was designed and experimentally calibrated to asses\nthe effectiveness of the Krasnov similarity laws to scale the influence of the truncated tip\non the downstream cone surface pressure distribution. A recently developed uncertainty\nquantification approach based on polynomial chaos has been used to quantify the effect\nof geometric uncertainty coming from probe manufacturing tolerances on the measured\nMach number utilizing computational fluid dynamics. The relative variation in the Mach\nnumber due to geometric uncertainty was found to be less than 1.0%. The cone angle 'was\ndetermined to be the most dominant uncertain geometric parameter on the results as a\nresult of a sensitivity analysis. The applicability of the Krasnov similarity laws is proposed\nas a mean to circumvent or guide the traditional and expensive experimental approach\nused for the calibration of a multi-hole conical probe at zero angle of attack.", "date": "2012-06-15", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2009-1072", "id_number": "CaltechAUTHORS:20191223-103335301", "isbn": "978-1-60086-973-0", "book_title": "47th AIAA Aerospace Sciences Meeting including The New Horizons Forum and Aerospace Exposition", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191223-103335301", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2009-1072", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2009-1072", "pub_year": "2012", "author_list": "Maddalena, Luca; Hosder, S.; et el." }, { "id": "https://authors.library.caltech.edu/records/bytnn-jdg11", "eprint_id": 100510, "eprint_status": "archive", "datestamp": "2023-08-19 11:23:29", "lastmod": "2023-10-18 20:58:04", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hosder-S", "name": { "family": "Hosder", "given": "Serhat" } }, { "id": "Maddalena-L", "name": { "family": "Maddalena", "given": "Luca" } } ] }, "title": "Non-Intrusive Polynomial Chaos for the Stochastic CFD Study of a Supersonic Pressure Probe", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2009 by Hosder and Maddalena. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission. \n\nPublished Online: 15 Jun 2012.", "abstract": "The Point-Collocation Non-Intrusive Polynomial Chaos (NIPC) method utilizing Euler CFD simulations has been applied to the stochastic analysis of a pressure probe designed for Mach number measurements in three-dimensional supersonic flows with moderate swirl. The supersonic pressure probe is in the shape of a truncated cone with a flat nose opening for total pressure measurement and includes four holes on the cone surface for static pressure measurements. The objective of the present stochastic CFD study is to quantify the uncertainty in the pressure measurements and the Mach number due to the uncertainty in the cone angle, the nose diameter, and the location of the static pressure port on the cone surface. Each uncertain parameter was modeled as a uniform random variable with a specified range and mean value based on the tolerances supplied by the manufacturer. The uncertainty information for various output variables obtained with a second order polynomial chaos expansion fell within the confidence interval of the Latin Hypercube Monte Carlo statistics. The second order NIPC required only 20 CFD solutions to obtain the uncertainty inforu1ation, whereas the Monte Carlo simulations were performed with 1000 samples (CFD solutions), indicating the computational efficiency of the polynomial chaos approach. The relative variation in the Mach number due to the specified geometric uncertainty was found to be less than 1%. The sensitivity analysis obtained from the polynomial chaos expansions revealed that the Mach number is an order of magnitude more sensitive to the variation in the cone angle than the uncertainty in the other geometric variables.", "date": "2012-06-15", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2009-1129", "id_number": "CaltechAUTHORS:20200103-135336419", "isbn": "978-1-60086-973-0", "book_title": "47th AIAA Aerospace Sciences Meeting including The New Horizons Forum and Aerospace Exposition", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200103-135336419", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2009-1129", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2009-1129", "pub_year": "2012", "author_list": "Hosder, Serhat and Maddalena, Luca" }, { "id": "https://authors.library.caltech.edu/records/01wrq-rjq45", "eprint_id": 100344, "eprint_status": "archive", "datestamp": "2023-08-19 11:21:49", "lastmod": "2023-10-18 19:52:28", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Mallikarachchi-H-M-Y-C", "name": { "family": "Mallikarachchi", "given": "H. M. Y. C." } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Deployment Dynamics of Composite Booms with Integral Slotted Hinges", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2009 by H.M.Y.C. Mallikarachchi and S. Pellegrino. Published by American Institute of Aeronautics and Astronautics, Inc. \n\nPublished Online: 14 Jun 2012. \n\nWe thank Drs Ahmad Kueh, Julian Santiago Prowald and Michael Sutcliffe for helpful discussions. We are grateful to John Ellis (Hexcel, UK) for providing materials and Professor Chiara Daraio, Dr Alessandro Spadoni and Tian Lan for help with high speed imaging. HM thanks the Cambridge Commonwealth Trust and California Institute of Technology for financial support.\n\nPublished - Mallikarachchi_SDM09.pdf
", "abstract": "This paper considers a lightweight boom with an integral hinge consisting of a thin-walled tube made of carbon fibre reinforced plastic with two longitudinal slots. The dynamic deployment of this boom is studied both experimentally and by means of detailed finite-element simulations. The deployment of the boom can be divided into three phases: deployment; incomplete latching, buckling of the tape springs and large rotation of the boom; and vibration of the boom in latched configuration. The simulations show that the most critical phase is the second one, as the highest strains in both the fibres and the matrix occur at this stage. Through the simulations it is found that the deployment of the particular boom design studied in this paper is quite sensitive to the details of the gravity offload system.", "date": "2012-06-14", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2009-2631", "id_number": "CaltechAUTHORS:20191218-095027064", "isbn": "978-1-60086-975-4", "book_title": "50th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191218-095027064", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Cambridge Commonwealth Trust" }, { "agency": "Caltech" } ] }, "other_numbering_system": { "items": [ { "id": "2009-2631", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2009-2631", "primary_object": { "basename": "Mallikarachchi_SDM09.pdf", "url": "https://authors.library.caltech.edu/records/01wrq-rjq45/files/Mallikarachchi_SDM09.pdf" }, "pub_year": "2012", "author_list": "Mallikarachchi, H. M. Y. C. and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/cjv06-b3d96", "eprint_id": 100400, "eprint_status": "archive", "datestamp": "2023-08-19 11:21:58", "lastmod": "2023-10-18 19:55:40", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hosder-S", "name": { "family": "Hosder", "given": "Serhat" } }, { "id": "Maddalena-L", "name": { "family": "Maddalena", "given": "Luca" } } ] }, "title": "Efficient Uncertainty Quantification for the Design of a Supersonic Pressure Probe", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2009 by S. Hosder and L. Maddalena. Published by the American Institute of Aeronautics and Astronautics, Inc.", "abstract": "The Point-Collocation Non-Intrusive Polynomial Chaos (NIPC) method utilizing Euler CFD simulations has been applied to the stochastic analysis of a pressure probe designed for Mach number measurements in three-dimensional supersonic flows with moderate swirl.\nThe probe is in the shape of a truncated cone with a flat nose opening for total pressure measurement and includes four holes on the cone surface for static pressure measurements.\nThe present stochastic CFD study is performed to provide information for further refinement of the supersonic pressure probe design in the presence of geometric uncertainties and to quantify the variation in the pressure measurements and the Mach number due to the uncertainty in the cone angle, the nose diameter, and the location of the static pressure port on the cone surface. Each uncertain parameter was modeled as a uniform\nrandom variable with a specified range and mean value based on the tolerances supplied\nby the manufacturer. The uncertainty information for various output variables obtained\nwith a second order polynomial chaos expansion fell within the confidence interval of the\nLatin Hypercube Monte Carlo statistics. The second order NIPC required only 20 CFD\nsolutions to obtain the uncertainty information, whereas the Monte Carlo simulations were\nperformed with 1000 samples (CFD solutions), indicating the computational efficiency of\nthe polynomial chaos approach. The relative variation in the Mach number due to the\nspecified geometric uncertainty was found to be less than 1%. The sensitivity analysis\nobtained from the polynomial chaos expansions revealed that the Mach number is an order\nof magnitude more sensitive to the variation in the cone angle than the uncertainty in the\nother geometric variables. The stochastic results also showed that the uncertainty in the\ncone pressure measurement remains constant and minimum as long as the static pressure\nholes are located beyond 20% of the truncated cone surface length indicating the possibility\nfor a smaller-size probe design by moving the static pressure ports further upstream on\nthe cone surface.", "date": "2012-06-14", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2009-2285", "id_number": "CaltechAUTHORS:20191223-083508836", "isbn": "978-1-60086-975-4", "book_title": "50th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191223-083508836", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2009-2285", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2009-2285", "pub_year": "2012", "author_list": "Hosder, Serhat and Maddalena, Luca" }, { "id": "https://authors.library.caltech.edu/records/8r47x-j3708", "eprint_id": 100348, "eprint_status": "archive", "datestamp": "2023-08-19 11:21:54", "lastmod": "2023-10-18 19:52:40", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lopez-Jimenez-F", "name": { "family": "Lopez Jimenez", "given": "Francisco" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Folding of Thin Composite Structures with a Soft Matrix", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2009 by Francisco Lopez Jimenez and Sergio Pellegrino. Published by the American Institute of Aeronautics and Astronautics, Inc.\n\nPublished Online: 14 Jun 2012.\n\nPublished - folding_of_thin_composite_structures_with_a_soft_matrix.pdf
", "abstract": "The paper presents detailed micromechanical finite element simulations of composite materials with soft materials undergoing large macroscopic bending deformation. The simulations allow the study of fibre microbuckling under bending, including the kinematics of the fibres, as well as the strains in the matrix. These simulations lead to a simple analytical model that allows a quite accurate estimation of the buckling wavelength. It also provides the moment-curvature relationship. Finally, the model is also able to predict the maximum strain in the fibres for a given curvature.", "date": "2012-06-14", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2009-2633", "id_number": "CaltechAUTHORS:20191218-112129907", "isbn": "978-1-60086-975-4", "book_title": "50th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191218-112129907", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2009-2633", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2009-2633", "primary_object": { "basename": "folding_of_thin_composite_structures_with_a_soft_matrix.pdf", "url": "https://authors.library.caltech.edu/records/8r47x-j3708/files/folding_of_thin_composite_structures_with_a_soft_matrix.pdf" }, "pub_year": "2012", "author_list": "Lopez Jimenez, Francisco and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/p82e6-tge49", "eprint_id": 98712, "eprint_status": "archive", "datestamp": "2023-08-19 11:18:02", "lastmod": "2023-10-18 17:35:25", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kwok-Kawai", "name": { "family": "Kwok", "given": "Kawai" }, "orcid": "0000-0001-6876-4267" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Large Strain Viscoelastic Model for Balloon Film", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2012 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 4 Jun 2012.", "abstract": "This paper presents a constitutive model capable of predicting the anisotropic viscoelastic behavior of balloon film subject to large strains and cyclic loading. The model is based on the free volume theory of nonlinear viscoelasticity enhanced with a switching rule for treating loading and unloading differently. The model has been implemented in the finite element analysis program Abaqus/Standard and the results have been compared with experiments on the balloon film StratoFilm 420 under biaxial tension and shear.", "date": "2012-06-04", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2011-6939", "id_number": "CaltechAUTHORS:20190918-093409950", "isbn": "978-1-60086-941-9", "book_title": "11th AIAA Aviation Technology, Integration, and Operations (ATIO) Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190918-093409950", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2011-6939", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2011-6939", "pub_year": "2012", "author_list": "Kwok, Kawai and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/4mcdv-8th68", "eprint_id": 98710, "eprint_status": "archive", "datestamp": "2023-08-19 11:17:59", "lastmod": "2023-10-18 17:35:20", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "S." }, "orcid": "0000-0001-9373-3278" }, { "id": "Deng-Xiaowei", "name": { "family": "Deng", "given": "X." } } ] }, "title": "A Technique to Predict Clefting of Lobed Super-Pressure Balloons", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2012 American Institute of Aeronautics and Astronautics. \n\nPublished Online: 4 Jun 2012.", "abstract": "Lobed super-pressure balloons have shown a tendency to deploy into unexpected asymmetric shapes, hence their design has to strike a balance between the lowest stresses achieved by increasing lobing and the risk of incomplete deployment. This paper proposes a computational clefting test that can be applied to any given balloon design. The test consists in setting up the balloon in its symmetrically inflated configuration, then breaking the symmetry of this shape by artificially introducing a clefting imperfection, and finally determining the equilibrium shape of the balloon. Wrinkling of the balloon film and frictionless contact are included in the computation. The clefting test is applied successfully to three 27 m diameter super-pressure balloons that have been tested indoors by NASA, of which one had remained clefted when it was inflated and the other two had deployed completely.", "date": "2012-06-04", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2011-6830", "id_number": "CaltechAUTHORS:20190918-090257435", "isbn": "978-1-60086-941-9", "book_title": "11th AIAA Aviation Technology, Integration, and Operations (ATIO) Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190918-090257435", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2011-6830", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2011-6830", "pub_year": "2012", "author_list": "Pellegrino, S. and Deng, X." }, { "id": "https://authors.library.caltech.edu/records/mkyh2-73153", "eprint_id": 71862, "eprint_status": "archive", "datestamp": "2023-08-19 10:51:18", "lastmod": "2023-10-23 17:16:48", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lai-William", "name": { "family": "Lai", "given": "William" } }, { "id": "Bastawros-A-F", "name": { "family": "Bastawros", "given": "Ashraf F." } }, { "id": "Hong-Wei", "name": { "family": "Hong", "given": "Wei" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Fabrication and analysis of planar dielectric elastomer actuators capable of complex 3-D deformation", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2012 IEEE. \n\nDate Added to IEEE Xplore: 28 June 2012. \n\nThis work is supported by U.S. Army Research Office under Award No W911NF-10-1-0296.", "abstract": "A new design for a dielectric elastomer actuator with geometrically confining reinforcements is presented. The resulting structures enable complex 3-dimentional motion without the need of the membrane prestretch. An in situ imaging system is used to capture the complex deformation pattern to evaluate the surface curvatures. The deformation mode is analyzed analytically using the bi-laminate theory to explore the actuator performance and further develop analytical model amenable for control strategies. A finite element material model is also developed to couple the applied electric field to the resulting deformation. The model is used to analyze more complex deformation patterns. The proposed confining reinforcements would enable the development of flexible wings for agile aerial robotics and compliant continuum robotics, utilizing the proposed deformation mechanisms to provide controllable many degrees of freedom.", "date": "2012-05", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "4968-4973", "id_number": "CaltechAUTHORS:20161109-080512793", "isbn": "978-1-4673-1405-3", "book_title": "2012 IEEE International Conference on Robotics and Automation", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161109-080512793", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Army Research Office (ARO)", "grant_number": "W911NF-10-1-0296" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/ICRA.2012.6225079", "pub_year": "2012", "author_list": "Lai, William; Bastawros, Ashraf F.; et el." }, { "id": "https://authors.library.caltech.edu/records/jz1p3-ara37", "eprint_id": 98220, "eprint_status": "archive", "datestamp": "2023-08-19 10:42:13", "lastmod": "2023-10-18 17:09:46", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Yamamoto-Namiko", "name": { "family": "Yamamoto", "given": "Namiko" } }, { "id": "Thevamaran-R", "name": { "family": "Thevamaran", "given": "Ramathasan" }, "orcid": "0000-0001-5058-6167" }, { "id": "Daraio-C", "name": { "family": "Daraio", "given": "Chiara" }, "orcid": "0000-0001-5296-4440" } ] }, "title": "Dynamic Behavior of Periodic Structures Consisting of Vertically Aligned Carbon Nanotubes and Rigid Interlayers", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2012 American Institute of Aeronautics and Astronautics.", "abstract": "We assembled novel periodic structures by alternating aligned carbon nanotube (CNT) discs and polycarbonate cylindrical particles for stress damping applications. CNTs are known to present a nonlinear, hysteretic mechanical behavior in compression with the ability to recover from large strains. Furthermore, CNTs are generally more lightweight and thermally stable than currently existing viscoelastic polymers. We test the dynamic response of these CNT/polycarbonate multilayer systems excited by an impact. The response of these systems is found to be highly nonlinear and tunable by variation of the static precompression applied. We studied the wave propagation properties and dissipation in these systems and found that the presence of CNTs improves the energy damping properties of the system when compared with the one observed in polycarbonate particles alone. Such improvement was higher with smaller precompression loads. More detailed studies are required to understand the origin of the observed dynamic behavior.", "date": "2012-04-23", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2012-1389", "id_number": "CaltechAUTHORS:20190826-092412704", "isbn": "9781600869372", "book_title": "53rd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190826-092412704", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2012-1389", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2012-1389", "pub_year": "2012", "author_list": "Yamamoto, Namiko; Thevamaran, Ramathasan; et el." }, { "id": "https://authors.library.caltech.edu/records/d8mq3-p0a83", "eprint_id": 98306, "eprint_status": "archive", "datestamp": "2023-08-19 10:42:33", "lastmod": "2023-10-18 17:14:20", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kwok-Kawai", "name": { "family": "Kwok", "given": "Kawai" }, "orcid": "0000-0001-6876-4267" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Micromechanical modeling of deployment and shape recovery of thin-walled viscoelastic composite space structures", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2012 by Kawai Kwok and Sergio Pellegrino. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission. \n\nThe authors are grateful to Professor Wolfgang Knauss at the California Institute of Technology for helpful comments and Gary Patz at Patz Materials Technologies for providing materials used for the present study. Financial support for Kawai Kwok by the Croucher Foundation is acknowledged.\n\nAccepted Version - Full.pdf
", "abstract": "The first part of the paper presents an experimental study of the deployment and shape recovery of composite tape-springs after stowage at an elevated temperature. It is found that tape-springs deploy quickly and with a slight overshoot, but complete recovery takes place asymptotically over time. Stowage has the effect of slowing down both the shortterm deployment and long-term shape recovery. The second part of the paper presents a micromechanical finite element homogenization scheme to determine the effective viscoelastic properties of woven composite laminas. This solution scheme is employed in numerical simulations of deployment and shape recovery of composite tape-springs. The proposed micromechanical model predicts both the short-term deployment and long-term shape recovery response with close agreement to the experimental measurements.", "date": "2012-04-23", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2012-1910", "id_number": "CaltechAUTHORS:20190828-102318423", "isbn": "9781600869372", "book_title": "53rd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190828-102318423", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Croucher Foundation" } ] }, "other_numbering_system": { "items": [ { "id": "2012-1910", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2012-1910", "primary_object": { "basename": "Full.pdf", "url": "https://authors.library.caltech.edu/records/d8mq3-p0a83/files/Full.pdf" }, "pub_year": "2012", "author_list": "Kwok, Kawai and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/bqsjj-pey95", "eprint_id": 98305, "eprint_status": "archive", "datestamp": "2023-08-19 10:42:28", "lastmod": "2023-10-18 17:14:18", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Maqueda-I", "name": { "family": "Maqueda", "given": "I." } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "S." }, "orcid": "0000-0001-9373-3278" }, { "id": "Mejia-Ariza-J-M", "name": { "family": "Mejia-Ariza", "given": "J. M." } } ] }, "title": "Characterization of a high strain composite material", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2012 by Ignacio Maquadea and Sergio Pellegrino. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.\n\nThe material fabrication and characterization study presented in this paper was funded by NASA JPL under the SBIR-Phase 1 \"Thermally-Stable High Strain Deployable Structures\". The material development and manufacture of the Miura-ori composite lamina shown in Figure 1 were done under internal R&D funded by L'Garde, Inc. IM thanks the Fulbright Foundation for financial support.\n\nAccepted Version - Maqueda_2012.pdf
", "abstract": "L'Garde has designed and developed a high-strain composite material consisting of car- bon FIbers embedded in a silicone matrix. The behavior of this material is significantly different from standard composites and the paper presents special test methods to measure the properties of this material. It is found that rule of mixtures estimates are quite accurate for the longitudinal moduli in tension and bending, but less accurate for compression. The Poisson's ratio prediction is also not accurate. Regarding the strength of the composite, it is found that conservative predictions of tensile and compressive strengths can be obtained respectively from the Weibull distribution of the strength of a single fiber combined with a simple bundle theory, and the elastic fiber microbuckling stress.", "date": "2012-04-23", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2012-1909", "id_number": "CaltechAUTHORS:20190828-102318305", "isbn": "9781600869372", "book_title": "53rd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190828-102318305", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL" }, { "agency": "L'Garde, Inc." }, { "agency": "Fulbright Foundation" } ] }, "other_numbering_system": { "items": [ { "id": "2012-1909", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2012-1909", "primary_object": { "basename": "Maqueda_2012.pdf", "url": "https://authors.library.caltech.edu/records/bqsjj-pey95/files/Maqueda_2012.pdf" }, "pub_year": "2012", "author_list": "Maqueda, I.; Pellegrino, S.; et el." }, { "id": "https://authors.library.caltech.edu/records/0t9zy-4ff96", "eprint_id": 98222, "eprint_status": "archive", "datestamp": "2023-08-19 10:42:23", "lastmod": "2023-10-18 17:09:52", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Olson-G-M", "name": { "family": "Olson", "given": "Gina M." } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" }, { "id": "Costantine-J", "name": { "family": "Costantine", "given": "Joseph" } }, { "id": "Banik-J", "name": { "family": "Banik", "given": "Jeremy" } } ] }, "title": "Structural Architectures for a Deployable Wideband UHF Antenna", "ispublished": "unpub", "full_text_status": "public", "note": "This material is declared a work of the U.S. Government and is not subject to copyright protection in the United States.\n\nPublished - OlsonAIAA2012.pdf
", "abstract": "This paper explores concepts for a wideband deployable antenna suitable for small satellites. The general approach taken was to closely couple antenna theory and structural mechanics, to produce a deployable antenna that is considered efficient in both fields. Approaches that can be deployed using stored elastic strain energy have been favored over those that require powered actuators or environmental effects to enforce deployment. Two types of concepts were developed: thin shell structure and pantograph. These concepts cover four antenna topologies: crossed log periodic, conical log spiral, helical and quadrifilar helix. Of these, the conical log spiral antenna and the accompanying deployment concepts are determined to be the most promising approaches that warrant further study.", "date": "2012-04-23", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2012-1836", "id_number": "CaltechAUTHORS:20190826-092412894", "isbn": "9781600869372", "book_title": "53rd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190826-092412894", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2012-1836", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2012-1836", "primary_object": { "basename": "OlsonAIAA2012.pdf", "url": "https://authors.library.caltech.edu/records/0t9zy-4ff96/files/OlsonAIAA2012.pdf" }, "pub_year": "2012", "author_list": "Olson, Gina M.; Pellegrino, Sergio; et el." }, { "id": "https://authors.library.caltech.edu/records/v95p5-r5v15", "eprint_id": 98221, "eprint_status": "archive", "datestamp": "2023-08-19 10:42:18", "lastmod": "2023-10-18 17:09:49", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ning-Xin", "name": { "family": "Ning", "given": "Xin" }, "orcid": "0000-0002-9432-3665" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Design of Lightweight Structural Components for Direct Digital Manufacturing", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2012 by Xin Ning and Sergio Pellegrino. Published by the American Institute of Aeronautics and Astronautics with permission. \n\nWe thank Ted Nye for inspiring this research and gratefully acknowledge the financial support received from Northrop Grumman Aerospace Systems.\n\nPublished - NingAIAA2012.pdf
", "abstract": "The rapid growth in direct digital manufacturing technologies has opened the challenge of designing optimal micro-structures for high-performance components. Current topology optimization techniques do not work well for this type of problems and hence in this paper we propose a technique based on an implicit representation of the structural topology. The detailed microstructure is defined by a continuous variable, the size distribution field, defined over the design domain by chosen shape functions. We can optimize the structural topology by optimizing only the weights of the size distribution field and, for any given size distribution, we use standard meshing software to determine the actual detailed micro-structure. We have implemented the optimization loop using commercial CAD and FEA software, running under a genetic algorithm in MATLAB. Application this novel technique to the design of a sandwich beam has produced designs that are superior to any standard solid beam or even optimized truss structure.", "date": "2012-04-23", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2012-1807", "id_number": "CaltechAUTHORS:20190826-092412796", "isbn": "9781600869372", "book_title": "53rd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190826-092412796", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Northrop Grumman Aerospace Systems" } ] }, "other_numbering_system": { "items": [ { "id": "2012-1807", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2012-1807", "primary_object": { "basename": "NingAIAA2012.pdf", "url": "https://authors.library.caltech.edu/records/v95p5-r5v15/files/NingAIAA2012.pdf" }, "pub_year": "2012", "author_list": "Ning, Xin and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/zmhnv-3cg92", "eprint_id": 65050, "eprint_status": "archive", "datestamp": "2023-08-19 10:33:43", "lastmod": "2023-10-17 23:09:17", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Patterson-K", "name": { "family": "Patterson", "given": "Keith" } }, { "id": "Yamamoto-Namiko", "name": { "family": "Yamamoto", "given": "Namiko" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Thin deformable mirrors for a reconfigurable space telescope", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2012 AIAA. \n\nWe thank Eleftherious Gdoutos for establishing the early fabrication effort, and Dr. Harish Manohara (JPL) for providing access to JPL Microdevices Lab (MDL) cleanroom facilities for sample fabrication. We also thank Drs. Risaku Toda and Victor White (JPL) for assistance and advice on sample fabrication. The students in the Caltech Ae105 class contributed greatly to the mission telescope concept design, and we would like to acknowledge their efforts here. We also thank Dr. Jim Breckinridge for helpful discussions on telescope design, John Steeves, Prof. Chiara Daraio (Caltech), and Dr. Andrew Shapiro (JPL) also for help and advice regarding the fabrication of prototype mirrors. We also appreciate the fabrication facilities provided by the Molecular Materials Research Center and Kavli Nanoscience Institute at Caltech. Financial support from the Keck Institute of Space Studies (KISS) at Caltech is gratefully acknowledged.\n\nSubmitted - thin_deformable.pdf
", "abstract": "As part of a small satellite technology demonstration that will utilize autonomous assembly, reconfiguration, and docking technology to form the primary mirror for the mission's telescope payload, the mirror segments are required to modify and control their shape, in order to allow for imaging in different configurations. This paper focuses on the development of 10 cm diameter active lightweight mirrors. The current mirror design, control scheme, and fabrication methods are described, as well as experimental results on initial samples. The data demonstrates that the mirrors are capable of at least 100 microns of displacement during operation, and that fabrication on polished molds can result in high quality reflective surfaces.", "date": "2012-04", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2012-1668", "id_number": "CaltechAUTHORS:20160303-153240359", "isbn": "978-1-60086-937-2", "book_title": "53rd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160303-153240359", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Keck Institute for Space Studies (KISS)" } ] }, "other_numbering_system": { "items": [ { "id": "2012-1668", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "Keck-Institute-for-Space-Studies" }, { "id": "Kavli-Nanoscience-Institute" }, { "id": "GALCIT" } ] }, "doi": "10.2514/6.2012-1668", "primary_object": { "basename": "thin_deformable.pdf", "url": "https://authors.library.caltech.edu/records/zmhnv-3cg92/files/thin_deformable.pdf" }, "pub_year": "2012", "author_list": "Patterson, Keith; Yamamoto, Namiko; et el." }, { "id": "https://authors.library.caltech.edu/records/wj4ca-1fc84", "eprint_id": 30027, "eprint_status": "archive", "datestamp": "2023-08-19 10:24:48", "lastmod": "2024-01-13 05:51:52", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Brown-J-L", "name": { "family": "Brown", "given": "J. L." } }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "G." }, "orcid": "0000-0002-2912-0001" } ] }, "title": "High pressure Hugoniot measurements using Mach waves", "ispublished": "unpub", "full_text_status": "public", "keywords": "Hugoniot, Mach reflection, converging shocks", "note": "\u00a9 2012 American Institute of Physics. \n\nPublished online 29 March 2012. \n\nThe research support provided by the Caltech Center for the Predictive Modeling and Simulation of High-Energy Density Dynamic Response of Materials through the U.S. Department of Energy National Nuclear Security Administration under Award Number DE-FC52-08NA28613 is gratefully acknowledged.\n\nPublished - A9REF83.pdf
", "abstract": "Traditionally, most dynamic shock compression experiments are conducted using a plane one-dimensional wave of uniaxial strain. In this case, the evaluation of the equation of state is simplified due to the geometry, but the amplitude of the induced shock wave is limited by the magnitude of the input load. In an effort to dramatically increase the range of pressures that can be accessed by traditional loading methods, a composite target assembly is examined. The target consists of two concentric cylinders aligned with the axial direction parallel to the loading. The target is designed such that on initial loading, the outer cylinder will have a higher shock velocity than the inner material of interest. Conically converging shocks will be generated at the interface between the two materials due to the impedance mismatch. Upon convergence, an irregular reflection occurs and the conical analog of a Mach reflection develops. The Mach reflection will grow until it reaches a steady state, at which point the wave configuration becomes self similar. The resulting high pressure Hugoniot state can then be measured using velocity interferometry and impedance matching. The technique is demonstrated using a planar mechanical impact generated by a powder gun to study the shock response of copper. Two systems are examined which utilize either a low impedance (6061-T6 aluminum) or a high impedance (molybdenum) outer cylinder. A multipoint VISAR experiment will be presented to validate the technique, and will be compared to numerical simulations. The feasibility of measuring an entire Hugoniot curve using full field velocity interferometry (ORVIS) will also be discussed.", "date": "2012-03-29", "date_type": "published", "publisher": "American Institute of Physics", "place_of_pub": "Melville, NY", "pagerange": "485-488", "id_number": "CaltechAUTHORS:20120409-074212038", "isbn": "978-0-7354-1006-0", "book_title": "2011 Shock Compression of Condensed Matter", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120409-074212038", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Department of Energy (DOE) National Nuclear Security Administration", "grant_number": "DE-FC52-08NA28613" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Elert-M-L", "name": { "family": "Elert", "given": "Mark L." } } ] }, "doi": "10.1063/1.3686323", "primary_object": { "basename": "A9REF83.pdf", "url": "https://authors.library.caltech.edu/records/wj4ca-1fc84/files/A9REF83.pdf" }, "pub_year": "2012", "author_list": "Brown, J. L. and Ravichandran, G." }, { "id": "https://authors.library.caltech.edu/records/kqeqz-18608", "eprint_id": 64705, "eprint_status": "archive", "datestamp": "2023-08-19 10:09:35", "lastmod": "2023-10-17 21:36:44", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Brophy-J-R", "name": { "family": "Brophy", "given": "John R." } }, { "id": "Friedman-L", "name": { "family": "Friedman", "given": "Louis" } }, { "id": "Culick-F-E-C", "name": { "family": "Culick", "given": "Fred" } } ] }, "title": "Asteroid retrieval feasibility", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Earth, Extraterrestrial measurements, Laser radar, Object recognition, Orbits, Space vehicles", "note": "\u00a9 2012 IEEE. \n\nThe research described in this paper was sponsored by the Keck Institute for Space Studies (KISS) and was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. \n\nThe people and organizations listed below participated in the KISS-sponsored study. It is their work that is summarized in this paper and the authors gratefully acknowledge their contributions. In addition, the Collaborative Modeling for Parametric Assessment of Space Systems (COMPASS) team at NASA GRC performed a study of the Asteroid Retrieval Mission concept resulting in conceptual flight system configuration and mass estimate. Their work is also gratefully acknowledged by the authors.", "abstract": "This paper describes the interim results of a study sponsored by the Keck Institute for Space Studies to investigate the feasibility of identifying, robotically capturing, and returning an entire Near-Earth Asteroid (NEA) to the vicinity of the Earth by the middle of the next decade. The feasibility hinges on finding an overlap between the smallest NEAs that can be reasonably discovered and characterized and the largest NEAs that can be captured and transported in a reasonable flight time. This overlap appears to be centered on NEAs with a nominal diameter of roughly 7 m corresponding to masses in the range of 250,000 kg to 1,000,000 kg. Trajectory analysis based on asteroid 2008HU4 suggests that such an asteroid could be returned to a high-Earth orbit using a single Atlas V-class launch vehicle and a 40-kW solar electric propulsion system by 2026. The return of such an object could serve as a testbed for human operations in the vicinity of an asteroid. It would provide a wealth of scientific and engineering information and would enable detailed evaluation of its resource potential, determination of its internal structure and other aspects important for planetary defense activities.", "date": "2012-03", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "1-16", "id_number": "CaltechAUTHORS:20160223-163750505", "isbn": "978-1-4577-0556-4", "book_title": "2012 IEEE Aerospace Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160223-163750505", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Keck Institute for Space Studies (KISS)" } ] }, "local_group": { "items": [ { "id": "Keck-Institute-for-Space-Studies" }, { "id": "GALCIT" } ] }, "doi": "10.1109/AERO.2012.6187031", "pub_year": "2012", "author_list": "Brophy, John R.; Friedman, Louis; et el." }, { "id": "https://authors.library.caltech.edu/records/kjrbw-h2e32", "eprint_id": 98311, "eprint_status": "archive", "datestamp": "2023-08-19 09:32:11", "lastmod": "2023-10-18 17:14:31", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Alexeenko-Alina-A", "name": { "family": "Alexeenko", "given": "A. A." } }, { "id": "Kulakhmetov-Marat", "name": { "family": "Kulakhmetov", "given": "M." } }, { "id": "Weaver-Andrew", "name": { "family": "Weaver", "given": "A." } }, { "id": "Slipchenko-M-N", "name": { "family": "Slipchenko", "given": "M. N." } }, { "id": "Mihaly-J-M", "name": { "family": "Mihaly", "given": "J." } }, { "id": "Adams-Marc", "name": { "family": "Adams", "given": "M." } }, { "id": "Rosakis-A-J", "name": { "family": "Rosakis", "given": "A." }, "orcid": "0000-0003-0559-0794" } ] }, "title": "Feasibility of Non-Equilibrium Hypersonic Flow Measurements at the Small Particle Hypervelocity Impact Range", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2012 by the authors. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.", "abstract": "Currently used hypersonic flow models, such as high-enthalpy reaction and energy relaxation rates, are based on experiments conducted at relatively low flow enthalpies and are highly uncertain. This paper presents analysis of the feasibility of calibrating hypersonic flow parameters using free-flight experiments at the Small Particle Hypervelocity Range (SPHIR) at Caltech/JPL. Chemically reacting, nonequilibrium flows around a 2-mm diameter spherical projectile are modeled using the Direct Simulation Monte Carlo (DSMC) method. The flowfields generated by DSMC simulations are used to calculate emission spectra in order to determine the observable radiation in UV/vis spectral range. Bayesian calibration and generalized polynomial chaos expansion (gPCE) techniques are used to assess the sensitivity of observable flow properties to key reaction rates. These techniques are then used to predict how experimental resolution would affect the uncertainty in the calibrated parameters.", "date": "2012-01-09", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2012-0596", "id_number": "CaltechAUTHORS:20190828-102318872", "isbn": "9781600869365", "book_title": "50th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190828-102318872", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2012-0596", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2012-596", "pub_year": "2012", "author_list": "Alexeenko, A. A.; Kulakhmetov, M.; et el." }, { "id": "https://authors.library.caltech.edu/records/3a9gk-d4r56", "eprint_id": 50073, "eprint_status": "archive", "datestamp": "2023-08-19 09:27:54", "lastmod": "2023-10-17 22:29:25", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Swantek-A-B", "name": { "family": "Swantek", "given": "A. B." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "J. M." } } ] }, "title": "Heat Transfer on a Double Wedge Geometry in Hypervelocity Air and Nitrogen Flows", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2012 by Andrew B Swantek. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.\n\nAIAA 2012-0284.\n\nThis work was funded through the U.S. Air Force Office of Scientific Research (award FA 9550-11-1-0129)\nwith Dr. John Schmisseur as program manager. Invaluable assistance with thermocouple instrumentation\nand data processing was provided by William Flaherty at Illinois. We are very grateful to Prof. Hans\nHornung and the Caltech T5 group for the generous sharing of their thermocouple design and expertise.\n\nPublished - 385392.pdf
", "abstract": "We investigate shock wave/boundary-layer interaction and resulting heat transfer in hypervelocity double wedge \nflows. An expansion tube is used to generate air and nitrogen flows with stagnation enthalpies ranging from 2.1-8.0 MJ/kg and Mach numbers from 4-7.\nThe range of free stream conditions were selected to investigate the impact of thermochemical effects by i) systematically varying the chemical composition from nitrogen to air\nwhile maintaining constant the stagnation enthalpy or the Mach number, and ii) varying\nthe stagnation enthalpy. Flow features are visualized with schlieren photography, and heat\ntransfer is measured using fast response coaxial thermocouples. Data are presented for\nboth nitrogen and air test conditions with eight cases in total. Current results indicate\nsignificantly different behavior in \nflows with enthalpies as low as 4 MJ/kg between air and\nnitrogen test conditions.", "date": "2012-01", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "id_number": "CaltechAUTHORS:20140926-141541877", "isbn": "9781622760671", "book_title": "50th AIAA aerospace sciences meeting including the new horizons forum and aerospace exposition 2012", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140926-141541877", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA 9550-11-1-0129" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2012-284", "primary_object": { "basename": "385392.pdf", "url": "https://authors.library.caltech.edu/records/3a9gk-d4r56/files/385392.pdf" }, "pub_year": "2012", "author_list": "Swantek, A. B. and Austin, J. M." }, { "id": "https://authors.library.caltech.edu/records/fmmt6-rp640", "eprint_id": 50074, "eprint_status": "archive", "datestamp": "2023-08-19 09:27:58", "lastmod": "2023-10-17 22:29:27", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Fontaine-R-A", "name": { "family": "Fontaine", "given": "Ryan A." } }, { "id": "Bobbitt-B", "name": { "family": "Bobbitt", "given": "Brock" } }, { "id": "Elliott-G-S", "name": { "family": "Elliott", "given": "Gregory S." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "Joanna M." } }, { "id": "Freund-J-B", "name": { "family": "Freund", "given": "Jonathan B." } } ] }, "title": "Design and Demonstration of a New Small-Scale Jet Noise Experiment", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2012 by Ryan A. Fontaine. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.\n\nAIAA 2012-0682.\n\nThis work was funded through Gulfstream Aerospace Corporation and Rolls-Royce (SRA 2008-03199).\nThe authors thank Shweta Sharma for her work on the preliminary design of the facility, Bill Flaherty, Andrew\nKnisely, and Andrew Swantek for their help during the chamber construction phase, Dr. James Bridges, Dr.\nPeter Jordan, and Prof. Mo Samimy for generously sharing of their experience with such facilities as we were\ndeveloping ours, and Prof. Larry Ukeiley for providing raw data for Figure 12.\n\nPublished - 385394.pdf
", "abstract": "A facility capable of acoustic and velocity field measurements of high-speed jets has\nrecently been built and tested. The anechoic chamber that houses the jet has a 2.1 m\n\u00d7 2.3 m \u00d7 2.5 m wedge tip to wedge tip working volume. We aim to demonstrate that\nuseful experiments can be performed in such a relatively small facility for a substantially\nlower cost than in larger facility. Rapid prototyping allows for quick manufacturing of both\nsimple and complex geometry nozzles. Sideline and 30\u00b0 downstream acoustic measurements\nbetween 400 Hz and 100 kHz agree well with accepted results. Likewise, nozzle exit-plane\ndata obtained using particle image velocimetry are in good agreement with other studies.", "date": "2012-01", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "id_number": "CaltechAUTHORS:20140926-143501845", "isbn": "9781622760671", "book_title": "50th AIAA aerospace sciences meeting including the new horizons forum and aerospace exposition 2012", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140926-143501845", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gulfstream Aerospace Corporation" }, { "agency": "Rolls-Royce", "grant_number": "SRA 2008-03199" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2012-682", "primary_object": { "basename": "385394.pdf", "url": "https://authors.library.caltech.edu/records/fmmt6-rp640/files/385394.pdf" }, "pub_year": "2012", "author_list": "Fontaine, Ryan A.; Bobbitt, Brock; et el." }, { "id": "https://authors.library.caltech.edu/records/e6c0f-z8102", "eprint_id": 50116, "eprint_status": "archive", "datestamp": "2023-08-19 09:16:41", "lastmod": "2023-10-17 22:31:38", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Flaherty-W", "name": { "family": "Flaherty", "given": "W." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "J. M." } } ] }, "title": "Experimental Investigation of Mechanical Distortions to Hypersonic Boundary Layers", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2012 Springer.\n\nThe authors gratefully acknowledge researchers at ISSI, Prof. G.S. Elliott,\nand the support of AFOSR FA9550-08-1-0172 with Dr. John Schmisseur as Program\nManager and AFRL FA8650-10-M-3023 with Dr. Daniel Tejtel as Program Manager.", "abstract": "Destabilization of the boundary layer in hypervelocity flight can significantly increase the surface heat flux. For example, a stretch of concave surface curvature has been found to increase the skin friction by 125 % [1]. Goertler vortices were found to cause fluctuations in heat transfer of 20-30% in a Mach 7.1 flow over a concave compression ramp [2]. Ekoto et al. carried out an extensive study of global (adverse, favorable, and combined pressure gradients) and local (due to surface roughness) distortions in a turbulent hypersonic boundary layer [3]. Building on these works, we experimentally investigate the structure and breakdown of imposed vortex structures in a laminar hypervelocity boundary layer over a flat plate, and linear and curved compression surfaces.", "date": "2012", "date_type": "published", "publisher": "Springer", "place_of_pub": "Berlin", "pagerange": "675-680", "id_number": "CaltechAUTHORS:20140930-094655581", "isbn": "978-3-642-25687-5", "book_title": "28th International Symposium on Shock Waves", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140930-094655581", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-08-1-0172" }, { "agency": "Air Force Research Laboratory (AFRL)", "grant_number": "FA8650-10-M-3023" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Konstantinos-K", "name": { "family": "Konstantinos", "given": "Kontis" } } ] }, "pub_year": "2012", "author_list": "Flaherty, W. and Austin, J. M." }, { "id": "https://authors.library.caltech.edu/records/frv6k-hbx56", "eprint_id": 50115, "eprint_status": "archive", "datestamp": "2023-08-19 09:16:33", "lastmod": "2023-10-17 22:31:31", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Khokhlov-A-M", "name": { "family": "Khokhlov", "given": "A." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "J. M." } }, { "id": "Bacon-C", "name": { "family": "Bacon", "given": "C." } }, { "id": "Clifford-B", "name": { "family": "Clifford", "given": "B." } }, { "id": "Knisely-A", "name": { "family": "Knisely", "given": "A." } }, { "id": "Aithal-S", "name": { "family": "Aithal", "given": "S." } } ] }, "title": "Simulations of Reflected Shock Bifurcation in a Square Channel", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2012 Springer.\n\nThe authors gratefully acknowledge the joint funding provided by the ASCR and\nthe BES divisions of the DOE Office of Science DE-SC0002594 with managers\nDr Mark Pederson, Dr Randall Laviolette (current), Dr Lali Chatterjee (former),\nand the resources of the Argonne Leadership Computing Facility under DE-AC02-\n06CH11357. AK acknowledges partial NSF support under AST-0709181 and TGAST090074\ngrants.", "abstract": "Reflected shock interaction with an incoming boundary layer produces a complex, unsteady, three-dimensional flow field. Shock bifurcation, formation of recirculation bubbles, and turbulent jets are all observed and have been extensively studied experimentally ([1, 2, 3, 4, 5, 6]). The details of the reflection are known to depend on the inflow conditions, including the boundary layer behind the incident shock, and the wall boundary conditions. Reflected shock tube experiments have been conducted in shock tubes with both circular and rectangular cross-sections. There is experimental and numerical evidence that the bifurcated structure is substantially more complex near the corners of a rectangular tube as compared to the bifurcated structure on the centerline of a rectangular tube or in a round tube ([7, 8]). In this study, we present and analyze results of three-dimensional Navier-Stokes direct numerical simulations (DNS) of shock reflection in a square channel for three different incident shock Mach numbers. Key features of the present simulations are very high resolution inside the boundary layer and temperature-dependent material and transport properties. We compare and contrast our results as a function of the incident shock Mach number with the existing theoretical model of Mark [1]. The simulations reveal additional flow features in the recirculation and corner regions that are not captured by the model.", "date": "2012", "date_type": "published", "publisher": "Springer", "place_of_pub": "Berlin", "pagerange": "625-630", "id_number": "CaltechAUTHORS:20140930-093621384", "isbn": "978-3-642-25687-5", "book_title": "28th International Symposium on Shock Waves", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140930-093621384", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Department of Energy (DOE)", "grant_number": "DE-SC0002594" }, { "agency": "Department of Energy (DOE)", "grant_number": "DE-AC02-06CH11357" }, { "agency": "NSF", "grant_number": "AST-0709181" }, { "agency": "NSF", "grant_number": "TG-AST090074" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Konstantinos-K", "name": { "family": "Konstantinos", "given": "Kontis" } } ] }, "pub_year": "2012", "author_list": "Khokhlov, A.; Austin, J. M.; et el." }, { "id": "https://authors.library.caltech.edu/records/8n3qf-j8w70", "eprint_id": 103360, "eprint_status": "archive", "datestamp": "2023-08-22 04:32:58", "lastmod": "2023-10-20 15:57:39", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "Hans G." }, "orcid": "0000-0002-4903-8419" }, { "id": "Schramm-J-M", "name": { "family": "Schramm", "given": "Jan Martinez" } }, { "id": "Hannemann-K", "name": { "family": "Hannemann", "given": "Klaus" } } ] }, "title": "Sonic Line and Stand-Off Distance on Re-entry Capsule Shapes", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Density Ratio; Standoff Distance; Sonic Line; Oblate Ellipsoid; Sharp Cone", "note": "\u00a9 2012 Springer-Verlag Berlin Heidelberg.", "abstract": "In hypersonic flow over a sphere, the shock wave stand\u2013off distance is related to the density ratio by\n\u0394/r = 0.78\u03c1\u221e/\u03c1,\nwhere \u0394 is the stand\u2013off distance, r is the sphere radius, \u03c1\u221e\u2009 is the free\u2013stream density and \u03c1 is the average density along the stagnation streamline, see e. g., Hornung [1]. For a sharp cone of a given angle, the stand\u2013off distance increases linearly with \u03c1\u221e/\u03c1 from a critical onset point and is scaled by the base radius R of the cone, see e. g., Leyva [2]. For a spherically blunted cone, one may therefore expect a transition to occur between sphere behavior and sharp cone behavior. This would be undesirable for stability and heat\u2013flux reasons. A possibly more benign shape is an oblate ellipsoid, as suggested by Brown [5]. We study features of such flows on the basis of perfect\u2013gas computations. Since the density ratio is very sensitive to reaction rate in flows with vibrational and chemical relaxation, these phenomena are very important in entry of vehicles into atmospheres such as that of Mars. The computations are therefore extended to include the effects of reacting CO\u2082 flows.", "date": "2012", "date_type": "published", "publisher": "Springer", "place_of_pub": "Berlin", "pagerange": "605-611", "id_number": "CaltechAUTHORS:20200520-132230185", "isbn": "978-3-642-25684-4", "book_title": "28th International Symposium on Shock Waves", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200520-132230185", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Kontis-K", "name": { "family": "Kontis", "given": "Konstantinos" } } ] }, "doi": "10.1007/978-3-642-25685-1_92", "pub_year": "2012", "author_list": "Hornung, Hans G.; Schramm, Jan Martinez; et el." }, { "id": "https://authors.library.caltech.edu/records/vf97z-nkj94", "eprint_id": 72433, "eprint_status": "archive", "datestamp": "2023-08-19 09:18:32", "lastmod": "2024-01-13 20:21:00", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Dorothy-M-R", "name": { "family": "Dorothy", "given": "Michael" } }, { "id": "Paranjape-A-A", "name": { "family": "Paranjape", "given": "Aditya A." }, "orcid": "0000-0002-3164-3215" }, { "id": "Kuang-P-Daniel", "name": { "family": "Kuang", "given": "P. Daniel" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Towards Bio-Inspired Robotic Aircraft: Control Experiments on Flapping and Gliding Flight", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2012 American Institute of Aeronautics and Astronautics, Inc. \n\nThis project was supported by the Air Force Office of Scientific Research under the Young Investigator Award Program (Grant No. FA95500910089) monitored by W. Larkin. The authors would like to thank the following students from the University of Illinois at Urbana\u2013Champaign: Joe Kim and Nihar Gandhi.", "abstract": "THERE is a growing interest in the aerospace community in the development of robotic micro aerial vehicles (MAVs) to learn and mimic avian flight. MAVs fly in low-Reynolds-number regimes of 103 to 105, which corresponds to that of small birds or bats [1]. MAVs with wings equipped with multiple degrees of freedom such as flapping, wing twist, and sweep provide greater payload capability than insect-like MAVs and greater maneuverability than conventional fixed-wing aircraft. These MAVs can be used for intelligence gathering, surveillence, and reconnaissance\nmissions in tightly constrained spaces such as forests and urban areas. Advances in actuators and control systems have led to development and analysis of articulated and flapping MAVs inspired by animals [2\u20135]. Birds and bats achieve remarkable stability and perform agile manuevers using their wings very effectively [2]. One of the goals of reverse-engineering animal flight is to learn more about the various aspects of avian flight such as stability, maneuverability, and control from the dynamics of MAV.", "date": "2012", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics (AIAA)", "place_of_pub": "Reston, VA", "pagerange": "1-31", "id_number": "CaltechAUTHORS:20161130-094235795", "isbn": "978-1-60086-897-9", "book_title": "Advances in Intelligent and Autonomous Aerospace Systems", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161130-094235795", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA95500910089" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Valasek-J", "name": { "family": "Valasek", "given": "John" } } ] }, "doi": "10.2514/5.9781600868962.0001.0032", "pub_year": "2012", "author_list": "Dorothy, Michael; Paranjape, Aditya A.; et el." }, { "id": "https://authors.library.caltech.edu/records/jbec1-ad440", "eprint_id": 103362, "eprint_status": "archive", "datestamp": "2023-08-22 04:33:06", "lastmod": "2023-10-20 15:57:54", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Karl-S", "name": { "family": "Karl", "given": "Sebastian" } }, { "id": "Hannemann-K", "name": { "family": "Hannemann", "given": "Klaus" } }, { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "Hans G." }, "orcid": "0000-0002-4903-8419" } ] }, "title": "Bluntness Effects in Hypersonic Flow over Slender Cones and Wedges", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Hypersonic Flow; Nose Radius; Slender Body; Boundary Layer Transition; Stanton Number", "note": "\u00a9 2012 Springer-Verlag Berlin Heidelberg.", "abstract": "In hypersonic flow over slender bodies an important concern is the influence of nose bluntness on the viscous boundary layer behavior. This is particularly important in the consideration of boundary layer instability and transition. There exist numerous treatments, both theoretical and experimental on this subject. Representative excellent examples are [1] and [2] In this study we use the deviation from sharp\u2013body theory of the heat flux distribution as obtained from computations of viscous perfect\u2013gas flow over blunted slender bodies at zero incidence to estimate the point where the body has forgotten that it is blunt.", "date": "2012", "date_type": "published", "publisher": "Springer", "place_of_pub": "Berlin", "pagerange": "691-696", "id_number": "CaltechAUTHORS:20200520-134452744", "isbn": "978-3-642-25684-4", "book_title": "28th International Symposium on Shock Waves", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200520-134452744", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Kontis-K", "name": { "family": "Kontis", "given": "Konstantinos" } } ] }, "doi": "10.1007/978-3-642-25685-1_105", "pub_year": "2012", "author_list": "Karl, Sebastian; Hannemann, Klaus; et el." }, { "id": "https://authors.library.caltech.edu/records/g4dqa-2na04", "eprint_id": 103348, "eprint_status": "archive", "datestamp": "2023-08-22 04:32:17", "lastmod": "2023-10-20 15:56:54", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Parziale-N-J", "name": { "family": "Parziale", "given": "N. J." }, "orcid": "0000-0001-9880-1727" }, { "id": "Jewell-J-S", "name": { "family": "Jewell", "given": "J. S." }, "orcid": "0000-0002-4047-9998" }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "J. E." }, "orcid": "0000-0003-3181-9310" }, { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "H. G." }, "orcid": "0000-0002-4903-8419" } ] }, "title": "Shock Tunnel Noise Measurement with Resonantly Enhanced Focused Schlieren Deflectometry", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Turbulent Boundary Layer; Acoustic Mode; Shock Layer; Slender Body; Shock Tunnel", "note": "\u00a9 2012 Springer-Verlag Berlin Heidelberg. \n\nThis work was sponsored by AFOSR/National Center for Hypersonic Research in Laminar-Turbulent Transition, for which Dr. John Schmisseur is the program manager. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the Air Force Office of Scientific Research or the U.S. Government.", "abstract": "The character of the boundary layer noise and ambient tunnel noise are of interest in the experimental study of laminar to turbulent transition. The instability mechanism in hypersonic flow over slender bodies is the acoustic mode. A number of investigations of flow over a slender cone in high-enthalpy facilities have been performed; however, measurements of the boundary layer noise and ambient tunnel noise have not been made. In cold hypersonic facilities the frequency range of the acoustic mode typically lies below 500 kHz; in high-enthalpy facilities, 5-20 MJ/kg, the most strongly amplified acoustic mode frequency is approximately 1-3 MHz. These high frequencies are well beyond the reach of the piezo-electric pressure transducers typically used in cold hypersonic facilities. A logical approach is to investigate the use of optical methods. Measurements of the boundary layer noise and ambient tunnel noise on a five degree half angle cone in the Caltech T5 hypervelocity shock tunnel are made with a single point focused schlieren system and a resonantly enhanced focused schlieren system.", "date": "2012", "date_type": "published", "publisher": "Springer", "place_of_pub": "Berlin", "pagerange": "747-752", "id_number": "CaltechAUTHORS:20200520-092004376", "isbn": "978-3-642-25687-5", "book_title": "28th International Symposium on Shock Waves", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200520-092004376", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Kontis-K", "name": { "family": "Kontis", "given": "Konstantinos" } } ] }, "doi": "10.1007/978-3-642-25688-2_113", "pub_year": "2012", "author_list": "Parziale, N. J.; Jewell, J. S.; et el." }, { "id": "https://authors.library.caltech.edu/records/k0vjy-h0h57", "eprint_id": 103343, "eprint_status": "archive", "datestamp": "2023-08-22 04:32:09", "lastmod": "2023-10-20 15:56:42", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Jewell-J-S", "name": { "family": "Jewell", "given": "J. S." }, "orcid": "0000-0002-4047-9998" }, { "id": "Leyva-I-A", "name": { "family": "Leyva", "given": "I. A." } }, { "id": "Parziale-N-J", "name": { "family": "Parziale", "given": "N. J." }, "orcid": "0000-0001-9880-1727" }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "J. E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "Effect of Gas Injection on Transition in Hypervelocity Boundary Layers", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Sound Absorption; Boundary Layer Transition; Stanton Number; Shock Tunnel; Transition Delay", "note": "\u00a9 2012 Springer-Verlag Berlin Heidelberg. \n\nThe authors thank Prof. Hans G. Hornung for invaluable guidance, advice, and other contributions on both the conception and execution of this work, and Mr. Bahram Valiferdowsi for his work with design, fabrication, and maintenance. This project was sponsored by the Air Force Office of Scientific Research under award number FA9550-10-1-0491, for which Dr. John Schmisseur is the program manager. The views expressed herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of AFOSR or the U.S. Government.", "abstract": "A novel method to delay transition in hypervelocity flows in air over slender bodies by injecting CO\u2082 into the boundary layer is presented. The dominant transition mechanism in hypersonic flow is the inviscid second (Mack) mode, which is associated with acoustic disturbanceswhich are trapped and amplified inside the boundary layer [8]. In dissociated CO\u2082-rich flows, nonequilibrium molecular vibration damps the acoustic instability, and for the high-temperature, high-pressure conditions associated with hypervelocity flows, the effect is most pronounced in the frequency bands amplified by the second mode [3].", "date": "2012", "date_type": "published", "publisher": "Springer", "place_of_pub": "Berlin", "pagerange": "735-740", "id_number": "CaltechAUTHORS:20200520-080459042", "isbn": "978-3-642-25687-5", "book_title": "28th International Symposium on Shock Waves", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200520-080459042", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-10-1-0491" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Kontis-K", "name": { "family": "Kontis", "given": "Konstantinos" } } ] }, "doi": "10.1007/978-3-642-25688-2_111", "pub_year": "2012", "author_list": "Jewell, J. S.; Leyva, I. A.; et el." }, { "id": "https://authors.library.caltech.edu/records/x120v-48x50", "eprint_id": 103353, "eprint_status": "archive", "datestamp": "2023-08-22 04:32:33", "lastmod": "2023-10-20 15:57:13", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "L\u00f3pez-Ortega-A", "name": { "family": "L\u00f3pez Ortega", "given": "A." } }, { "id": "Lombardini-M", "name": { "family": "Lombardini", "given": "M." } }, { "id": "Hill-D-J", "name": { "family": "Hill", "given": "D. J." } }, { "id": "Pullin-D-I", "name": { "family": "Pullin", "given": "D. I." } }, { "id": "Meiron-D-I", "name": { "family": "Meiron", "given": "D. I." }, "orcid": "0000-0003-0397-3775" } ] }, "title": "Shock Dynamics for Cylindrical/Spherical Converging Shocks in Elastic-Plastic Solids", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Mach Number; Plastic Region; Elastic Precursor; Eulerian Description; Converge Shock Wave", "note": "\u00a9 2012 Springer-Verlag Berlin Heidelberg. \n\nThis material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-FC52-08NA28613.", "abstract": "The study of cylindrical and spherical converging shock waves propagating in solid materials is relevant to the production of high temperatures and pressures in condensed matter with applications to inertial confinement fusion [1]. However, experimental studies conducted in the area are prone to complications derived from the measurement techniques available and the difficulty of producing a quasi-radially symmetric flow.", "date": "2012", "date_type": "published", "publisher": "Springer", "place_of_pub": "Berlin", "pagerange": "757-763", "id_number": "CaltechAUTHORS:20200520-110119540", "isbn": "978-3-642-25684-4", "book_title": "28th International Symposium on Shock Waves", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200520-110119540", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Department of Energy (DOE)", "grant_number": "DE-FC52-08NA28613" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Kontis-K", "name": { "family": "Kontis", "given": "Konstantinos" } } ] }, "doi": "10.1007/978-3-642-25685-1_115", "pub_year": "2012", "author_list": "L\u00f3pez Ortega, A.; Lombardini, M.; et el." }, { "id": "https://authors.library.caltech.edu/records/kcjvn-bnr12", "eprint_id": 50114, "eprint_status": "archive", "datestamp": "2023-08-19 09:16:26", "lastmod": "2023-10-17 22:31:27", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Swantek-A-B", "name": { "family": "Swantek", "given": "A. B." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "J. M." } } ] }, "title": "Separation Length Scaling in Hypervelocity Double Cone Air Flows", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2012 Springer.", "abstract": "A hallmark problem in the study of shockwave/boundary-layer interactions (SBLI) is the flow over a double cone. The system of conical shocks interact with a developing boundary layer to produce a region of flow separation. Due to the presence of real gas effects (defined here to mean any deviations from perfect gas behavior resulting from thermal transitions and chemical reactions), air simulations routinely fail to match experimental data at flow enthalpies greater than 6 MJ/kg [1]. The double cone flow has been identified as an exceptionally suitable model problem due to the sensitivity of the separation zone size and heat transfer rates to real gas effects [2]. Numerous researchers have investigated these flow fields both experimentally and computationally [3, 4, 5, 6, 7]. Many studies focus on the pressure and heat transfer distributions, in an effort to verify chemical and thermal models. The development of the shock system and separation zone has been investigated with varying configurations for both double cones [8] and double wedges [9].", "date": "2012", "date_type": "published", "publisher": "Springer", "place_of_pub": "Berlin", "pagerange": "669-674", "id_number": "CaltechAUTHORS:20140930-091412863", "isbn": "978-3-642-25687-5", "book_title": "28th International Symposium on Shock Waves", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140930-091412863", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Konstantinos-K", "name": { "family": "Konstantinos", "given": "Kontis" } } ] }, "pub_year": "2012", "author_list": "Swantek, A. B. and Austin, J. M." }, { "id": "https://authors.library.caltech.edu/records/24e0s-z6260", "eprint_id": 71645, "eprint_status": "archive", "datestamp": "2023-08-19 08:01:20", "lastmod": "2024-01-13 20:17:45", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Breckinridge-J-B", "name": { "family": "Breckinridge", "given": "James B." }, "orcid": "0000-0002-9488-098X" } ] }, "title": "Fourier Transforms By White-Light Interferometry: Michelson Stellar Interferometer Fringes", "ispublished": "unpub", "full_text_status": "public", "keywords": "rotational shear interferometry, astronomy, atmospheric optics, image processing, coherence theory & measurement, Michelson stellar interferometry, quasimonoplanatic", "note": "\u00a9 2011 SPIE Society of Photo-Optical Instrumentation Engineers. \n\nA white-light compensated rotational shear interferometer was developed with 90-degrees of shear. Theory was developed for the device and it was tested and applied to problems in optical information processing, astrophysics and atmospheric science. Since 1976 there have been over 200 scientific papers written using a coherence interferometer or rotational shear interferometer to acquire the data. \n\nThe author would like to thank Professor Sergio Pellegrino at CALECH and Dean Jim Wyant of the College of Optical Sciences for their support during the preparation of this manuscript. Deep appreciation goes to Professors Joseph Goodman and Jack Gaskill for their skill in making a complex subject clear and concise.\n\nPublished - 812206_1.pdf
", "abstract": "The white-light compensated rotational shear interferometer (coherence interferometer) was developed in an effort to study the spatial frequency content of passively illuminated white-light scenes in real-time and to image sources of astronomical interest at high spatial frequencies through atmospheric turbulence. This work was inspired by Professor Goodman's studies of the image formation properties of coherent (laser) illuminated transparencies. We discovered that real-time image processing is possible using white-light interferometry. The concept of a quasimonoplanatic approximation is introduced as a parallel to the quasimonochromatic approximation needed to describe the theory of Fourier transform spectrometers. This paper describes the coherence interferometer and reviews its image formation properties under the conditions of quasimonoplanacity and describes its development and its applications to physical optics, optical processing and astrophysics including the search for exoplanets.", "date": "2011-09-08", "date_type": "published", "publisher": "Society of Photo-Optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "Art. No. 812206", "id_number": "CaltechAUTHORS:20161101-072905392", "isbn": "978-0-81948-732-2", "book_title": "Tribute to Joseph W. Goodman", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161101-072905392", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Caulfield-H-J", "name": { "family": "Caulfield", "given": "H. John" } }, { "id": "Arsenault-H-H", "name": { "family": "Arsenault", "given": "Henri H." } } ] }, "doi": "10.1117/12.890537", "primary_object": { "basename": "812206_1.pdf", "url": "https://authors.library.caltech.edu/records/24e0s-z6260/files/812206_1.pdf" }, "pub_year": "2011", "author_list": "Breckinridge, James B." }, { "id": "https://authors.library.caltech.edu/records/c451j-zqp91", "eprint_id": 99102, "eprint_status": "archive", "datestamp": "2023-08-19 07:58:31", "lastmod": "2023-10-18 17:51:33", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lappas-V", "name": { "family": "Lappas", "given": "V." } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "S." }, "orcid": "0000-0001-9373-3278" }, { "id": "Guenat-H", "name": { "family": "Guenat", "given": "H." } }, { "id": "Straubel-M", "name": { "family": "Straubel", "given": "M." } }, { "id": "Steyn-H", "name": { "family": "Steyn", "given": "H." } }, { "id": "Kostopoulos-V", "name": { "family": "Kostopoulos", "given": "V." } }, { "id": "Sarris-E", "name": { "family": "Sarris", "given": "E." } }, { "id": "Takinalp-O", "name": { "family": "Takinalp", "given": "O." } }, { "id": "Wokes-S", "name": { "family": "Wokes", "given": "S." } }, { "id": "Bonnema-A", "name": { "family": "Bonnema", "given": "A." } } ] }, "title": "DEORBITSAIL: De-orbiting of satellites using solar sails", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2011 IEEE.", "abstract": "Historical practice of abandoning satellites at the end of their lifetime has left 8,500 tonnes of space waste in Low Earth Orbit. In the future, this practice must change. DEORBIT SAIL proposes an innovative system, allowing the safe de-orbiting of spacecraft at the end of their lifetime. Increasingly, space debris poses a risk for spacecraft. Hundreds of old satellites and thousands of pieces of space junk orbit Earth. Such debris collide, which in turn increases the amount of debris, as pieces of old satellites break of when hit by pieces of other retired spacecraft. Indeed, without a change of practice and the establishment of effective systems for safe de-orbiting of spacecraft at the end of their lifetime, it is estimated that the number of debris particles will grow with a growth rate in the order of 5 percent per year - a percentage which would raise over time as the number of possible collisions increase. The DEORBITSAIL project addresses this challenge, as it is set to develop a novel low cost low risk de-orbiting device for smaller spacecraft with a mass less than 500 kg that circulate Earth in Low Earth Orbit less than 900 km above us. DEORBITSAIL proposes to develop a 25 square metre Solar Sail, which would weight no more than 3 kg. Upon the end of its lifetime, the retired spacecraft would deploy this sail. Within 25 years, drag will drive the spacecraft downwards, taking the spacecraft home into Earth's atmosphere, where it would burn off safely. The 25 year de-orbiting period adheres to established recommendations by the European Space Agency (ESA), and deployed on all new small size spacecraft. DEORBITSAIL has the potential to reduce future debris by 70 percent. DEORBITSAIL is a fully funded space mission, sponsored by the EU FP7 program.", "date": "2011-09", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "1-3", "id_number": "CaltechAUTHORS:20191004-152131563", "isbn": "9781457718748", "book_title": "2011 2nd International Conference on Space Technology", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191004-152131563", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/icspt.2011.6064667", "pub_year": "2011", "author_list": "Lappas, V.; Pellegrino, S.; et el." }, { "id": "https://authors.library.caltech.edu/records/rc0fc-gce77", "eprint_id": 73160, "eprint_status": "archive", "datestamp": "2023-08-19 07:38:39", "lastmod": "2023-10-24 15:05:12", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Paranjape-A-A", "name": { "family": "Paranjape", "given": "Aditya A." }, "orcid": "0000-0002-3164-3215" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Krstic-Miroslav", "name": { "family": "Krstic", "given": "Miroslav" } } ] }, "title": "PDE Boundary Control for Flexible Articulated Aircraft Wings", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2011 by Aditya A. Paranjape, Soon-Jo Chung and Miroslav Krstic. Published by the American Institute of Aeronautics and Astronautics, Inc. \n\nThis project was supported in part by the Air Force Office of Scientific Research (AFOSR) under the Young Investigator Award Program (Grant No. FA95500910089) and the U.S. Army Research Office (ARO) under Award No W911NF-10-1-0296. The original problem of articulated wing aircraft was posed by Dr. Gregg Abate (AFRL).\n\nPublished - PDEcontrol.pdf
", "abstract": "The paper considers a boundary control formulation for PDEs with a system output given by a spatial integral of weighted functions of the state. This formulation is directly applicable to the control of an aircraft with articulated exible wings, in which case the output of interest is a net aerodynamic force or moment. Flexible wings can be controlled via actuation at the root or the tip. The problem of beam twist is analysed in detail to\nillustrate the formulation, and it shown that the control law ensures that the error between the desired output signal and the actual output signal decreases exponentially to an uniform ultimate bound. Stability of the closed loop system is proved by Lyapunov techniques. The formulation is demonstrated by simulations.", "date": "2011-08", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics (AIAA)", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2011-6486", "id_number": "CaltechAUTHORS:20161222-122638313", "isbn": "978-1-60086-952-5", "book_title": "AIAA Guidance, Navigation, and Control Conference 2011", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161222-122638313", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA95500910089" }, { "agency": "Army Research Office (ARO)", "grant_number": "W911NF-10-1-0296" } ] }, "other_numbering_system": { "items": [ { "id": "2011-6486", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2011-6486", "primary_object": { "basename": "PDEcontrol.pdf", "url": "https://authors.library.caltech.edu/records/rc0fc-gce77/files/PDEcontrol.pdf" }, "pub_year": "2011", "author_list": "Paranjape, Aditya A.; Chung, Soon-Jo; et el." }, { "id": "https://authors.library.caltech.edu/records/w8pww-yh795", "eprint_id": 73162, "eprint_status": "archive", "datestamp": "2023-08-19 07:38:44", "lastmod": "2023-10-24 15:05:19", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Paranjape-A-A", "name": { "family": "Paranjape", "given": "Aditya" }, "orcid": "0000-0002-3164-3215" }, { "id": "Kim-Joseph", "name": { "family": "Kim", "given": "Joseph" } }, { "id": "Gandhi-Nihar", "name": { "family": "Gandhi", "given": "Nihar" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Experimental Demonstration of Perching by an Articulated Wing MAV", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2011 by Aditya A. Paranjape, Joseph Kim, Nihar Gandhi and Soon-Jo Chung. Published by the American Institute of Aeronautics and Astronautics, Inc.\n\nThis project was supported by the Air Force Office of Scientific Research (AFOSR) under the Young Investigator Award Program (Grant No. FA95500910089) monitored by Dr. W. Larkin. The original problem was posed by Dr. Gregg Abate (AFRL). This paper also benefitted from stimulating discussions with Mr. Johnny Evers (AFRL) and Dr. Animesh Chakravarthy. The authors thank undergraduate research assistants Dan Chuchawat, Li Pan, Michael Looby, and Daniel Park for their contributions to the experiments, and Prof.\nJames Phillips (MechSE UIUC) and Mr. Greg Milner (AE UIUC) for allowing us to schedule experiments quite liberally in an otherwise busy materials testing facility.\n\nPublished - perchGNC2011.pdf
", "abstract": "This paper presents an experimental demonstration of perching by a micro aerial vehicle (MAV) equipped with articulated wings. A novel feature of the MAV considered in\nthis paper is that wing dihedral, controlled independently on both wings, is used for yaw stability and control as well as for maintaining the flight path angle. Yaw stability and control are essential for perching in tightly constrained places. The experiments described in this paper were conducted indoors and flight parameters are measured using the VICON motion capture system.", "date": "2011-08", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2011-6403", "id_number": "CaltechAUTHORS:20161222-132209268", "isbn": "978-1-60086-952-5", "book_title": "AIAA Guidance, Navigation, and Control Conference 2011", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161222-132209268", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA95500910089" } ] }, "other_numbering_system": { "items": [ { "id": "2011-6403", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2011-6403", "primary_object": { "basename": "perchGNC2011.pdf", "url": "https://authors.library.caltech.edu/records/w8pww-yh795/files/perchGNC2011.pdf" }, "pub_year": "2011", "author_list": "Paranjape, Aditya; Kim, Joseph; et el." }, { "id": "https://authors.library.caltech.edu/records/fg4mg-3px53", "eprint_id": 73154, "eprint_status": "archive", "datestamp": "2023-08-19 07:38:34", "lastmod": "2023-10-24 15:04:56", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Morgan-Daniel", "name": { "family": "Morgan", "given": "Daniel" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Blackmore-L", "name": { "family": "Blackmore", "given": "Lars" } }, { "id": "Acikmese-B", "name": { "family": "Acikmese", "given": "Behcet" } }, { "id": "Bayard-D-S", "name": { "family": "Bayard", "given": "David S." } }, { "id": "Hadaegh-F-Y", "name": { "family": "Hadaegh", "given": "Fred Y." } } ] }, "title": "Swarm Keeping Strategies for Spacecraft under J_2 and Atmospheric Drag Perturbations", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2011 American Institute of Aeronautics and Astronautics. \n\nThe research was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. \n\nAdditionally, this research was carried out in part under the NASA Space Technology Research Fellowship, NASA Grant #NNX11AM84H. Government sponsorship acknowledged. Additional thanks to Insu Chang, Austin Nicholas, Milan Mandic, and Marco Quadrelli for constructive comments.\n\nPublished - MorganSwarmKeeping.pdf
", "abstract": "This paper presents several new open-loop guidance methods for spacecraft swarms composed of hundreds to thousands of agents with each spacecraft having modest capabilities. These methods have three main goals: preventing relative drift of the swarm, preventing collisions within the swarm, and minimizing the propellant used throughout the mission. The development of these methods progresses by eliminating drift using the Hill-Clohessy-Wiltshire equations, removing drift due to nonlinearity, and minimizing the J_2 drift. In order to verify these guidance methods, a new dynamic model for the relative motion of spacecraft is developed. These dynamics include the two main disturbances for spacecraft in Low Earth Orbit (LEO), J_2 and atmospheric drag. Using this dynamic model, numerical simulations are provided at each step to show the effectiveness of each method and to see where improvements can be made. The main result is a set of initial conditions for each spacecraft in the swarm which provides the trajectories for hundreds of collision-free orbits in the presence of J_2. Finally, a multi-burn strategy is developed in order to provide hundreds of collision-free orbits under the influence of atmospheric drag. This last method works by enforcing the initial conditions multiple times throughout the mission thereby providing collision-free trajectories for the duration of the mission.", "date": "2011-08", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics (AIAA)", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2011-6632", "id_number": "CaltechAUTHORS:20161222-113047812", "isbn": "978-1-60086-952-5", "book_title": "AIAA Guidance, Navigation, and Control Conference 2011", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161222-113047812", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" }, { "agency": "NASA" }, { "agency": "NASA", "grant_number": "NNX11AM84H" } ] }, "other_numbering_system": { "items": [ { "id": "2011-6632", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2011-6632", "primary_object": { "basename": "MorganSwarmKeeping.pdf", "url": "https://authors.library.caltech.edu/records/fg4mg-3px53/files/MorganSwarmKeeping.pdf" }, "pub_year": "2011", "author_list": "Morgan, Daniel; Chung, Soon-Jo; et el." }, { "id": "https://authors.library.caltech.edu/records/yhp1a-bzy61", "eprint_id": 72428, "eprint_status": "archive", "datestamp": "2023-08-19 07:38:29", "lastmod": "2023-10-23 22:33:36", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Chang-Insu", "name": { "family": "Chang", "given": "Insu" } }, { "id": "Hadaegh-F-Y", "name": { "family": "Hadaegh", "given": "Fred Y." } } ] }, "title": "Phase Synchronization Control of Robotic Networks on Periodic Ellipses with Adaptive Network Topologies", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2011 California Institute of Technology. \n\nThe research was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. Government sponsorship acknowledged. The authors gratefully acknowledge Lars Blackmore and Daniel Morgan for constructive comments.\n\nPublished - AIAA-2011-6631-730.pdf
", "abstract": "This paper presents a novel formation control method for a large number of robots or vehicles described by Euler-Lagrange (EL) systems moving in elliptical orbits. A new\ncoordinate transformation method for phase synchronization of networked EL systems in elliptical trajectories is introduced to define desired formation patterns. The proposed phase synchronization controller synchronizes the motions of agents, thereby yielding a smaller synchronization error than an uncoupled control law in the presence of bounded disturbances. A complex time-varying and switching network topology, constructed by the\nadaptive graph Laplacian matrix, relaxes the standard requirement of consensus stability, even permitting stabilization on an arbitrary unbalanced graph. The proofs of stability are constructed by robust contraction analysis, a relatively new nonlinear stability tool. An\nexample of reconfiguring swarms of spacecraft in Low Earth Orbit shows the effectiveness of the proposed phase synchronization controller for a large number of complex EL systems moving in elliptical orbits.", "date": "2011-08", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics (AIAA)", "place_of_pub": "Reston, VA", "pagerange": "1-19", "id_number": "CaltechAUTHORS:20161130-081544822", "isbn": "978-1-60086-952-5", "book_title": "AIAA Guidance, Navigation, and Control Conference 2011", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161130-081544822", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2011-6631", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2011-6631", "primary_object": { "basename": "AIAA-2011-6631-730.pdf", "url": "https://authors.library.caltech.edu/records/yhp1a-bzy61/files/AIAA-2011-6631-730.pdf" }, "pub_year": "2011", "author_list": "Chung, Soon-Jo; Chang, Insu; et el." }, { "id": "https://authors.library.caltech.edu/records/tfpz8-56031", "eprint_id": 98935, "eprint_status": "archive", "datestamp": "2023-08-19 07:14:28", "lastmod": "2023-10-18 17:44:38", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Rabinovitch-J", "name": { "family": "Rabinovitch", "given": "Jason" }, "orcid": "0000-0002-1914-7964" }, { "id": "Brion-V", "name": { "family": "Brion", "given": "Vincent" } }, { "id": "Blanquart-G", "name": { "family": "Blanquart", "given": "Guillaume" }, "orcid": "0000-0002-5074-9728" } ] }, "title": "Effect of a Splitter Plate on the Dynamics of a Vortex Pair", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2011 by Jason Rabinovitch. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.\n\nJ. Rabinovitch would like to thank the Dual Masters Program between the California Institute of Technology and\nEcole Polytechnique, and the Partner University Fund for funding him while performing the experimental\ncomponent of this research. Also thank you to the members of ONERA DAFE, Meudon, for all of their help with\nthe experiments and the post-treatment of the experimental data.\n\nPublished - AIAA-2011-3894-368.pdf
", "abstract": "An experimental and numerical study was performed to investigate the behavior of a counter-rotating vortex pair as well as a single vortex in the vicinity of a wall. A wind tunnel with two NACA0012 profiles mounted vertically with an optional splitter plate in the center and a 3D PIV system were used to experimentally study the interactions between two counter-rotating vortices, as well as the interactions between a vortex and a wall. Many fundamental differences were found between the two configurations, which promote the growth of the Crow instability in the two vortex configuration, but not in the one vortex/wall configuration. The numerical results obtained re-enforced the experimental results, and emphasize the fundamental physical differences between the two configurations. While modeling a vortex wall system with an image vortex may give correct integral results for loads experienced by blades, this model does not accurately describe the downstream dynamics of the vortex system.", "date": "2011-06-27", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2011-3894", "id_number": "CaltechAUTHORS:20190930-110458199", "isbn": "9781600869471", "book_title": "41st AIAA Fluid Dynamics Conference and Exhibit", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190930-110458199", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech" }, { "agency": "\u00c9cole Polytechnique" }, { "agency": "Partner University Fund" } ] }, "other_numbering_system": { "items": [ { "id": "2011-3894", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2011-3894", "primary_object": { "basename": "AIAA-2011-3894-368.pdf", "url": "https://authors.library.caltech.edu/records/tfpz8-56031/files/AIAA-2011-3894-368.pdf" }, "pub_year": "2011", "author_list": "Rabinovitch, Jason; Brion, Vincent; et el." }, { "id": "https://authors.library.caltech.edu/records/0r65h-mm992", "eprint_id": 103443, "eprint_status": "archive", "datestamp": "2023-08-22 02:44:52", "lastmod": "2024-01-15 04:30:54", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kidane-A", "name": { "family": "Kidane", "given": "Addis" } }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "Guruswami" }, "orcid": "0000-0002-2912-0001" } ] }, "title": "Failure and Fracture Behavior of Brittle Polymer Foam", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Strain Field; Digital Image Correlation; Foam Material; Polymer Foam; Intact Specimen", "note": "\u00a9 2011 Springer Science+Businees Media, LLC. \n\nFirst Online: 18 May 2011. \n\nThis work was supported by the Office of Naval Research (Dr. Y. D. S Rajapakse, Program Manager) and is gratefully acknowledged.", "abstract": "Experimental study was performed to investigate the fracture behavior of relatively brittle polymer foam. A single notch bending specimen made of a PVC core cell foam A-series, A 800 and A 1200, are used for the investigation. To measure the strain around the defect section, a 2D digital image correction (DIC) technique was used. The fracture initiation toughness was calculated from the load displacement curve and a strain fields obtained from DIC technique. Furthermore a study was performed to investigate the failure behavior of foam core with sharp cracks, notch and circular hole. To reduce the size effect, the net cross-sectional areas of the specimen for all the geometries considered are kept constant. An Instron tensile loading machine was used and the tensile load was measured directly through the load cell. The full strain field around the section was measured using DIC and the data points at the interest location were extracted. The result was compared with the dog-bone tensile experiment of intact specimen. It was observed that, the net section strength for specimen with cracks, notch and circular hole is higher than that of the intact foam core.", "date": "2011-05-18", "date_type": "published", "publisher": "Springer", "place_of_pub": "New York, NY", "pagerange": "91-98", "id_number": "CaltechAUTHORS:20200526-093121161", "isbn": "978-1-4614-0221-3", "book_title": "Experimental and Applied Mechanics", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200526-093121161", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Proulx-T", "name": { "family": "Proulx", "given": "Tom" } } ] }, "doi": "10.1007/978-1-4614-0222-0_13", "pub_year": "2011", "author_list": "Kidane, Addis and Ravichandran, Guruswami" }, { "id": "https://authors.library.caltech.edu/records/nt0d1-wam47", "eprint_id": 103367, "eprint_status": "archive", "datestamp": "2023-08-22 02:44:40", "lastmod": "2024-01-15 04:30:47", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Alkhader-M", "name": { "family": "Alkhader", "given": "Maen" } }, { "id": "Knauss-W-G", "name": { "family": "Knauss", "given": "Wolfgang" } }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "Guruswami" }, "orcid": "0000-0002-2912-0001" } ] }, "title": "Experimental arrangement for measuring the high-strain-rate response of polymers under pressures", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Constitutive Model; Inclination Angle; High Strain Rate; Shear Strain Rate; Shear Response", "note": "\u00a9 2011 The Society for Experimental Mechanics, Inc. \n\nFirst Online: 17 May 2011.", "abstract": "This study aims to investigate the high-strain-rate shear response of viscoelastic elastomeric coatings at large strains and under elevated levels of hydrostatic pressure. Results of this study shed light on the combined effects of deformation rate and pressure which might promote a transition from viscoelastic to glassy behavior. This work utilizes a Split Hopkinson Pressure Bar (SHPB) apparatus in conjunction with a customized version of the recently proposed Shear Compression Specimen (SCS) which consists of a polymer gage section with two metal ends that remain essentially rigid during deformation. Detailed finite element simulations were used to customize the adopted specimen, to determine its proper dimensions and promote its functionality. The customized specimen permits subjecting the tested specimen to a state of uniform pressure and shear stress, while allowing for measuring pressure, shear stress and shear strain directly. Results obtained using the customized specimen, which are included in this paper, illustrate its usefulness in measuring the effect of high-strain-rate, large strain and hydrostatic pressure on the shear stress-strain response of viscoelastic elastomers.", "date": "2011-05-11", "date_type": "published", "publisher": "Springer", "place_of_pub": "New York, NY", "pagerange": "139-144", "id_number": "CaltechAUTHORS:20200520-144612061", "isbn": "978-1-4614-0212-1", "book_title": "Mechanics of Time-Dependent Materials and Processes in Conventional and Multifunctional Materials", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200520-144612061", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Proulx-T", "name": { "family": "Proulx", "given": "Tom" } } ] }, "doi": "10.1007/978-1-4614-0213-8_20", "pub_year": "2011", "author_list": "Alkhader, Maen; Knauss, Wolfgang; et el." }, { "id": "https://authors.library.caltech.edu/records/nwypj-d4f23", "eprint_id": 29969, "eprint_status": "archive", "datestamp": "2023-08-19 06:23:43", "lastmod": "2023-10-24 22:37:59", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "McLeod-E", "name": { "family": "McLeod", "given": "Euan" } }, { "id": "Troian-S-M", "name": { "family": "Troian", "given": "Sandra M." }, "orcid": "0000-0003-1224-6377" } ] }, "title": "One step non-contact fabrication of polymer microlens arrays by thermocapillary lithography", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2009 Optical Society of America.\nDate of Current Version: 14 July 2011.\n\nPublished - ISI000295612401146Proceedings.pdf
", "abstract": "Thermocapillary lithography, a continuous-relief patterning technique, is used to fabricate polymer microlens arrays with variable pitch and focal length. Pattern definition results from sculpting by thermocapillary forces imposed by a cooled mask.", "date": "2011-05", "date_type": "published", "publisher": "Optical Society of America", "place_of_pub": "Washington, DC", "pagerange": "CML3", "id_number": "CaltechAUTHORS:20120404-084148237", "isbn": "978-1-4577-1223-4", "book_title": "2011 Conference on Lasers and Electro-Optics (CLEO)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120404-084148237", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "12119546", "name": "INSPEC Accession Number" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "primary_object": { "basename": "ISI000295612401146Proceedings.pdf", "url": "https://authors.library.caltech.edu/records/nwypj-d4f23/files/ISI000295612401146Proceedings.pdf" }, "pub_year": "2011", "author_list": "McLeod, Euan and Troian, Sandra M." }, { "id": "https://authors.library.caltech.edu/records/qqbmb-j8z50", "eprint_id": 72489, "eprint_status": "archive", "datestamp": "2023-08-19 06:25:27", "lastmod": "2023-10-23 15:10:56", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chang-Insu", "name": { "family": "Chang", "given": "Insu" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Hadaegh-F-Y", "name": { "family": "Hadaegh", "given": "Fred Y." } } ] }, "title": "Novel Coordinate Transformation and Robust Cooperative Formation Control for Swarms of Spacecraft", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2011 California Institute of Technology. \n\nThe research was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. Government sponsorship acknowledged. The first author was supported by the University of Illinois at Urbana-Champaign. The authors gratefully acknowledge Dr. Lars Blackmore and Dr. Behcet Acikmese at JPL/NASA and Daniel Morgan at UIUC for their constructive discussion.\n\nPublished - chang2011SFFMT.pdf
", "abstract": "This paper presents a new coordinate transformation method for controlling a large number of spacecraft moving in elliptical orbits. A new coordinate transformation\nmethod for phase synchronization of spacecraft in relative elliptical orbits is introduced to effectively maintain desired formation patterns. The proposed controller, which\nemploys both the adaptive graph Laplacian matrix and the distance-based connectivity rule, synchronizes the relative motions of spacecraft with a guaranteed property of\nrobustness. A complex time-varying network topology, constructed by the proposed controller, relaxes the standard requirement of consensus stability, even permitting\nstabilization on an arbitrary unbalanced graph. A challenging example of reconfiguring swarms of spacecraft shows the reliability of the coordinate transformation method and the effectiveness of the proposed phase synchronization controller.", "date": "2011-05", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20161201-072209482", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161201-072209482", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" }, { "agency": "University of Illinois Urbana-Champaign" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "primary_object": { "basename": "chang2011SFFMT.pdf", "url": "https://authors.library.caltech.edu/records/qqbmb-j8z50/files/chang2011SFFMT.pdf" }, "pub_year": "2011", "author_list": "Chang, Insu; Chung, Soon-Jo; et el." }, { "id": "https://authors.library.caltech.edu/records/mttpk-ken14", "eprint_id": 103623, "eprint_status": "archive", "datestamp": "2023-08-22 02:32:27", "lastmod": "2024-01-15 04:31:07", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Alkhader-M", "name": { "family": "Alkhader", "given": "Maen" } }, { "id": "Knauss-W-G", "name": { "family": "Knauss", "given": "W. G." } }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "G." }, "orcid": "0000-0002-2912-0001" } ] }, "title": "The influence of pressure on the large deformation shear response of a Polyurea", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Shear Stiffness; Prony Series; Shear Response; Free Volume Theory; Cylindrical Disk", "note": "\u00a9 2010 Society for Experimental Mechanics Inc. \n\nFirst Online: 15 April 2011. \n\nThe authors wish to thank Dr. Roshdy Barsoum of the Office of Naval Research through his guidance and cooperation and for the sustained support of this difficult effort under Grant ONR N000 14-09-1-0552.", "abstract": "A new shear-compression experiment is developed to characterize the influence of hydrostatic pressure on the shear constitutive response of nearly incompressible viscoelastic materials undergoing large deformations. In this design, a uniform torsional shear stress is superposed on a uniform hydrostatic compressive state of stress generated by axially deforming samples confined by a stack of thin steel disks. The new design is effective in applying uniform multiaxial compressive strain while preventing buckling and barreling during inelastic deformation. In addition, it allows for the direct measurement of the stress and strain fields during the deformation history. The new shear-compression setup is developed to aid in characterizing the influence of pressure or negative dilatation on the shear constitutive response of viscoelastic materials in general and Polyurea in particular. Experimental results obtained with this technique illustrate the significant increase in the shear stiffness of polyurea under moderate to high hydrostatic pressures.", "date": "2011-04-15", "date_type": "published", "publisher": "Springer", "place_of_pub": "New York, NY", "pagerange": "287-295", "id_number": "CaltechAUTHORS:20200601-143119734", "isbn": "978-1-4419-9498-1", "book_title": "Time Dependent Constitutive Behavior and Fracture/Failure Processes", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200601-143119734", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "N000 14-09-1-0552" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Proulx-T", "name": { "family": "Proulx", "given": "Tom" } } ] }, "doi": "10.1007/978-1-4419-9794-4_40", "pub_year": "2011", "author_list": "Alkhader, Maen; Knauss, W. G.; et el." }, { "id": "https://authors.library.caltech.edu/records/sahgt-6qd66", "eprint_id": 98940, "eprint_status": "archive", "datestamp": "2023-08-19 06:10:12", "lastmod": "2023-10-18 17:44:49", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Mallikarachchi-H-M-Y-C", "name": { "family": "Mallikarachchi", "given": "H. M. Y. C." } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "S." }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Design and Validation of Thin-Walled Composite Deployable Booms with Tape-Spring Hinges", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2011 by H. M. Y. C. Mallikarachchi and S. Pellegrino. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission. \n\nWe thank Dr Michael Sutcliffe for helpful discussions and Professor Chiara Daraio and Dr Jinkyu Yang for help with high speed imaging. John Ellis (Hexcel, UK) kindly provided materials for our experiments. HM thanks the Cambridge Commonwealth Trust and the California Institute of Technology for financial support.\n\nAccepted Version - MallikarachchiAIAA2011.pdf
", "abstract": "This paper presents a 1 m long self-deployable boom that could be folded around a spacecraft. Previously developed simulation techniques are used to analyze this two-hinge boom, made from two-ply plain weave carbon fiber laminate. A stress-resultant based failure criterion is used to study safety of the structure during both stowage and dynamic deployment. A safe design that latches without any overshoot is selected and validated by a dynamic deployment experiment.", "date": "2011-04-04", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2011-2019", "id_number": "CaltechAUTHORS:20190930-110458726", "isbn": "9781600869518", "book_title": "52nd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190930-110458726", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Cambridge Commonwealth Trust" }, { "agency": "Caltech" } ] }, "other_numbering_system": { "items": [ { "id": "2011-2019", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2011-2019", "primary_object": { "basename": "MallikarachchiAIAA2011.pdf", "url": "https://authors.library.caltech.edu/records/sahgt-6qd66/files/MallikarachchiAIAA2011.pdf" }, "pub_year": "2011", "author_list": "Mallikarachchi, H. M. Y. C. and Pellegrino, S." }, { "id": "https://authors.library.caltech.edu/records/qdmk2-8w128", "eprint_id": 98941, "eprint_status": "archive", "datestamp": "2023-08-19 06:10:17", "lastmod": "2023-10-18 17:44:51", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kwok-Kawai", "name": { "family": "Kwok", "given": "Kawai" }, "orcid": "0000-0001-6876-4267" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Viscoelastic effects in tape-springs", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2011 by K. Kwok and S. Pellegrino. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission. \n\nThe authors are grateful to Professor Wolfgang Knauss for helpful comments and discussions. Financial support for KK by the Croucher Foundation is acknowledged.\n\nAccepted Version - KwokAIAA2011.pdf
", "abstract": "Following recent interest in constructing large self-deployable structures made of reinforced polymer materials, this paper presents a detailed study of viscoelastic effects in folding, stowage, and deployment of tape-springs which often act as deployment actuators in space structures. Folding and stowage behavior at different temperatures and rates are studied. It is found that the peak load increases with the folding rate but reduces with temperature. It is also shown that a load reduction of as much as 60% is possible during stowage due to relaxation behavior. Deployment behavior after significant load relaxation demonstrates features distinct from elastic tape-springs. It starts with a short dynamic response, followed by a quasi-static deployment, and ends with a slow creep recovery process. A key feature is that the localized fold stays stationary throughout deployment. Finite element simulations that incorporate an experimentally characterized viscoelastic material model are presented and found to capture the folding and stowage behavior accurately. The general features of deployment response are also predicted, but with larger discrepancy.", "date": "2011-04-04", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2011-2022", "id_number": "CaltechAUTHORS:20190930-110458819", "isbn": "9781600869518", "book_title": "52nd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190930-110458819", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Croucher Foundation" } ] }, "other_numbering_system": { "items": [ { "id": "2011-2022", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2011-2022", "primary_object": { "basename": "KwokAIAA2011.pdf", "url": "https://authors.library.caltech.edu/records/qdmk2-8w128/files/KwokAIAA2011.pdf" }, "pub_year": "2011", "author_list": "Kwok, Kawai and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/tpkpq-szv03", "eprint_id": 98931, "eprint_status": "archive", "datestamp": "2023-08-19 06:10:07", "lastmod": "2023-10-18 17:44:27", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Patterson-K", "name": { "family": "Patterson", "given": "Keith" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Shape Correction of Thin Mirrors", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2011 by Keith Patterson and Sergio Pellegrino. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission. \n\nWe thank Jim Breckinridge for helpful discussions of telescope design and Chiara Daraio, Eleftherios Gdoutos, and Andrew Shapiro for help and advice regarding the fabrication of a prototype. Financial support from the Keck Institute of Space Studies at Caltech is gratefully acknowledged.\n\nAccepted Version - Shape_correction_of_thin_mirrors_2011.pdf
", "abstract": "Future large space observatories will require large apertures to provide better resolution and greater light gathering power; thin mirror technologies provide one possible route for addressing this need. This paper presents a study of a 10 m diameter sparse aperture based on a collection of thin, active mirror segments with identical initial shapes. A preliminary design for a 1 m diameter mirror segment is proposed and an investigation into the performance of this design is carried out utilizing finite element modeling tools. The results indicate that it is possible to adapt the generic segment shapes to fit the local mirror shape, and achieve near diffraction-limited performance through the use of lightweight, surface-parallel actuators. These actuators may also be used for thermal compensation. Additionally, a design for a scaled 10 cm diameter prototype mirror to test and validate the envisioned scheme is presented.", "date": "2011-04-04", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2011-1827", "id_number": "CaltechAUTHORS:20190930-110457762", "isbn": "9781600869518", "book_title": "52nd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190930-110457762", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Keck Institute for Space Studies (KISS)" } ] }, "other_numbering_system": { "items": [ { "id": "2011-1827", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Keck-Institute-for-Space-Studies" } ] }, "doi": "10.2514/6.2011-1827", "primary_object": { "basename": "Shape_correction_of_thin_mirrors_2011.pdf", "url": "https://authors.library.caltech.edu/records/tpkpq-szv03/files/Shape_correction_of_thin_mirrors_2011.pdf" }, "pub_year": "2011", "author_list": "Patterson, Keith and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/p1qec-p2a92", "eprint_id": 98942, "eprint_status": "archive", "datestamp": "2023-08-19 06:10:21", "lastmod": "2023-10-18 17:44:54", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Stohlman-O-R", "name": { "family": "Stohlman", "given": "O. R." } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "S." }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Effects of Component Properties on the Accuracy of a Joint-Dominated Deployable Mast", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2011 by Sergio Pellegrino and Olive Stohlman. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.\n\nAccepted Version - StohlmanAIAA2011.pdf
", "abstract": "Jointed-dominated deployable masts are used in space applications, including telescopes, where there is a demand for a long, slender structure that can be packed into a conven-tional launch shroud. Depending on the application, there may be stringent demands on the stiffness and shape accuracy of the mast. This paper presents a parametric study of the significance of a number of mast part properties for a precision deployable mast's perfor-mance under quasi-static shear load. The mast's cable preload, latching system behavior, and joint friction are explored as candidates for parts requiring detailed characterization for accurate mast performance prediction.", "date": "2011-04-04", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2011-2163", "id_number": "CaltechAUTHORS:20190930-110458917", "isbn": "9781600869518", "book_title": "52nd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190930-110458917", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2011-2163", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2011-2163", "primary_object": { "basename": "StohlmanAIAA2011.pdf", "url": "https://authors.library.caltech.edu/records/p1qec-p2a92/files/StohlmanAIAA2011.pdf" }, "pub_year": "2011", "author_list": "Stohlman, O. R. and Pellegrino, S." }, { "id": "https://authors.library.caltech.edu/records/7yc73-5c258", "eprint_id": 73098, "eprint_status": "archive", "datestamp": "2023-08-19 05:46:45", "lastmod": "2023-10-24 15:02:11", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Fong-Daniel", "name": { "family": "Fong", "given": "Daniel" } }, { "id": "Dorothy-M-R", "name": { "family": "Dorothy", "given": "Michael" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "RoboBat: Dynamics and Control of a Robotic Bat Flapping Flying Testbed", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2011 American Institute of Aeronautics and Astronautics. \n\nThis project was supported by the Air Force Office of Scientific Research (AFOSR) under the Young Investigator Award Program (Grant No. FA95500910089) monitored by Dr. W. Larkin. The authors would like to thank the following students from the University of Illinois at Urbana-Champaign: Jonathan Yong, James Holtman, Andrew Meister, and Matthew Schipp.\n\nPublished - infotech2011_bat.pdf
", "abstract": "This paper investigates the control of the phase difference in between three different motions of bat flight: pitching, mapping, and lead-lag. For active control, a robotic bat test bed capable of simulating different wing motions is used to test the control of these wing motions and the phase differences using central pattern generators (CPG's). Previous work with the robotic bat is expanded upon by modifying the robotic bat test bed to allow for three dimensional motions of the entire bat, instead of only the wings. This is done by mounting the robotic bat onto a 3D pendulum. Experiments analyzing the steady state behavior of the bat's flight with varying phase differences showed a change of pitch while elevation and forward velocity remains constant. This shows promising results regarding the relation between phase differences of wing motions and longitudinal stability.", "date": "2011-03", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics (AIAA)", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2011-1435", "id_number": "CaltechAUTHORS:20161221-134632205", "isbn": "978-1-60086-944-0", "book_title": "Infotech@Aerospace 2011", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161221-134632205", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA95500910089" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2011-1435", "primary_object": { "basename": "infotech2011_bat.pdf", "url": "https://authors.library.caltech.edu/records/7yc73-5c258/files/infotech2011_bat.pdf" }, "pub_year": "2011", "author_list": "Fong, Daniel; Dorothy, Michael; et el." }, { "id": "https://authors.library.caltech.edu/records/k3yfh-rd485", "eprint_id": 72454, "eprint_status": "archive", "datestamp": "2023-08-19 05:46:40", "lastmod": "2023-10-23 22:35:41", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Yang-Junho", "name": { "family": "Yang", "given": "Junho" } }, { "id": "Rao-Dushyant", "name": { "family": "Rao", "given": "Dushyant" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Hutchinson-Seth", "name": { "family": "Hutchinson", "given": "Seth" }, "orcid": "0000-0002-3949-6061" } ] }, "title": "Monocular Vision based Navigation in GPS-Denied Riverine Environments", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2011 American Institute of Aeronautics and Astronautics. \n\nThis project was supported by the Office of Naval Research (ONR). The authors are also grateful to Jonathan Yong and Koray Celik for their support.\n\nPublished - c8faa4ec88383c08587e4c4746dd21388b26.pdf
", "abstract": "This paper presents a new method to estimate the range and bearing of landmarks and solve the simultaneous localization and mapping (SLAM) problem. The proposed\nranging and SLAM algorithms have application to a micro aerial vehicle (MAV) flying through riverine environments which occasionally involve heavy foliage and forest canopy.\nMonocular vision navigation has merits in MAV applications since it is lightweight and provides abundant visual cues of the environment in comparison to other ranging methods.\nIn this paper, we suggest a monocular vision strategy incorporating image segmentation and epipolar geometry to extend the capability of the ranging method to unknown outdoor environments. The validity of our proposed method is verified through experiments in a river-like environment.", "date": "2011-03", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics (AIAA)", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2011-1403", "id_number": "CaltechAUTHORS:20161130-135343959", "isbn": "978-1-60086-944-0", "book_title": "Infotech@Aerospace Conference and Exhibit 2011", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161130-135343959", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)" } ] }, "other_numbering_system": { "items": [ { "id": "2011-1403", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2011-1403", "primary_object": { "basename": "c8faa4ec88383c08587e4c4746dd21388b26.pdf", "url": "https://authors.library.caltech.edu/records/k3yfh-rd485/files/c8faa4ec88383c08587e4c4746dd21388b26.pdf" }, "pub_year": "2011", "author_list": "Yang, Junho; Rao, Dushyant; et el." }, { "id": "https://authors.library.caltech.edu/records/964yk-nds48", "eprint_id": 103427, "eprint_status": "archive", "datestamp": "2023-08-22 01:52:42", "lastmod": "2024-01-15 04:30:52", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Brown-J-L", "name": { "family": "Brown", "given": "J. L." } }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "G." }, "orcid": "0000-0002-2912-0001" } ] }, "title": "High Pressure Hugoniot Measurements Using Converging Shocks", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Shock Wave; Impact Velocity; Outer Cylinder; Mach Disk; Mach Reflection", "note": "\u00a9 2011 The Society for Experimental Mechanics, Inc. \n\nFirst Online: 25 January 2011. \n\nThe research support provided by the Caltech Center for the Predictive Modeling and Simulation of High-Energy Density Dynamic Response of Materials through the U.S. Department of Energy contract DE-FC52-08NA28613 is gratefully acknowledged.", "abstract": "Plate impact experiments are a powerful tool in equation of state development, but are inherently limited by the range of impact velocities accessible to the gun. In an effort to dramatically increase the range of pressures which can be studied with available impact velocities, a new experimental technique is being developed. The possibility of using converging shock waves to produce a high pressure Mach reflection is examined. The technique proposed uses a composite target simply consisting of two concentric cylinders, with the only requirement being the initial shock speed in the outer cylinder is greater than that in the inner cylinder. Conically converging shocks will be generated at the interface due to the impedance mismatch and axisymmetric geometry of the composite target. Upon convergence, an irregular reflection must occur, at which point the conical analog of a Mach reflection develops. Once the Mach reflection reaches a steady state, the high pressure state in the Mach disk can be measured using velocity interferometry and impedance matching techniques. Experimental results on a copper inner cylinder are in good agreement with numerical simulations and data in the literature.", "date": "2011-01-25", "date_type": "published", "publisher": "Springer", "place_of_pub": "New York, NY", "pagerange": "403-409", "id_number": "CaltechAUTHORS:20200522-140337858", "isbn": "978-1-4419-8227-8", "book_title": "Dynamic Behavior of Materials", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200522-140337858", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Department of Energy (DOE)", "grant_number": "DE-FC52-08NA28613" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Proulx-T", "name": { "family": "Proulx", "given": "Tom" } } ] }, "doi": "10.1007/978-1-4419-8228-5_59", "pub_year": "2011", "author_list": "Brown, J. L. and Ravichandran, G." }, { "id": "https://authors.library.caltech.edu/records/69vcc-ygz09", "eprint_id": 103424, "eprint_status": "archive", "datestamp": "2023-08-22 01:52:34", "lastmod": "2024-01-15 04:30:48", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lamberson-L-E", "name": { "family": "Lamberson", "given": "Leslie E." } }, { "id": "Rosakis-A-J", "name": { "family": "Rosakis", "given": "Ares J." }, "orcid": "0000-0003-0559-0794" }, { "id": "Eliasson-V", "name": { "family": "Eliasson", "given": "Veronica" } } ] }, "title": "In-situ Optical Investigations of Hypervelocity Impact Induced Dynamic Fracture", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Rarefaction Wave; International Space Station; Dynamic Stress Intensity Factor; Space Debris; Crack Speed", "note": "\u00a9 2011 The Society for Experimental Mechanics, Inc. \n\nFirst Online: 25 January 2011. \n\nThe authors acknowledge support from the Department of Energy Award DE-PS52-07NA28208 through the National Nuclear Security Administration, National Science Foundation Graduate Research Fellowship, as well as the NASA Aeronautics Scholarship Program through the American Society of Engineering Education.", "abstract": "Two independent optical methods are used to analyze the dynamic material behavior of Mylar and Homalite-100 subjected to hypervelocity impact. Birefringent targets are loaded in tension inside a two-stage light-gas gun vacuum chamber, and are impacted with a 5 mg nylon slug at velocities between 3 and 6 km/s. Caustics and photoelasticity combined with high-speed photography are used to determine dynamic stress intensity behavior around the crack tip during and after impact. Homalite-100 lower crack tip speeds are subjected to reflecting boundary shear waves from the nylon impact, and thereby the crack path exhibits distinct kinks; whereas Mylar higher crack tip speeds provides distinguishable isochromatic patterns and an unadulterated fracture surface. Shear wave patterns in the target from photoelastic effects are compared to results from numerical simulations using the Overture Suite, which solves linear elasticity equations on overlapping curvilinear grids by means of adaptive mesh refinement.", "date": "2011-01-25", "date_type": "published", "publisher": "Springer", "place_of_pub": "New York, NY", "pagerange": "31-37", "id_number": "CaltechAUTHORS:20200522-132645095", "isbn": "978-1-4419-8227-8", "book_title": "Dynamic Behavior of Materials", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200522-132645095", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Department of Energy (DOE)", "grant_number": "DE-PS52-07NA28208" }, { "agency": "NSF Graduate Research Fellowship" }, { "agency": "NASA" }, { "agency": "American Society of Engineering Education" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Proulx-T", "name": { "family": "Proulx", "given": "Tom" } } ] }, "doi": "10.1007/978-1-4419-8228-5_6", "pub_year": "2011", "author_list": "Lamberson, Leslie E.; Rosakis, Ares J.; et el." }, { "id": "https://authors.library.caltech.edu/records/qk9pn-wrz13", "eprint_id": 98945, "eprint_status": "archive", "datestamp": "2023-08-19 05:13:42", "lastmod": "2023-10-18 17:45:01", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Gharib-M", "name": { "family": "Gharib", "given": "Morteza" }, "orcid": "0000-0003-0754-4193" }, { "id": "Kim-Daegyoum", "name": { "family": "Kim", "given": "Daegyoum" } }, { "id": "Khodadoust-A", "name": { "family": "Khodadoust", "given": "Abdollah" } } ] }, "title": "Progress Towards the Development of a 3D PIV Flow Measurement System for Wind Tunnel Applications", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2011 American Institute of Aeronautics and Astronautics.", "abstract": "Current instrumentation systems in our nation's wind tunnel facilities are quite inadequate in responding to the demand for better understanding of aerodynamic performance of modern aviation systems. Modern aviation systems rely heavily on the performance of subsystems such as ac winglets, fast response lifting surfaces and micro/macro vortex generators. For example, our current management strategies for the control and alleviation of trailing vortices suffers from the lack of a better understanding of the vortex morphogenesis near wing-tip areas. Flows associated with these system subcomponents are highly three dimensional. To develop a better understanding of these flows, it is important that we develop tools that could provide three dimensional flow fields. In general, current flow mapping methods used in industrial and commercial large wind tunnel facilities are limited to techniques such as multi-point hot wire anemometry, and single point laser Doppler systems. These techniques are handicapped when volumetric data is required for validation of CFD studies. A flow mapping system that could be easily used to obtain volumetric three component velocity data is highly desirable in order to resolve many flow/structure related safety and control issues in modern aviation systems. In this paper we report on progress towards the development of a novel 3D imaging systems that would address abovementioned issues.", "date": "2011-01-04", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2011-1232", "id_number": "CaltechAUTHORS:20190930-110459195", "isbn": "9781600869501", "book_title": "49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190930-110459195", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2011-1232", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2011-1232", "pub_year": "2011", "author_list": "Gharib, Morteza; Kim, Daegyoum; et el." }, { "id": "https://authors.library.caltech.edu/records/766z1-hbw29", "eprint_id": 50093, "eprint_status": "archive", "datestamp": "2023-08-19 05:09:52", "lastmod": "2023-10-17 22:30:30", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Flaherty-W", "name": { "family": "Flaherty", "given": "W." } }, { "id": "Crafton-J", "name": { "family": "Crafton", "given": "J." } }, { "id": "Elliott-G-S", "name": { "family": "Elliott", "given": "G. S." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "J. M." } } ] }, "title": "Application of Fast Pressure Sensitive Paint in Hypervelocity Flow", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2011 by University of Illinois. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.\n\nAIAA 2011-848.\n\nThis work was supported in part by the Air Force Research Laboratory through award FA8650-10-M-3023 with Dr. Daniel Tejtel as Program Manager and in part by the Air Force Office of Scientific Research\nthrough award FA9550-08-1-0172 with Dr. John Schmisseur as Program Manager.\n\nPublished - 385397.pdf
", "abstract": "The development of fast responding pressure sensitive paints for measurements in high-enthalpy, hypersonic flows is reported. Data are obtained for at plate boundary layers in\nan impulse facility with typical test gas times on the order of hundreds of microseconds.\nThe fast pressure sensitive paint is found to have the required response time and sufficient\nsignal level to visualize vortical boundary layer structures in a Mach 5.12 freestream. The\nflow behind protuberance strips with different geometries is evaluated with measurements\nof the vortex frequency and diameter, as well as breakdown distance. Comparisons with\nstatic pressure measurements made using pressure taps show differences of up to a factor\nof three, and calibration sources as well as an alternative lifetime measurement method\nremain to be investigated.", "date": "2011-01", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Red Hook, NY", "id_number": "CaltechAUTHORS:20140929-111458194", "isbn": "978-1-60086-950-1", "book_title": "49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140929-111458194", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Research Laboratory", "grant_number": "FA8650-10-M-3023" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-08-1-0172" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2011-848", "primary_object": { "basename": "385397.pdf", "url": "https://authors.library.caltech.edu/records/766z1-hbw29/files/385397.pdf" }, "pub_year": "2011", "author_list": "Flaherty, W.; Crafton, J.; et el." }, { "id": "https://authors.library.caltech.edu/records/x7ezb-a0s48", "eprint_id": 50100, "eprint_status": "archive", "datestamp": "2023-08-19 05:10:02", "lastmod": "2023-10-17 22:30:53", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Sharma-M", "name": { "family": "Sharma", "given": "M." } }, { "id": "Swantek-A-B", "name": { "family": "Swantek", "given": "A. B." } }, { "id": "Flaherty-W", "name": { "family": "Flaherty", "given": "W." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "J. M." } }, { "id": "Doraiswamy-S", "name": { "family": "Doraiswamy", "given": "S." } }, { "id": "Candler-G-V", "name": { "family": "Candler", "given": "G. V." } } ] }, "title": "Evaluation of Hypervelocity Carbon Dioxide Blunt Body Experiments in an Expansion Tube Facility", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2011 by Manu Sharma. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.\n\nAIAA 2011-136.\n\nFor thermocouple implementation and design advice, the authors would like to thank Professor\nHans Hornung, Drs Simon Sanderson, Jean-Paul Davis, Bahram Valiferdowski, Ivett Leyva, Eric\nMarineau and Adam Rasheed. For co-ordination with CUBRC and expansion tube gas dynamic\ndiscussion, the authors thank Aaron Dufrene for his valuable input.\n\nPublished - 385399.pdf
", "abstract": "This work represents efforts to study high-enthalpy carbon dioxide flows in anticipation\nof the upcoming Mars Science Laboratory (MSL) and future missions. The\ncurrent study extends the previous presentation of experimental results by the comparison\nnow with axisymmetric simulations incorporating detailed thermochemical\nmodeling. The work is motivated by observed anomalies between experimental\nand numerical studies in hypervelocity impulse facilities. In this work, experiments\nare conducted in the Hypervelocity Expansion Tube (HET) which, by virtue of its\nflow acceleration process, exhibits minimal freestream dissociation in comparison\nto reflected shock tunnels. This simplifies the comparison with computational result\nas freestream dissociation and considerable thermochemical excitation can be\nneglected. Shock shapes of the Laboratory aeroshell and spherical geometries are\ncompared with numerical simulations. In an effort to address surface chemistry\nissues arising from high-enthalpy carbon dioxide ground-test based experiments,\nspherical stagnation point and aeroshell heat transfer distributions are also compared\nwith simulation. The shock stand-off distance has been identified in the\npast as sensitive to the thermochemical state and as such, is used here as an experimental\nmeasureable for comparison with CFD and two different theoretical\nmodels. For low-density, small-scale experiments it is seen that models based upon\nassumptions of large binary scaling values are unable to match the experimental\nand numerical results. Very good agreement between experiment and CFD is seen\nfor all shock shapes and heat transfer distributions fall within the non-catalytic and\nsuper-catalytic solutions.", "date": "2011-01", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Red Hook, NY", "id_number": "CaltechAUTHORS:20140929-131815791", "isbn": "978-1-60086-950-1", "book_title": "49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140929-131815791", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2011-136", "primary_object": { "basename": "385399.pdf", "url": "https://authors.library.caltech.edu/records/x7ezb-a0s48/files/385399.pdf" }, "pub_year": "2011", "author_list": "Sharma, M.; Swantek, A. B.; et el." }, { "id": "https://authors.library.caltech.edu/records/y29d6-s9f52", "eprint_id": 50099, "eprint_status": "archive", "datestamp": "2023-08-19 05:09:57", "lastmod": "2023-10-17 22:30:51", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Khokhlov-A-M", "name": { "family": "Khokhlov", "given": "A. M." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "J. M." } }, { "id": "Bacon-C", "name": { "family": "Bacon", "given": "C." } }, { "id": "Aithal-S", "name": { "family": "Aithal", "given": "S." } }, { "id": "Riley-K-M", "name": { "family": "Riley", "given": "K." } } ] }, "title": "Reflected Shock Bifurcation in a Square Channel", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2011 by University of Chicago. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.\n\nAIAA 2011-646.\n\nThis work was supported through the Basic Energy Sciences and Advanced Scientific Computing Research\nprograms of the Department of Energy Office of Sciences under contract DE-SC0002954. This research used resources of the Argonne Leadership Computing Facility at Argonne National Laboratory, which is\nsupported by the Office of Science of the U.S. Department of Energy under contract DE-AC02-06CH11357.\nAK acknowledges partial NSF support through AST-0709181 and TG-AST090074 grants. The authors thank\nDr. Barry Smith (MCS Division of the Argonne National Laboratory) for helpful advice, and thank Manu\nSharma at the University of Illinois for his contributions to this study.\n\nPublished - 385398.pdf
", "abstract": "We examine the bifurcation of a reflected shock in a three-dimensional, square channel\nthrough numerical simulations using a distributed memory parallel adaptive mesh refinement,\nNavier-Stokes solver with multicomponent equation of state and microscopic transport.\nThe three-dimensional, rather than axisymmetric, geometry introduces considerable\ncomplexity into the flow structures, particularly in the vicinity of the corners. Spanwise\ncross-sections show the boundary layer growth is significantly reduced in the corner regions,\nwhere the shape of the turbulent jet and recirculation regions are modified. This appears\nto be consistent with existing experimental studies which report the boundary layer in the\ncorner region is deformed and the propagation velocity is reduced. A pair of triple points\nand a diagonally-oriented Mach reflection with shear layers directed towards the corner\napex are also observed in the spanwise view.", "date": "2011-01", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Red Hook, NY", "id_number": "CaltechAUTHORS:20140929-131140199", "isbn": "978-1-60086-950-1", "book_title": "49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140929-131140199", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Department of Energy (DOE) Office of Science", "grant_number": "DE-SC0002954" }, { "agency": "Department of Energy (DOE) Office of Science", "grant_number": "DE-AC02-06CH11357" }, { "agency": "NSF", "grant_number": "AST-0709181" }, { "agency": "NSF", "grant_number": "TG-AST090074" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2011-646", "primary_object": { "basename": "385398.pdf", "url": "https://authors.library.caltech.edu/records/y29d6-s9f52/files/385398.pdf" }, "pub_year": "2011", "author_list": "Khokhlov, A. M.; Austin, J. M.; et el." }, { "id": "https://authors.library.caltech.edu/records/06wps-2tc98", "eprint_id": 50399, "eprint_status": "archive", "datestamp": "2023-08-19 05:00:15", "lastmod": "2023-10-17 23:26:05", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Swantek-A-B", "name": { "family": "Swantek", "given": "A. B." } }, { "id": "Duchek-M", "name": { "family": "Duchek", "given": "M." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "J. M." } } ] }, "title": "The Response of Material Heterogeneities to Stress Wave Loading", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2010 The Combustion Institute.\n\nThe authors gratefully acknowledge Prof. John Lambros for \u00b7\nthe generous loan of laboratory equipment and space which\nmade this study possible. We thank Matthew Parker for his\ninitial experiments, Prof. Greg Elliott for valuable input in\nthe PIV measurements, Prof. Jonathan Freund, Dr. Thomas\nJackson, Prof. Carlos Pantano, Dr. Ratnesh Shukla and Prof. Scott Stewart for extensive discussions comparing experiments and simulations, and researchers in the DE-9 division at Los Alamos National Laboratories. This work was supported in part by the US Department of Energy through the University of California under subcontract B523 819 and in part by Air Force Office of Scientific Research under A9550-10-C-0008.", "abstract": "We present dynamic experiments designed to examine the interaction of a loading wave with material heterogeneities; for example, as representatives of oxidizer particles in energetic materials. In our model experiments, we use a gas gun to load a thin sheet of polymer material containing a cylindrical inclusion. We utilize two different types of inclusions; an\nelastomer (polydimethysiloxane) and a liquid of high acoustic impedance (glycerol). Full velocity fields, including the first measurements of this type internal to the inclusion, are achieved with a single frame, two-color particle image velocimetry (PIV) system. Vector and contour plots are presented at different times during the event, as well as cross sectional velocity profiles through the inclusion. Clamping the test samples molds with different torques is found to lead to three-dimensional\neffects in the case of the elastomer.", "date": "2011", "date_type": "published", "publisher": "The Combustion Institute", "place_of_pub": "Pittsburgh, PA", "pagerange": "608-614", "id_number": "CaltechAUTHORS:20141015-100651438", "isbn": "9781617828843", "book_title": "Central States Section of the Combustion Institute Spring Technical Meeting 2010 : Champaign, Illinois, USA, 21-23 March 2010.", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141015-100651438", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Department of Energy (DOE)", "grant_number": "B523819" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-10-C-0008" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "pub_year": "2011", "author_list": "Swantek, A. B.; Duchek, M.; et el." }, { "id": "https://authors.library.caltech.edu/records/3vsap-xw511", "eprint_id": 35594, "eprint_status": "archive", "datestamp": "2023-08-22 01:39:56", "lastmod": "2024-01-13 05:57:07", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Aria-A-I", "name": { "family": "Aria", "given": "Adrianus I." } }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "Morteza" } } ] }, "title": "Effect of Dry Oxidation on the Performance of Carbon Nanotube Arrays Electrochemical Capacitors", "ispublished": "unpub", "full_text_status": "public", "keywords": "energy storage; oxidation; C", "note": "\u00a9 2012 Materials Research Society.\nThis work was supported by The Office of Naval Research under grant number N00014-11-1-0031 and The Fletcher Jones Foundation under grant number 9900600. The authors gratefully\nacknowledge the Charyk Laboratory for Bioinspired Design, Kavli Nanoscience Institute (KNI) and the Molecular Materials Research Center (MMRC) at the California Institute of Technology\nfor access to fabrication and characterization instruments. The authors also acknowledge\nProfessor George Rossman at the Division of Geological and Planetary Sciences of the\nCalifornia Institute of Technology for access to the Raman spectrometer and Melanic Guittet for\nher valuable assistance in conducting the experiment.\n\nPublished - Aria_2012.543.pdf
", "abstract": "In this study, the effect of dry oxidation on the electrochemical properties of carbon nanotube arrays is investigated. Oxygenated surface functional groups were introduced to the arrays by oxygen plasma treatment, where their surface concentrations were varied by controlling the exposure time. The finding presented herein shows an augmentation of nearly thirty times in term of specific capacitance when the arrays are oxidized. Similar behavior is also observed in the non-aqueous electrolytes where the specific capacitance of the oxidized carbon nanotube arrays is measured more than three times higher than that of the pristine ones. However, overexposure to oxygen plasma treatment reverses this effect. At such high oxidation level, the damage to the graphitic structure becomes more pronounced such that the capacitive behavior of the arrays is overshadowed by their resistive behavior. These findings are important for further development of carbon nanotube based electrochemical capacitors.", "date": "2011", "date_type": "published", "publisher": "Materials Research Society", "place_of_pub": "Warrendale, PA", "pagerange": "129-134", "id_number": "CaltechAUTHORS:20121121-082404053", "isbn": "9781605113845", "book_title": "Carbon Nanotubes, Graphene and Related Nanostructures", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121121-082404053", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-11-1-0031" }, { "agency": "Fletcher Jones Foundation", "grant_number": "9900600" } ] }, "local_group": { "items": [ { "id": "Kavli-Nanoscience-Institute" }, { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Yap-Y-K", "name": { "family": "Yap", "given": "Yoke Khin" } } ] }, "doi": "10.1557/opl.2012.543", "primary_object": { "basename": "Aria_2012.543.pdf", "url": "https://authors.library.caltech.edu/records/3vsap-xw511/files/Aria_2012.543.pdf" }, "pub_year": "2011", "author_list": "Aria, Adrianus I. and Gharib, Morteza" }, { "id": "https://authors.library.caltech.edu/records/x15gc-qtw84", "eprint_id": 71859, "eprint_status": "archive", "datestamp": "2023-08-19 04:39:00", "lastmod": "2024-01-13 20:19:07", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Slotine-J-J-E", "name": { "family": "Slotine", "given": "Jean-Jacques" } } ] }, "title": "On synchronization of coupled Hopf-Kuramoto oscillators with phase delays", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2010 IEEE. \n\nDate Added to IEEE Xplore: 22 February 2011. \n\nThis work was supported in part by the Air Force Office of Scientific Research (AFOSR).\n\nPublished - 05717962.pdf
", "abstract": "This paper presents new methods and results on synchronization of coupled Hopf nonlinear oscillators, which are commonly used as the dynamic model of engineered central pattern generators (CPGs). On balanced graphs, any positive coupling gain is proven to induce almost global asymptotic synchronization, and a threshold value for truly global exponential synchronization is also computed. Furthermore, a hierarchical connection between coupled Hopf oscillators and Kuramoto oscillators is identified. Finally, a new result on the synchronization of Kuramoto oscillators with arbitrary time-varying heterogeneous frequencies and delays is derived.", "date": "2010-12", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "3181-3187", "id_number": "CaltechAUTHORS:20161109-075145395", "isbn": "978-1-4244-7746-3", "book_title": "49th IEEE Conference on Decision and Control (CDC)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161109-075145395", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/CDC.2010.5717962", "primary_object": { "basename": "05717962.pdf", "url": "https://authors.library.caltech.edu/records/x15gc-qtw84/files/05717962.pdf" }, "pub_year": "2010", "author_list": "Chung, Soon-Jo and Slotine, Jean-Jacques" }, { "id": "https://authors.library.caltech.edu/records/n9tvr-5xw98", "eprint_id": 50008, "eprint_status": "archive", "datestamp": "2023-08-22 01:31:03", "lastmod": "2023-10-17 22:26:26", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Jackson-T-L", "name": { "family": "Jackson", "given": "Thomas L." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "Joanna M." } } ] }, "title": "Solid Propulsion: Motor Interior Ballistics - Modeling\n and Design", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "solid propellants; propellant morphology; stability; agglomeration; two-phase flow; combustion; chamber pressure; burn rate; aluminum", "note": "\u00a9 2010 John Wiley & Sons, Ltd.", "abstract": "Virtual engineering, a combination of numerical simulation,\nempiricalism, and small-scale testing for validation, is useful\nfor motor design and is rapidly becoming the standard tool\nfor designing new motors. Appropriate physics-based models\nare required for the propellant, chamber, nozzle, and plume\nregions. We discuss some modern developments of physics-based\nmodels used in virtual engineering, and comment on\ncurrent trends. We anticipate that virtual engineering will one\nday be used at the design stage, with full scale motor firings\nreserved as a final qualification test.", "date": "2010-12", "date_type": "published", "publisher": "Wiley", "place_of_pub": "Hoboken, NJ", "pagerange": "1103-1111", "id_number": "CaltechAUTHORS:20140924-144130038", "isbn": "978-0-470-75440-5", "book_title": "Encyclopedia of Aerospace Engineering", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140924-144130038", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Blockley-R", "name": { "family": "Blockley", "given": "Richard" } }, { "id": "Shyy-W", "name": { "family": "Shyy", "given": "Wei" } } ] }, "pub_year": "2010", "author_list": "Jackson, Thomas L. and Austin, Joanna M." }, { "id": "https://authors.library.caltech.edu/records/a3rww-4tk22", "eprint_id": 72490, "eprint_status": "archive", "datestamp": "2023-08-19 04:39:16", "lastmod": "2023-10-23 22:39:32", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chang-Insu", "name": { "family": "Chang", "given": "Insu" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Blackmore-L", "name": { "family": "Blackmore", "given": "Lars" } } ] }, "title": "Cooperative Control with Adaptive Graph Laplacians for Spacecraft Formation Flying", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2010 IEEE. \n\nDate Added to IEEE Xplore: 22 February 2011. \n\nPart of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.\n\nPublished - ChangChungBlackmore_CDC2010_Final.pdf
", "abstract": "This paper investigates exact nonlinear dynamics and cooperative control for spacecraft formation flying with Earth oblateness (J2 perturbation) and atmospheric drag effects. The nonlinear dynamics for chief and deputy motions are derived by using Gauss' variational equation and the Euler-Lagrangian formulation, respectively. The proposed cooperative control employs adaptive time-varying Laplacian gains. The tracking and diffusive coupling gains are adapted by the synchronization/tracking errors and distance-based connectivity, thereby defining a time-varying network topology. Moreover, the proposed method relaxes the network structure requirement and permits an unbalanced graph. Nonlinear stability is proven by contraction analysis and incremental input-to-state stability. Numerical examples show the effectiveness of the proposed method.", "date": "2010-12", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "4926-4933", "id_number": "CaltechAUTHORS:20161201-084722017", "isbn": "978-1-4244-7746-3", "book_title": "49th IEEE Conference on Decision and Control (CDC)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161201-084722017", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/CDC.2010.5717516", "primary_object": { "basename": "ChangChungBlackmore_CDC2010_Final.pdf", "url": "https://authors.library.caltech.edu/records/a3rww-4tk22/files/ChangChungBlackmore_CDC2010_Final.pdf" }, "pub_year": "2010", "author_list": "Chang, Insu; Chung, Soon-Jo; et el." }, { "id": "https://authors.library.caltech.edu/records/1pkct-w6157", "eprint_id": 22999, "eprint_status": "archive", "datestamp": "2023-08-22 00:35:05", "lastmod": "2024-01-13 05:13:06", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Patterson-K", "name": { "family": "Patterson", "given": "Keith" } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" }, { "id": "Breckinridge-J-B", "name": { "family": "Breckinridge", "given": "James" }, "orcid": "0000-0002-9488-098X" } ] }, "title": "Shape correction of thin mirrors in a reconfigurable modular space telescope", "ispublished": "unpub", "full_text_status": "public", "keywords": "thin mirrors; segmented telescopes; shape correction; image quality", "note": "\u00a9 2010 SPIE.\n\nThis research was sponsored by the Keck Institute for Space Studies (KISS). We would like to thank Dr Mark\nLake and Dr Matt Mountain for stimulating comments during the initial formulation of the concepts presented\nin this paper. Professor Chiara Daraio and Dr Abha Misra have kindly allowed us to present some early results\nfrom their research on low CTE, bimetallic mirror films. The nanosatellite mission proposed in Section 4 is\na collaboration between Caltech and the University of Surrey. We acknowledge the contribution of Dr Craig\nUnderwood (University of Surrey, UK) to the formulation of this mission concept.\n\nPublished - Patterson2010p13182Adaptive_Optics_Systems_Pts_1-3.pdf
", "abstract": "In order to facilitate the construction of future large space telescopes, the development of low cost, low mass\nmirrors is necessary. However, such mirrors suffer from a lack of structural stability, stiffness, and shape accuracy.\nActive materials and actuators can be used to alleviate this deficiency. For observations in the visible wavelengths,\nthe mirror surface must be controlled to an accuracy on the order of tens of nanometers. This paper presents\nan exploration of several mirror design concepts and compares their effectiveness at providing accurate shape\ncontrol. The comparison test is the adjustment of a generic mirror from its manufactured spherical shape to the\nshape required by various off-axis mirrors in a segmented primary mirror array. A study of thermal effects is\nalso presented and, from these results, a recommended design is chosen.", "date": "2010-08-10", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "Art. No. 773121", "id_number": "CaltechAUTHORS:20110321-085232350", "isbn": "978-0-81948-221-1", "book_title": "Space telescopes and instrumentation 2010 : optical, infrared, and millimeter wave", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110321-085232350", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Keck Institute for Space Studies (KISS)" } ] }, "local_group": { "items": [ { "id": "Keck-Institute-for-Space-Studies" }, { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Oschmann-J-M", "name": { "family": "Oschmann", "given": "Jacobus M." } }, { "id": "Clampin-M-C", "name": { "family": "Clampin", "given": "Mark C." } }, { "id": "MacEwen-H-A", "name": { "family": "MacEwen", "given": "Howard A." } } ] }, "doi": "10.1117/12.861442", "primary_object": { "basename": "Patterson2010p13182Adaptive_Optics_Systems_Pts_1-3.pdf", "url": "https://authors.library.caltech.edu/records/1pkct-w6157/files/Patterson2010p13182Adaptive_Optics_Systems_Pts_1-3.pdf" }, "pub_year": "2010", "author_list": "Patterson, Keith; Pellegrino, Sergio; et el." }, { "id": "https://authors.library.caltech.edu/records/ex89c-yph27", "eprint_id": 73159, "eprint_status": "archive", "datestamp": "2023-08-19 03:24:37", "lastmod": "2023-10-24 15:05:10", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Paranjape-A-A", "name": { "family": "Paranjape", "given": "Aditya" }, "orcid": "0000-0002-3164-3215" }, { "id": "Chakravarthy-A", "name": { "family": "Chakravarthy", "given": "Animesh" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Hilton-H-H", "name": { "family": "Hilton", "given": "Harry H." } } ] }, "title": "Performance and Stability of an Agile Tail-less MAV with Flexible Articulated Wings", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2010 American Institute of Aeronautics and Astronautics. \n\nThis project was supported by the Air Force Office of Scientific Research (AFOSR) under the Young Investigator Award Program (Grant No. FA95500910089) monitored by Dr. W. Larkin. The original problem was posed by Dr. Gregg Abate (AFRL). This paper also benefitted from stimulating discussions with Mr. Johnny Evers (AFRL).\n\nPublished - ParanjapeFlexAFM10.pdf
", "abstract": "This paper considers the problems of (a) modelling the \night mechanics of a tail-less MAV equipped with \nexible articulated wings, and (b) the analysis of its turning performance. The wings are assumed to have two degrees of freedom - heave and twist. They are\nassumed to be actuated from the root, which is the abstraction of an experimental control mechanism being developed by the authors. The dihedral and twist angles at the wing root are controlled. A novel actuator concept of axial tension to control wing stiffness has been\nexplored in this paper. It is shown that axial tension in the wing has a significant effect on the turning performance of the aircraft, although the effect is not uniformly beneficial in nature. The effect of \nexibility on the steady state turning performance of the aircraft has been demonstrated by comparing it with that of a rigid aircraft, and with that of a similar aircraft possessing a wing with different elastic properties.", "date": "2010-08", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2010-7937", "id_number": "CaltechAUTHORS:20161222-121459009", "isbn": "978-1-62410-151-9", "book_title": "AIAA Atmospheric Flight Mechanics Conference 2010", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161222-121459009", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA95500910089" } ] }, "other_numbering_system": { "items": [ { "id": "2010-7937", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2010-7937", "primary_object": { "basename": "ParanjapeFlexAFM10.pdf", "url": "https://authors.library.caltech.edu/records/ex89c-yph27/files/ParanjapeFlexAFM10.pdf" }, "pub_year": "2010", "author_list": "Paranjape, Aditya; Chakravarthy, Animesh; et el." }, { "id": "https://authors.library.caltech.edu/records/yw6tp-dxx12", "eprint_id": 73056, "eprint_status": "archive", "datestamp": "2023-08-19 03:24:31", "lastmod": "2023-10-24 15:00:09", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chakravarthy-A", "name": { "family": "Chakravarthy", "given": "Animesh" } }, { "id": "Paranjape-A-A", "name": { "family": "Paranjape", "given": "Aditya" }, "orcid": "0000-0002-3164-3215" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Control Law Design for Perching an Agile MAV with Articulated Wings", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2010 American Institute of Aeronautics and Astronautics, Inc. \n\nThis project was supported by the Air Force Office of Scientific Research (AFOSR) under the Young Investigator Award Program (Grant No. FA95500910089) monitored by Dr. W. Larkin. The original problem was posed by Dr. Gregg Abate (AFRL). This paper also benefitted from stimulating discussions with Mr. Johnny Evers (AFRL).\n\nPublished - gnc_perching_paper.pdf
", "abstract": "This paper explores the use of variable wing dihedral and variable wing twist (in conjunction\nwith a conventional horizontal elevator) to control an aircraft performing a perching\nmaneuver. A choice of controller architecture wherein the dihedral is employed in the\nforward path and the elevator and twist are employed in the feedback path, is considered.\nThe aircraft is modeled as a multivariable linear time-varying system. A specific perching\ntrajectory is considered; and the open-loop aircraft is longitudinally unstable for a segment\nof this perching trajectory and lateral-directionally unstable for the entire perching trajectory.\nA multivariable time-varying controller is designed to efficiently stabilize the aircraft\nas well as reject longitudinal-lateral-directional wind disturbances, while closely tracking\nthe reference perching trajectory.", "date": "2010-08", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics (AIAA)", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2010-7934", "id_number": "CaltechAUTHORS:20161221-084856591", "isbn": "978-1-62410-151-9", "book_title": "AIAA Atmospheric Flight Mechanics Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161221-084856591", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA95500910089" } ] }, "collection": "CaltechAUTHORS", "other_numbering_system": { "items": [ { "id": "2010-7934", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT", "value": "GALCIT" } ] }, "doi": "10.2514/6.2010-7934", "primary_object": { "basename": "gnc_perching_paper.pdf", "url": "https://authors.library.caltech.edu/records/yw6tp-dxx12/files/gnc_perching_paper.pdf" }, "pub_year": "2010", "author_list": "Chakravarthy, Animesh; Paranjape, Aditya; et el." }, { "id": "https://authors.library.caltech.edu/records/vheg5-rce13", "eprint_id": 73009, "eprint_status": "archive", "datestamp": "2023-08-19 03:24:22", "lastmod": "2023-10-24 14:57:15", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Dorothy-M-R", "name": { "family": "Dorothy", "given": "Michael" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Methodological Remarks on CPG-Based Control of Flapping Flight", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2010 American Institute of Aeronautics and Astronautics, Inc.\n\nPublished - FlappingFlightAFM10.pdf
", "abstract": "This paper is a companion to Chung and explores the applications of neurobiologically inspired control systems in the form of Central Pattern Generators (CPG) to control\nflapping flight dynamics. We introduce two-layer CPGs to mimic current hypotheses of mammalian studies. It is shown that symmetry breaking to initiate and recover from a turning maneuver is an effective control strategy. Attempts at dissociating slow dynamics are shown and preliminary comparisons of wing motions between biological fliers and\nartificial CPG networks are made.", "date": "2010-08", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No.-2010", "id_number": "CaltechAUTHORS:20161220-152114592", "isbn": "978-1-62410-151-9", "book_title": "AIAA Atmospheric Flight Mechanics Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161220-152114592", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2010-7634", "primary_object": { "basename": "FlappingFlightAFM10.pdf", "url": "https://authors.library.caltech.edu/records/vheg5-rce13/files/FlappingFlightAFM10.pdf" }, "pub_year": "2010", "author_list": "Dorothy, Michael and Chung, Soon-Jo" }, { "id": "https://authors.library.caltech.edu/records/9c5jr-hvq32", "eprint_id": 73011, "eprint_status": "archive", "datestamp": "2023-08-19 03:24:27", "lastmod": "2023-10-24 14:57:24", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Paranjape-A-A", "name": { "family": "Paranjape", "given": "Aditya A." }, "orcid": "0000-0002-3164-3215" }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Flight Mechanics of a Tail-less Articulated Wing Aircraft", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2010 American Institute of Aeronautics and Astronautics, Inc. \n\nThis project was supported by the Air Force Office of Scientific Research (AFOSR) under the Young Investigator Award Program (Grant No. FA95500910089) monitored by Dr. W. Larkin. The original problem was posed by Dr. Gregg Abate (AFRL). This paper also benefitted from stimulating discussions with Mr. Johnny Evers (AFRL). Dr. Animesh Chakravarthy (Univ. of Florida REEF) provided useful feedback and comments from the very inception of this work, and helped refine the paper to the present state. The authors also thank undergraduate research assistants James Holtman, Joe Kim, Andrew Meister, Daniel Park and Jonathon Yong whose hard work resulted in an experimental MAV for evaluating the ideas described in this paper.\n\nPublished - FightMechanicsAFM2010.pdf
", "abstract": "This paper explores the flight mechanics of a Micro Aerial Vehicle (MAV) without a vertical tail. The key to stability and control of such an aircraft lies in the ability to control the twist and dihedral angles of both wings independently. Specifically, asymmetric dihedral can be used to control yaw whereas antisymmetric twist can be used to control roll. It has been demonstrated that wing dihedral angles can regulate sideslip and speed during a turn maneuver. The role of wing dihedral in the aircraft's longitudinal performance has been explored. It has been shown that dihedral angle can be varied symmetrically to achieve limited control over aircraft speed even as the angle of attack and flight path angle are varied. A rapid descent and perching maneuver has been used to illustrate the longitudinal agility of the aircraft. This paper lays part of the foundation for the design and stability analysis of an agile flapping wing aircraft capable of performing rapid maneuvers while gliding in a constrained environment.", "date": "2010-08", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics (AIAA)", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2010-7633", "id_number": "CaltechAUTHORS:20161220-153007449", "isbn": "978-1-62410-151-9", "book_title": "AIAA Atmospheric Flight Mechanics Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161220-153007449", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA95500910089" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2010-7633", "primary_object": { "basename": "FightMechanicsAFM2010.pdf", "url": "https://authors.library.caltech.edu/records/9c5jr-hvq32/files/FightMechanicsAFM2010.pdf" }, "pub_year": "2010", "author_list": "Paranjape, Aditya A. and Chung, Soon-Jo" }, { "id": "https://authors.library.caltech.edu/records/c091n-vsa98", "eprint_id": 50104, "eprint_status": "archive", "datestamp": "2023-08-19 02:43:21", "lastmod": "2023-10-17 22:31:01", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Flaherty-W", "name": { "family": "Flaherty", "given": "W." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "J. M." } } ] }, "title": "Effect of Concave Wall Geometry on Heat Transfer in Hypersonic Boundary Layers", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2010 by University of Illinois. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.\n\nAIAA 2010-4986.\n\n\nThis work was funded through the Air Force Office of Scientific Research FA9550-08-1-0172 with Dr. John\nSchmisseur as program manager. We are grateful to the Caltech T5 group, Prof. Hans Hornung, Bahram\nValiferdowski, Drs Eric Marineau, Adam Rasheed, and Ivett Leyva for their help with thermocouples. The\nauthors would like to thank Ryan Fontaine, Manu Sharma, and Andy Swantek for their help with this work.\n\nPublished - 385400.pdf
", "abstract": "Heat transfer measurements are made to investigate the effects of concave surface curvature on a high-stagnation enthalpy boundary layer in a Mach 5.1 flow. Experiments are\ncarried out using two curved models with 16 and 25 degree turning angles, and baseline\nplanar models (at plate and linear ramp) for comparative study. Streamwise and spanwise\ncross-sections are obtained. Significant destabilization of the boundary layer is observed\nover the adverse pressure gradient geometries. For the curved surfaces, the heat flux distribution appears to exhibit a quadratic dependence with streamwise distance, in contrast\nwith the linear dependence observed on the linear ramp.", "date": "2010-06", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "id_number": "CaltechAUTHORS:20140929-142500176", "isbn": "978-1-61738-922-1", "book_title": "40th Fluid Dynamics Conference and Exhibit", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140929-142500176", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-08-1-0172" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2010-4986", "primary_object": { "basename": "385400.pdf", "url": "https://authors.library.caltech.edu/records/c091n-vsa98/files/385400.pdf" }, "pub_year": "2010", "author_list": "Flaherty, W. and Austin, J. M." }, { "id": "https://authors.library.caltech.edu/records/4cdca-4t956", "eprint_id": 50102, "eprint_status": "archive", "datestamp": "2023-08-19 02:43:15", "lastmod": "2023-10-17 22:30:59", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Orescanin-M-M", "name": { "family": "Orescanin", "given": "M. M." } }, { "id": "Prisco-D", "name": { "family": "Prisco", "given": "D." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "J. M." } } ] }, "title": "Exhaust of Underexpanded Jets from Finite Reservoirs", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2010 by University of Illinois. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.\n\nAIAA 2010-5108.\n\nThe authors gratefully acknowledge interactions with Prof. Susan Kieffer in this study. This work was\nsupported in part by NSF grant EAR06-09712, NSF grant SK2008-0035 8 ANTC and Charles R. Walgreen\nendowed funds to Susan W. Kieffer. We are grateful to Dr. James Quirk for the use of his code Amrita. We\nthank David Buchta for performing modeling runs with a different code to cross-check our results.\n\nPublished - 385579.pdf
", "abstract": "We examine the response of an underexpanded jet to a depleting, finite reservoir with\nexperiments and simulations. An open-ended shock tube facility with variable reservoir\nlength is used to obtain images of nitrogen and helium jet structures at successive instances\nduring the blowdown from initial pressure ratios of up to 250. The reservoir and ambient\npressures are simultaneously measured to obtain the instantaneous pressure ratio. We\nestimate the time-scales for jet formation and reservoir depletion as a function of the specific\nheat ratio of the gas and the initial pressure ratio. The jet structure formation time-scale\nis found to become approximately independent of pressure ratio for ratios greater than\n50. In the present work, no evidence of time-dependence in the Mach disk shock location\nis observed for rates of pressure decrease associated with isentropic blowdown of a finite\nreservoir while the pressure ratio is greater than 15. The shock location in the finite-\nreservoir jet can be calculated from an existing empirical fit to infinite-reservoir jet data\nevaluated at the instantaneous reservoir pressure. For pressure ratios below 15, however,\nthe present data deviate from a compilation of data for infinite-reservoir jets. A new fit\nis obtained to data in the lower pressure regime. The self-similarity of the jet structure\nis quantified and departure from similarity is noted to begin at pressure ratios lower than\nabout 15, approximately the same ratio which limits existing empirical fits.", "date": "2010-06", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "id_number": "CaltechAUTHORS:20140929-134308323", "isbn": "978-1-61738-922-1", "book_title": "40th Fluid Dynamics Conference and Exhibit", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140929-134308323", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR06-09712" }, { "agency": "NSF", "grant_number": "SK2008-0035 8 ANTC" }, { "agency": "Charles R. Walgreen endowed funds" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2010-5108", "primary_object": { "basename": "385579.pdf", "url": "https://authors.library.caltech.edu/records/4cdca-4t956/files/385579.pdf" }, "pub_year": "2010", "author_list": "Orescanin, M. M.; Prisco, D.; et el." }, { "id": "https://authors.library.caltech.edu/records/kbb2q-gk954", "eprint_id": 103657, "eprint_status": "archive", "datestamp": "2023-08-19 02:17:01", "lastmod": "2023-10-20 16:34:04", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Theil-F", "name": { "family": "Theil", "given": "Florian" } }, { "id": "Sullivan-T", "name": { "family": "Sullivan", "given": "Tim" } }, { "id": "Koslovski-M", "name": { "family": "Koslovski", "given": "Marisol" } }, { "id": "Ortiz-M", "name": { "family": "Ortiz", "given": "Michael" }, "orcid": "0000-0001-5877-4824" } ] }, "title": "Dissipative Systems in Contact with a Heat Bath: Application to Andrade Creep", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2010 Springer Science+Business Media B.V. \n\nFirst Online: 21 April 2010.", "abstract": "We develop a theory of statistical mechanics for dissipative systems governed by equations of evolution that assigns probabilities to individual trajectories of the system. The theory is made mathematically rigorous and leads to precise predictions regarding the behavior of dissipative systems at finite temperature. Such predictions include the effect of temperature on yield phenomena and rheological time exponents. The particular case of an ensemble of dislocations moving in a slip plane through a random array of obstacles is studied numerically in detail. The numerical results bear out the analytical predictions regarding the mean response of the system, which exhibits Andrade creep.", "date": "2010-04-21", "date_type": "published", "publisher": "Springer", "place_of_pub": "Dordrecht", "pagerange": "261-272", "id_number": "CaltechAUTHORS:20200603-073605619", "isbn": "978-90-481-9194-9", "book_title": "IUTAM Symposium on Variational Concepts with Applications to the Mechanics of Materials", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200603-073605619", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "collection": "CaltechAUTHORS", "local_group": { "items": [ { "id": "GALCIT", "value": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Hackl-K", "name": { "family": "Hackl", "given": "Klaus" } } ] }, "doi": "10.1007/978-90-481-9195-6_20", "pub_year": "2010", "author_list": "Theil, Florian; Sullivan, Tim; et el." }, { "id": "https://authors.library.caltech.edu/records/72dm2-bhb02", "eprint_id": 99290, "eprint_status": "archive", "datestamp": "2023-08-19 02:08:32", "lastmod": "2023-10-18 18:12:42", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Stohlman-O-R", "name": { "family": "Stohlman", "given": "O. R." } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "S." }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Shape Accuracy of a Joint-Dominated Deployable Mast", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2010 by O. Stohlman and S. Pellegrino. Published by the American Institute of Aeronautics and Astronautics, Inc. with permission.\n\nAccepted Version - StohlmanAIAA2010.pdf
", "abstract": "This paper presents a study to capture and model friction related changes in the un-loaded configuration of deployable masts with articulated joints. A finite model of a rep-resentative mast structure is described. This model includes a detailed treatment of the latching mechanism. The parameters of the computational model are based on direct mea-surements on components of a physical model. The moment-rotation relationship for a complete single bay of the physical model has been measured and the overall behavior is predicted well by the model, however the model predicts the residual rotation at zero moment to be zero and so it is concluded that a more refined model for the latch will need to be developed.", "date": "2010-04", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2010-2605", "id_number": "CaltechAUTHORS:20191016-085828334", "isbn": "978-1-60086-961-7", "book_title": "51st AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191016-085828334", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "collection": "CaltechAUTHORS", "other_numbering_system": { "items": [ { "id": "2010-2605", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT", "value": "GALCIT" } ] }, "doi": "10.2514/6.2010-2605", "primary_object": { "basename": "StohlmanAIAA2010.pdf", "url": "https://authors.library.caltech.edu/records/72dm2-bhb02/files/StohlmanAIAA2010.pdf" }, "pub_year": "2010", "author_list": "Stohlman, O. R. and Pellegrino, S." }, { "id": "https://authors.library.caltech.edu/records/d5bry-t8186", "eprint_id": 99293, "eprint_status": "archive", "datestamp": "2023-08-19 02:08:40", "lastmod": "2023-10-18 18:12:46", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Mallikarachchi-H-M-Y-C", "name": { "family": "Mallikarachchi", "given": "H. M. Y. C." } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "S." }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Optimized Designs of Composite Booms with Tape Spring Hinges", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2010 by H.M.Y.C Mallikarachchi and S. Pellegrino. Published by the American Institute of Aeronautics and Astronautics, Inc. with permission.", "abstract": "This paper presents an optimization study of a lightweight hinge consisting of a thin walled tube made of carbon fiber reinforced plastic with two longitudinal slots. The slot geometry is parameterized in terms of slot length, width and end circle diameter. Previously developed numerical simulation techniques to analyze the folding and deployment of this kind of hinges are used to carry out a series of parametric studies. The maximum strains are estimated by using the mid-surface strain and curvature obtained from a macro model of the structure to a micro model and averaging the strains over a half a tow width in the micro model. A maximum strain failure criterion is used for failure analysis. The optimization study is focused on finding a hinge design that can be folded 180 deg with the shortest possible slot length. Simulations show that the maximum strains can be significantly reduced by allowing the end-cross sections to deform freely. Based on simulations a failure critical model and a failure safe model were selected and experimentally validated. The optimized design is six times stiffer in torsion, twice stiffer axially and stores two and a half times more strain energy than the previously considered design.", "date": "2010-04", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2010-2750", "id_number": "CaltechAUTHORS:20191016-092056718", "isbn": "978-1-60086-961-7", "book_title": "51st AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191016-092056718", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "collection": "CaltechAUTHORS", "other_numbering_system": { "items": [ { "id": "2010-2750", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT", "value": "GALCIT" } ] }, "doi": "10.2514/6.2010-2750", "pub_year": "2010", "author_list": "Mallikarachchi, H. M. Y. C. and Pellegrino, S." }, { "id": "https://authors.library.caltech.edu/records/qf3qy-hb666", "eprint_id": 99292, "eprint_status": "archive", "datestamp": "2023-08-19 02:08:36", "lastmod": "2023-10-18 18:12:44", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kwok-Kawai", "name": { "family": "Kwok", "given": "Kawai" }, "orcid": "0000-0001-6876-4267" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Shape Recovery of Viscoelastic Deployable Structures", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2010 by K. Kwok and S. Pellegrino. Published by the American Institute of Aeronautics and Astronautics, Inc. with permission.\n\nAccepted Version - KwokAIAA2010.pdf
", "abstract": "The paper investigates the shape recovery behavior of a simple beam and a tape spring made of LDPE under prescribed deformation history at room temperature. The linear viscoelastic material properties of LDPE were measured via creep tests. An analysis of a LDPE beam under four-point bending with an imposed history of vertical deflection and reaction force was performed. A theoretical solution was constructed by employing the Alfrey's Correspondence Principle to the Euler-Bernoulli beam equation. The result was validated against a four-point bending experiment and a detailed nonlinear finite element simulation. Excellent agreement was obtained between theory, experiments and numerical simulations. A LDPE tape spring was fabricated and tested to provide an example of a simple deployable structure that recovers its deployed shape through a viscoelastic process for both equal sense and opposite sense folding.", "date": "2010-04", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2010-2606", "id_number": "CaltechAUTHORS:20191016-090847709", "isbn": "978-1-60086-961-7", "book_title": "51st AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191016-090847709", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "collection": "CaltechAUTHORS", "other_numbering_system": { "items": [ { "id": "2010-2606", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT", "value": "GALCIT" } ] }, "doi": "10.2514/6.2010-2606", "primary_object": { "basename": "KwokAIAA2010.pdf", "url": "https://authors.library.caltech.edu/records/qf3qy-hb666/files/KwokAIAA2010.pdf" }, "pub_year": "2010", "author_list": "Kwok, Kawai and Pellegrino, Sergio" }, { "id": "https://authors.library.caltech.edu/records/611ag-6hw42", "eprint_id": 98934, "eprint_status": "archive", "datestamp": "2023-08-19 01:23:05", "lastmod": "2023-10-18 17:44:35", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Maddalena-L", "name": { "family": "Maddalena", "given": "Luca" } }, { "id": "Dimotakis-P-E", "name": { "family": "Dimotakis", "given": "Paul E." } } ] }, "title": "On the Effects of Transverse-Jet Injection into a Supersonic Shear Layer", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2010 American Institute of Aeronautics and Astronautics.", "abstract": "This paper reports on observations in supersonic flow experiments conducted in an expansion-turn geometry, augmented by inclined-jet injection, in the Supersonic Shear Layer (S^3L) facility at Caltech. The experiments, designed to exploit hydrodynamic instabilities in compressible shear layers, were conducted in a non-reacting environment and at moderate compressibility. A shear layer is formed between a supersonic upper stream (M_1=1.5) and a subsonic lower stream (U_R=8.5 m/s) injected at an angle \u03b1 = 30\u00b0 with respect to the horizontal. The coupling of streamwise vortices generated by 5 jets inclined at 30\u00b0 with respect to the free-stream and the shear layer was investigated. The Color schlieren images illustrate some of the phenomenology associated with transverse-jet injection and shear-layer interaction, and characterize the jet influence on shear-layer entrainment. A substantial increase of the shear layer thickness compared to the unperturbed case (without transverse jets) is reported for a jet-to-freestream momentum flux ratio, q\u0304, of 2.", "date": "2010-01-04", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2010-755", "id_number": "CaltechAUTHORS:20190930-110458086", "isbn": "9781600869594", "book_title": "48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190930-110458086", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "collection": "CaltechAUTHORS", "other_numbering_system": { "items": [ { "id": "2010-755", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT", "value": "GALCIT" } ] }, "doi": "10.2514/6.2010-755", "pub_year": "2010", "author_list": "Maddalena, Luca and Dimotakis, Paul E." }, { "id": "https://authors.library.caltech.edu/records/9a37y-pbk23", "eprint_id": 98932, "eprint_status": "archive", "datestamp": "2023-08-19 01:23:02", "lastmod": "2023-10-18 17:44:28", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Marineau-E-C", "name": { "family": "Marineau", "given": "Eric C." } }, { "id": "Laurence-S-J", "name": { "family": "Laurence", "given": "Stuart J." } }, { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "Hans G." }, "orcid": "0000-0002-4903-8419" } ] }, "title": "Apollo-Shaped Capsule Boundary Layer Transition at High-Enthalpy in T5", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2010 American Institute of Aeronautics and Astronautics.", "abstract": "An investigation of the boundary layer transition on a 7-inch Apollo-shaped capsule heatshield at high enthalpy was performed in the T5 Hypervelocity Shock Tunnel at GAL-CIT. Three series of tests on 2 models for a total 57 shots were performed in air at angles-of-attack of 20-deg and 28-deg for stagnation enthalpies between 7 and 20 MJ/kg and stagnation pressures between 20 and 60 MPa. The free-stream Reynolds number based on model diameter was between 0.3 and 0.9 million. A trip insert with 25 0.05-inch square \"pizza box\" roughness elements located at 0.345-inch below the heat shield geometric cen- ter was used to promote transition on the leeside of the model. Trip heights of 0.007, 0.010 and 0.015 inch were used. Tests were performed with and without trips to evaluate the turbulent heating augmentation. For the highest Reynolds number condition, natural transition occurred on the leeside at both angle of attacks. The most aggressive trips appear to have generated a fully turbulent ows over the leeside of for the high enthalpy conditions at 17 MJ/kg.", "date": "2010-01-04", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2010-446", "id_number": "CaltechAUTHORS:20190930-110457864", "isbn": "9781600869594", "book_title": "48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190930-110457864", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "collection": "CaltechAUTHORS", "other_numbering_system": { "items": [ { "id": "2010-446", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT", "value": "GALCIT" } ] }, "doi": "10.2514/6.2010-446", "pub_year": "2010", "author_list": "Marineau, Eric C.; Laurence, Stuart J.; et el." }, { "id": "https://authors.library.caltech.edu/records/6e8fm-4xe77", "eprint_id": 98938, "eprint_status": "archive", "datestamp": "2023-08-19 01:23:09", "lastmod": "2023-10-18 17:44:44", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Marineau-E-C", "name": { "family": "Marineau", "given": "Eric C." } }, { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "Hans G." }, "orcid": "0000-0002-4903-8419" } ] }, "title": "Study of Bow-Shock Wave Unsteadiness in Hypervelocity Flow from Reservoir Fluctuations", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2010 American Institute of Aeronautics and Astronautics, Inc.", "abstract": "The unsteadiness of the bow-shock wave in front of a 7-inch diameter Apollo-shaped capsule was measured in the T5 hypervelocity shock tunnel at GALCIT. The pressure fluctuations in the reservoir generate expansion and compression waves traveling down the nozzle which interact with the bow-shock in front of the model. The resulting bow-shock displacement is measured using a high-speed Schlieren system where the shock position is extracted using a sub-pixel tracking algorithm. Oscillations of the shock position with amplitudes between \u00b11% to \u00b15% of the standoff distance are measured. The power spectrum of the bow-shock motion displays frequencies in the 10 kHZ range corresponding to the frequency content of the pressure fluctuations measured in the reservoir. The RMS free stream pressure disturbances in that frequency range are estimated to be between 3.5% and 7%. Simulations of the effect of acoustic waves on spheres were used to give a crude estimate of the facility noise level in the 10 kHz range.", "date": "2010-01-04", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2010-382", "id_number": "CaltechAUTHORS:20190930-110458533", "isbn": "9781600869594", "book_title": "48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190930-110458533", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "collection": "CaltechAUTHORS", "other_numbering_system": { "items": [ { "id": "2010-382", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT", "value": "GALCIT" } ] }, "doi": "10.2514/6.2010-382", "pub_year": "2010", "author_list": "Marineau, Eric C. and Hornung, Hans G." }, { "id": "https://authors.library.caltech.edu/records/h4vky-8z147", "eprint_id": 50197, "eprint_status": "archive", "datestamp": "2023-08-19 01:18:55", "lastmod": "2023-10-17 22:50:32", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Flaherty-W", "name": { "family": "Flaherty", "given": "W." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "J. M." } } ] }, "title": "Comparative surface heat transfer measurements in\n hypervelocity flow", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2010 by University of Illinois at Urbana-Champaign. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.\n\nAIAA 2010-671.\n\nThis work was funded through the Air Force Office of Scientific Research FA9550-08-1-0172 with Dr.\nJohn Schmisseur as program manager. We are grateful to the Caltech T5 group, Prof. Hans Hornung,\nBahram Valiferdowski, Drs Eric Marineau, Adam Rasheed, and Ivett Leyva for their valuable help with\nthermocouples and to Lt. Col. Prof. Russell Adelgren for useful discussions on thin film gages. The authors\nwould like to thank Ryan Fontaine, Manu Sharma, and Andy Swantek for their help with this work.\n\nPublished - 385908.pdf
", "abstract": "Experimental heat flux measurements are made using both thermocouple and thin film\ngages in high-temperature, hypersonic flows. Thermocouple and thin film gages have individually\nbeen extensively used in relatively high and low enthalpy conditions respectively.\nIn this study, three test conditions with varying (intermediate) stagnation enthalpies, Mach\nand Reynolds numbers are created in an expansion tube facility, and temperature histories\nand heat flux measurements obtained using the two gage types are directly compared.\nGage performance in terms of survivability, response, uncertainty, and signal-to-noise ratio\nis assessed for both blunt body and flat plate models.", "date": "2010-01", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "id_number": "CaltechAUTHORS:20141006-082211395", "isbn": "978-1-60086-959-4", "book_title": "48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141006-082211395", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-08-1-0172" } ] }, "collection": "CaltechAUTHORS", "local_group": { "items": [ { "id": "GALCIT", "value": "GALCIT" } ] }, "doi": "10.2514/6.2010-671", "primary_object": { "basename": "385908.pdf", "url": "https://authors.library.caltech.edu/records/h4vky-8z147/files/385908.pdf" }, "pub_year": "2010", "author_list": "Flaherty, W. and Austin, J. M." }, { "id": "https://authors.library.caltech.edu/records/bgh2d-qfy15", "eprint_id": 99296, "eprint_status": "archive", "datestamp": "2023-08-19 01:20:22", "lastmod": "2023-10-18 18:12:53", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Wagnild-R-M", "name": { "family": "Wagnild", "given": "Ross M." } }, { "id": "Candler-G-V", "name": { "family": "Candler", "given": "Graham V." } }, { "id": "Leyva-I-A", "name": { "family": "Leyva", "given": "Ivett A." } }, { "id": "Jewell-J-S", "name": { "family": "Jewell", "given": "Joseph S." }, "orcid": "0000-0002-4047-9998" }, { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "Hans G." }, "orcid": "0000-0002-4903-8419" } ] }, "title": "Carbon Dioxide Injection for Hypervelocity Boundary Layer Stability", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2010 by Ross Wagnild. Published by the American Institute of Aeronautics and Astronautics, Inc. with permission.\n\nAccepted Version - AIAA-2010-1244.pdf
", "abstract": "An approach for introducing carbon dioxide as a means or stabilizing a hypervelocity boundary layer over a slender bodied vehicle is investigated through the use of numerical simulations. In the current study, two different test bodies are examined. The first is a five-degree-half-angle cone currently under research at the GALCIT T5 Shock Tunnel with a 4 cm porous wall insert used to transpire gas into the boundary layer. The second test body is a similar cone with a porous wall over a majority of cone surface. Computationally, the transpiration is performed using an axi-symmetric flow simulation with wall-normal blowing. The effect of the injection and the transition location are gauged by solving the parabolized stability equations and using the semi-empirical e^N method. The results show transition due to the injection for the first test body and a delay in the transition location for the second test body as compared to a cone without injection under the same flight conditions. The mechanism for the stabilizing effect of carbon dioxide is also explored through selectively applying non-equilibrium processes to the stability analysis. The results show that vibrational non-equilibrium plays a role in reducing disturbance amplification; however, other factors also contribute.", "date": "2010-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2010-1244", "id_number": "CaltechAUTHORS:20191016-100220993", "isbn": "978-1-60086-959-4", "book_title": "48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191016-100220993", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "collection": "CaltechAUTHORS", "other_numbering_system": { "items": [ { "id": "2010-1244", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT", "value": "GALCIT" } ] }, "doi": "10.2514/6.2010-1244", "primary_object": { "basename": "AIAA-2010-1244.pdf", "url": "https://authors.library.caltech.edu/records/bgh2d-qfy15/files/AIAA-2010-1244.pdf" }, "pub_year": "2010", "author_list": "Wagnild, Ross M.; Candler, Graham V.; et el." }, { "id": "https://authors.library.caltech.edu/records/g9gne-p1f93", "eprint_id": 50108, "eprint_status": "archive", "datestamp": "2023-08-19 01:18:45", "lastmod": "2023-10-17 22:31:11", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Swantek-A-B", "name": { "family": "Swantek", "given": "A. B." } }, { "id": "Shukla-R-K", "name": { "family": "Shukla", "given": "R. K." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "J. M." } } ] }, "title": "Effect of Loading Wave Profile on Hydrodynamic Void Collapse in Detonation Initiation", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2010 by University of Illinois at Urbana-Champaign. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.\n\nAIAA 2010-771.\n\nThe authors gratefully acknowledge Prof John Lambros for the generous loan of laboratory equipment and\nspace which made this study possible. We thank Matthew Parker for his initial experiments, Prof Jonathan\nFreund, Prof Carlos Pantano, and Prof Scott Stewart for useful discussions comparing experiments and\nsimulations, and Prof Greg Elliott for helpful input with PIV measurements. We also thank Dr Eric Johnsen\nand Prof Tim Colonius for sharing their numerical data. This work was supported in part by the US\nDepartment of Energy through the University of California under subcontract B523819.\n\nPublished - 385401.pdf
", "abstract": "We experimentally and numerically investigate void collapse as a mechanism for detonation initiation in porous energetic materials under a stress-wave loading condition, representative of accidental mechanical insult. In contrast to the step loading of a shock, a\nstress wave induces a ramp loading, where length scales of the wave may be comparable to\nthe void size. Using an inert and transparent polymer material, we decouple the reactive\nand material aspects of void collapse, and focus instead on the hydrodynamic process of\ninteractive void collapse. Diagnostic techniques include high speed shadowgraph movies\nof the collapsing voids and particle image velocimetry in the surrounding material. Two\ndimensional finite volume simulations compare the interaction of a single void undergoing\nramp and shock wave loading. Voids exhibit asymmetric collapse, with formation of a high\nspeed jet that originates from proximal wall of the void. Data obtained, including internal\nvolume histories and collapse times of current experiments and simulations, are reported\nand compared with shock-induced cavity collapse data from the literature.", "date": "2010-01", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "id_number": "CaltechAUTHORS:20140930-075215676", "isbn": "978-1-60086-959-4", "book_title": "48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140930-075215676", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Department of Energy (DOE)", "grant_number": "B523819" } ] }, "collection": "CaltechAUTHORS", "local_group": { "items": [ { "id": "GALCIT", "value": "GALCIT" } ] }, "doi": "10.2514/6.2010-771", "primary_object": { "basename": "385401.pdf", "url": "https://authors.library.caltech.edu/records/g9gne-p1f93/files/385401.pdf" }, "pub_year": "2010", "author_list": "Swantek, A. B.; Shukla, R. K.; et el." }, { "id": "https://authors.library.caltech.edu/records/myjcx-vwh87", "eprint_id": 99297, "eprint_status": "archive", "datestamp": "2023-08-19 01:20:26", "lastmod": "2023-10-18 18:12:55", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ferrante-Antonino", "name": { "family": "Ferrante", "given": "Antonino" }, "orcid": "0000-0002-5336-572X" }, { "id": "Matheou-Georgios", "name": { "family": "Matheou", "given": "Georgios" }, "orcid": "0000-0003-4024-4571" }, { "id": "Dimotakis-P-E", "name": { "family": "Dimotakis", "given": "Paul E." } } ] }, "title": "LES of an Inclined Jet into a Supersonic Turbulent Crossflow: Synthetic Inflow Conditions", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2010 by A. Ferrante. Published by the American Institute of Aeronautics and Astronautics, Inc. with permission.", "abstract": "The main flow features generated by the gas-dynamic interactions of an inclined jet with a supersonic crossflow, such as barrel shock, shear layer, and counter-rotating vortex pair, were numerically captured by large-eddy simulation with subgrid scale (LES-SGS) stretched vortex model (AIAA Paper 2009-1511). In that study, the transition and spatial development of the jet were found to be strongly dependent on the inflow conditions of the crossflow. This result indicates that correct turbulent inflow conditions are necessary to predict the main flow characteristics, dispersion and mixing, of a gaseous jet in a supersonic, turbulent crossflow. This work presents a methodology for the generation of realistic synthetic turbulent inflow conditions for LES of spatially developing, supersonic, turbulent wail-bounded flows. The methodology is applied to the study of a supersonic turbulent flow over a flat wall interacting with an inclined jet. The results are compared with available experimental data, and the main flow characteristics and dominant vortical structures generated by the jet/turbulent-boundary-layer interaction are described.", "date": "2010-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2010-1287", "id_number": "CaltechAUTHORS:20191016-101252717", "isbn": "978-1-60086-959-4", "book_title": "48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191016-101252717", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "collection": "CaltechAUTHORS", "other_numbering_system": { "items": [ { "id": "2010-1287", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT", "value": "GALCIT" } ] }, "doi": "10.2514/6.2010-1287", "pub_year": "2010", "author_list": "Ferrante, Antonino; Matheou, Georgios; et el." }, { "id": "https://authors.library.caltech.edu/records/8nsr4-fx472", "eprint_id": 50109, "eprint_status": "archive", "datestamp": "2023-08-19 01:18:51", "lastmod": "2023-10-17 22:31:14", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Sharma-M", "name": { "family": "Sharma", "given": "M." } }, { "id": "Swantek-A-B", "name": { "family": "Swantek", "given": "A. B." } }, { "id": "Flaherty-W", "name": { "family": "Flaherty", "given": "W." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "J. M." } }, { "id": "Glumac-N-G", "name": { "family": "Glumac", "given": "N. G." } } ] }, "title": "Expansion Tube Investigation of Shock Stand-Off Distances in High-Enthalpy CO_2 Flow Over Blunt Bodies", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2010 by Manu Sharma. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.\n\nAIAA 2010-1566.\n\nPublished - 385512.pdf
", "abstract": "The shock standoff distance in front of a blunt body is sensitive to the thermochemical\nstate of the free stream. Recently, experimental and numerical studies\nhave reported significantly different bow shock profiles in high-enthalpy carbon\ndioxide flows, a discrepancy that may result from non-equilibrium processes during\nflow acceleration in ground-based facilities. In this work, an expansion tube is used\nto create a Mach 5.7 carbon dioxide flow, matching the stagnation enthalpy and\nthe velocity of previous studies. Images of shock layers are obtained for spherical\ngeometries and a scaled model of the Mars Science Lander. Different sphere\ndiameters are used in order to access non-equilibrium and equilibrium stagnation\nline shock profiles predicted by theory. Mars Science Lander profiles at zero angle\nof attack are in good agreement with available data from the LENS X expansion\ntunnel facility, confirming results are facility-independent for the same type of flow\nacceleration, and indicating the flow velocity is a suitable first-order matching parameter\nfor comparative testing. Heat transfer measurements on the Mars Science\nLander are also presented for the three different angle of attacks, and the results\nare consistent with previous studies. Initial results from a proposed organo-metallic\nbased emission spectroscopy technique for bow shock layer interrogation are also\npresented.", "date": "2010-01", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "id_number": "CaltechAUTHORS:20140930-075835687", "isbn": "978-1-60086-959-4", "book_title": "48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140930-075835687", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2010-1566", "primary_object": { "basename": "385512.pdf", "url": "https://authors.library.caltech.edu/records/8nsr4-fx472/files/385512.pdf" }, "pub_year": "2010", "author_list": "Sharma, M.; Swantek, A. B.; et el." }, { "id": "https://authors.library.caltech.edu/records/0s7jg-v5917", "eprint_id": 24213, "eprint_status": "archive", "datestamp": "2023-08-19 01:08:51", "lastmod": "2023-10-23 20:23:34", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Karnesky-J", "name": { "family": "Karnesky", "given": "J." } }, { "id": "Damazo-J-S", "name": { "family": "Damazo", "given": "J." }, "orcid": "0000-0002-4155-7177" }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "J. E." }, "orcid": "0000-0003-3181-9310" }, { "id": "Rusinek-A", "name": { "family": "Rusinek", "given": "A." } } ] }, "title": "Plastic Response of Thin-Walled Tubes to Detonation", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2010 ASME. This research was sponsored by the Department of Homeland Security through the University of Rhode Island. DHSURI Center of Excellence for Explosives Detection, Mitigation and Response, Structural Response to Internal Explosions (URI Grant No. 12208-0001865, DHS Grant No. 2008-ST-061-ED0002), project officer Dr. Jimmie Oxley. Prof. Rusinek carried out the double shear testing of the tube material at the University Paul Verlaine of Metz.\n\nPublished - Karnesky2010p14334Proceedings_Of_The_Asme_Pressure_Vessels_And_Piping_Conference_2010_Vol_4.pdf
", "abstract": "Elastic and plastic deformation of tubes to internal detonations\nand the shock waves produced by their reflection were\ninvestigated. The study included experimental measurements\nas well as computational modeling. Tests with stoichiometric\nethylene-oxygen mixtures were performed at various initial pressures\nand strain was measured on thin-walled mild-steel tubes.\nThe range of initial pressures covered the span from entirely elastic\nto fully plastic deformation modes. A model for the pressure\nload on the tube wall was developed and tested against experimental\nmeasurements. This model was applied as a boundary\ncondition in both a single degree of freedom model of the tube\ncross section and a finite element model of the entire tube. Comparison\nof computational and experimental results showed reasonable\nagreement if both strain-rate and strain-hardening effects\nwere accounted for. A unique mode of periodic radial deformation\nwas discovered and explained through modeling as the result\nof flexural wave interference effects.", "date": "2010", "date_type": "published", "publisher": "American Society of Mechanical Engineers", "place_of_pub": "New York", "pagerange": "263-277", "id_number": "CaltechAUTHORS:20110627-091506026", "isbn": "978-0-7918-4923-1", "book_title": "Proceedings of the ASME Pressure Vessels and Piping Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110627-091506026", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Department of Homeland Security", "grant_number": "12208-0001865" }, { "agency": "Department of Homeland Security", "grant_number": "2008-ST-061-ED0002" } ] }, "collection": "CaltechAUTHORS", "local_group": { "items": [ { "id": "GALCIT", "value": "GALCIT" } ] }, "primary_object": { "basename": "Karnesky2010p14334Proceedings_Of_The_Asme_Pressure_Vessels_And_Piping_Conference_2010_Vol_4.pdf", "url": "https://authors.library.caltech.edu/records/0s7jg-v5917/files/Karnesky2010p14334Proceedings_Of_The_Asme_Pressure_Vessels_And_Piping_Conference_2010_Vol_4.pdf" }, "pub_year": "2010", "author_list": "Karnesky, J.; Damazo, J.; et el." }, { "id": "https://authors.library.caltech.edu/records/tg48d-w5w92", "eprint_id": 24408, "eprint_status": "archive", "datestamp": "2023-08-19 01:08:59", "lastmod": "2024-01-13 05:18:06", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "McKeon-B-J", "name": { "family": "McKeon", "given": "Beverley J." }, "orcid": "0000-0003-4220-1583" } ] }, "title": "Turbulent Channel Flow over Model \"Dynamic\" Roughness", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2010 Springer Science+Business Media B. V.\n\nThe author wishes to acknowledge Javier Jim\u00e9nez for generously permitting the use of the DNS code and for useful conversations and ideas, and the support of a CTR Summer Program fellowship during the summer of 2008.", "abstract": "Turbulent flow over a \"dynamically rough\" wall is modeled by considering time-dependent velocity perturbations in the streamwise and wall-normal directions imposed at the wall, a crude linearization. Analysis of the linearized Navier-Stokes operator is performed to select roughness parameters that are predicted to lead to a large disturbance amplification in the body of the flow. Direct numerical simulations of turbulent channel flow at Re_\u03c4 ~ 500 with three different roughness amplitudes, a^+, indicate that for a^+ = 10 the response of the flow approximates this predicted form, including the development of a significant span-wise velocity component. The turbulence characteristics, as a function of amplitude, are hypothesized to offer insight of relevance to the static roughness problem.", "date": "2010", "date_type": "published", "publisher": "Springer", "pagerange": "87-92", "id_number": "CaltechAUTHORS:20110713-114512764", "isbn": "978-90-481-9630-2", "book_title": "IUTAM Symposium on The Physics of Wall-Bounded Turbulent Flows on Rough Walls", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110713-114512764", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "CTR Summer Program fellowship" } ] }, "collection": "CaltechAUTHORS", "local_group": { "items": [ { "id": "GALCIT", "value": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Nickels-T-B", "name": { "family": "Nickels", "given": "T. B." } } ] }, "doi": "10.1007/978-90-481-9631-9_12", "pub_year": "2010", "author_list": "McKeon, Beverley J." }, { "id": "https://authors.library.caltech.edu/records/9rzkk-ck262", "eprint_id": 18757, "eprint_status": "archive", "datestamp": "2023-08-21 22:58:16", "lastmod": "2024-01-12 23:40:24", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Brown-J-L", "name": { "family": "Brown", "given": "J. L." } }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "G." }, "orcid": "0000-0002-2912-0001" } ] }, "title": "Shockwaves in converging geometries", "ispublished": "unpub", "full_text_status": "public", "keywords": "Converging shocks; Mach reflection; EOS", "note": "\u00a9 2009 American Institute of Physics. \n\nThe research support provided by the Caltech Center for the Predictive Modeling and Simulation of High-Energy Density Dynamic Response of Materials through the U.S. Department of Energy contract DE-FC52-08NA28613 is gratefully acknowledged.\n\nPublished - Brown2009p10019Aip_Conf_Proc.pdf
", "abstract": "Plate impact experiments are a powerful tool in equation of state (EOS) development, but are inherently limited by the range of impact velocities accessible to the gun. In an effort to dramatically increase the range of pressures which can be studied with available impact velocities, a new experimental technique is being developed. The possibility of using a confined converging target to focus Shockwaves and produce a large amplitude pressure pulse is examined. When the planar shock resulting from impact enters the converging target the impedance mismatch at the boundary of the confinement produces reflected Mach waves and the subsequent wave interactions produce a diffraction cycle resulting in increases in the shock strength with each cycle. Since this configuration is limited to relatively low impedance targets, a second technique is proposed in which the target is two concentric cylinders designed such that the inner cylinder will have a lower shock velocity than the much larger shock velocity in the outer cylinder. The resulting dispersion in the wave front creates converging shocks, which will interact and eventually result in a steady Mach configuration with an increase in pressure in the Mach disk. Numerical simulations indicate a significant increase in pressure for both methods and show promise for the proposed concepts.", "date": "2009-12-28", "date_type": "published", "publisher": "American Institute of Physics", "pagerange": "747-750", "id_number": "CaltechAUTHORS:20100621-150110109", "isbn": "978-0-7354-0732-9", "book_title": "Shock-induced spall in copper: The effects of anisotropy, temperature, defects and loading pulse", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100621-150110109", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Department of Energy (DOE) National Nuclear Security Administration", "grant_number": "DE-FC52-08NA28613" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1063/1.3295249", "primary_object": { "basename": "Brown2009p10019Aip_Conf_Proc.pdf", "url": "https://authors.library.caltech.edu/records/9rzkk-ck262/files/Brown2009p10019Aip_Conf_Proc.pdf" }, "pub_year": "2009", "author_list": "Brown, J. L. and Ravichandran, G." }, { "id": "https://authors.library.caltech.edu/records/1hemk-8hq81", "eprint_id": 72260, "eprint_status": "archive", "datestamp": "2023-08-19 00:43:56", "lastmod": "2023-10-23 20:33:39", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chang-Insu", "name": { "family": "Chang", "given": "Insu" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Exponential Stability Region Estimates for the State-Dependent Riccati Equation Controllers", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2009 IEEE. \n\nDate of Conference: 15-18 Dec. 2009. Date Added to IEEE Xplore: 29 January 2010. \n\nThis work was supported by the Air Force Office of Scientific Research (AFOSR). The authors thank Prof. J. Oliver at the Virtual Reality Application Center, Iowa State University for his support. The authors gratefully acknowledge stimulating discussions with Prof. J.-J. E. Slotine, Dr. W. Lohmiller, and A. A. Paranjape.\n\nPublished - 05400575.pdf
", "abstract": "We investigate the nonlinear exponential stability of the State-Dependent Riccati Equation (SDRE)-based control. The SDRE technique is a nonlinear control method, which has emerged since the mid 1990's and has been applied to a wide range of nonlinear control problems. Despite the systematic method of SDRE, it is difficult to prove stability because the general analytic solution to the SDRE is not known. Some notable prior work has shown local asymptotic stability of SDRE by using numerical and analytical methods. In this paper, we introduce a new strategy, based on contraction analysis, to estimate the exponential stability region for SDRE controlled systems. Examples demonstrate the superiority of the proposed method.", "date": "2009-12", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "1974-1979", "id_number": "CaltechAUTHORS:20161122-145958877", "isbn": "978-1-4244-3872-3", "book_title": "Joint 48h IEEE Conference on Decision and Control (CDC) held jointly with 2009 28th Chinese Control Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161122-145958877", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)" }, { "agency": "Iowa State University" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/CDC.2009.5400575", "primary_object": { "basename": "05400575.pdf", "url": "https://authors.library.caltech.edu/records/1hemk-8hq81/files/05400575.pdf" }, "pub_year": "2009", "author_list": "Chang, Insu and Chung, Soon-Jo" }, { "id": "https://authors.library.caltech.edu/records/937bw-2jg33", "eprint_id": 99148, "eprint_status": "archive", "datestamp": "2023-08-19 00:21:33", "lastmod": "2023-10-18 17:54:06", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Leyva-I-A", "name": { "family": "Leyva", "given": "Ivett A." } }, { "id": "Jewell-J-S", "name": { "family": "Jewell", "given": "Joseph S." }, "orcid": "0000-0002-4047-9998" }, { "id": "Laurence-S-J", "name": { "family": "Laurence", "given": "Stuart" } }, { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "Hans G." }, "orcid": "0000-0002-4903-8419" }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "Joseph E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "On the impact of injection schemes on transition in hypersonic boundary layers", "ispublished": "unpub", "full_text_status": "public", "note": "This material is declared a work of the U.S. Government and is not subject to copyright protection in the United States. \n\nThe authors would like to thank Bahram Valiferdowsi for helping with the design of the injection pieces and with the maintenance of the facility. Financial support for this work was provided in part by the Air Force Office of Scientific Research, USAF, under grant/contract number F49620-IHOUSE07E0000. The program manager is Dr. John Schmisseur to whom the authors are grateful for his continued support throughout this project.\n\nPublished - AIAA-2009-7204.pdf
", "abstract": "Three geometries are explored for injecting CO_2 into the boundary layer of a sharp five degree half-angle cone. The impact of the injection geometry, namely discrete injection holes or a porous conical section, on tripping the boundary layer is examined, both with and without injected flow. The experiments are conducted at Caltech's T5 reflected shock tunnel. Two different air free-stream conditions are explored. For the discrete-hole injectors, the diameter for the injection holes is 0.75 mm nominally and the length to diameter ratio is about 30. One injector has a single row of holes and the other has four rows. With the 4-row geometry fully turbulent heat transfer values are measured within four centimeters of the last injection row for both free-stream conditions. The 1-row injector results on a reduction of 50% in the transition Reynolds number. The porous injector does not move the transition Reynolds number upstream by itself with no injection flow.", "date": "2009-10-19", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2009-7204", "id_number": "CaltechAUTHORS:20191008-111635277", "isbn": "9781600869686", "book_title": "16th AIAA/DLR/DGLR International Space Planes and Hypersonic Systems and Technologies Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191008-111635277", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "F49620-IHOUSE07E0000" } ] }, "collection": "CaltechAUTHORS", "other_numbering_system": { "items": [ { "id": "2009-7204", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT", "value": "GALCIT" } ] }, "doi": "10.2514/6.2009-7204", "primary_object": { "basename": "AIAA-2009-7204.pdf", "url": "https://authors.library.caltech.edu/records/937bw-2jg33/files/AIAA-2009-7204.pdf" }, "pub_year": "2009", "author_list": "Leyva, Ivett A.; Jewell, Joseph S.; et el." }, { "id": "https://authors.library.caltech.edu/records/8zpg2-m1v36", "eprint_id": 72258, "eprint_status": "archive", "datestamp": "2023-08-19 00:14:35", "lastmod": "2023-10-23 20:33:33", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "\u00c7elik-K", "name": { "family": "\u00c7elik", "given": "Koray" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Clausman-M", "name": { "family": "Clausman", "given": "Matthew" } }, { "id": "Somani-A-K", "name": { "family": "Somani", "given": "Arun K." } } ] }, "title": "Monocular Vision SLAM for Indoor Aerial Vehicles", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2009 IEEE. \n\nDate of Conference: 10-15 Oct. 2009. Date Added to IEEE Xplore: 15 December 2009. \n\nThe research reported in this paper was in part supported by National Science Foundation (Grant ECCS-0428040), Information Infrastructure Institute (I3), Department of Aerospace Engineering and Virtual Reality Application Center at Iowa State University, and Air Force Office of Scientific Research.\n\nPublished - 05354050.pdf
", "abstract": "This paper presents a novel indoor navigation and ranging strategy by using a monocular camera. The proposed algorithms are integrated with simultaneous localization and mapping (SLAM) with a focus on indoor aerial vehicle applications. We experimentally validate the proposed algorithms by using a fully self-contained micro aerial vehicle (MAV) with on-board image processing and SLAM capabilities. The range measurement strategy is inspired by the key adaptive mechanisms for depth perception and pattern recognition found in humans and intelligent animals. The navigation strategy assumes an unknown, GPS-denied environment, which is representable via corner-like feature points and straight architectural lines. Experimental results show that the system is only limited by the capabilities of the camera and the availability of good corners.", "date": "2009-10", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "1566-1573", "id_number": "CaltechAUTHORS:20161122-144014712", "isbn": "978-1-4244-3803-7", "book_title": "IEEE/RSJ International Conference on Intelligent Robots and Systems, 2009", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161122-144014712", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "ECCS-0428040" }, { "agency": "Iowa State University" }, { "agency": "Air Force Office of Scientific Research (AFOSR)" } ] }, "collection": "CaltechAUTHORS", "local_group": { "items": [ { "id": "GALCIT", "value": "GALCIT" } ] }, "doi": "10.1109/IROS.2009.5354050", "primary_object": { "basename": "05354050.pdf", "url": "https://authors.library.caltech.edu/records/8zpg2-m1v36/files/05354050.pdf" }, "pub_year": "2009", "author_list": "\u00c7elik, Koray; Chung, Soon-Jo; et el." }, { "id": "https://authors.library.caltech.edu/records/me2pn-yaj68", "eprint_id": 99149, "eprint_status": "archive", "datestamp": "2023-08-20 02:32:44", "lastmod": "2023-10-18 17:54:09", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Muse-Joanthan-A", "name": { "family": "Muse", "given": "Jonathan A." } }, { "id": "Tchieu-A-A", "name": { "family": "Tchieu", "given": "Andrew A." } }, { "id": "Kutay-A-T", "name": { "family": "Kutay", "given": "Ali T." } }, { "id": "Chandramohan-R", "name": { "family": "Chandramohan", "given": "Rajeev" } }, { "id": "Calise-A-J", "name": { "family": "Calise", "given": "Anthony J." } }, { "id": "Leonard-A", "name": { "family": "Leonard", "given": "Anthony" } } ] }, "title": "Vortex Model Based Adaptive Flight Control Using Synthetic Jets", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2009 American Institute of Aeronautics and Astronautics. \n\nThis work has been supported by AFOSR. The authors would also like to Dr. Ari Glezer of the Mechanical Engineering Department at Georgia Tech, and the members of his team (Dan Brzozowski and John Culp) for their efforts in making this research possible.\n\nPublished - MuseAIAA2009.pdf
", "abstract": "A simple low-order model is derived for developing flight control laws for controlling the longitudinal dynamics of an aircraft using synthetic jet type actuators. Bi-directional changes in the pitching moment over a range of angles of attack are effected by controllable, nominally-symmetric trapped vorticity concentrations on both the suction and pressure surfaces near the trailing edge. Actuation is applied on both surfaces by hybrid actuators that are each comprised of a miniature obstruction integrated with a synthetic jet actuator to manipulate and regulate the vorticity concentrations. In previous work, a simple model was derived from a reduced order vortex model that includes one explicit nonlinear state for fluid variables and can be easily coupled to the rigid body dynamics of an aircraft. This paper further simplifies this model for control design. The control design is based on an output feedback adaptive control methodology that illustrates the effectiveness of using the model for achieving flight control at a higher bandwidth than achievable with typical static actuator assumptions. A unique feature of the control design is that the control variable is a pseudo-control based on regulating a control vortex strength. Wind tunnel experiments on a unique dynamics traverse verify that tracking performance is indeed better than control designs employing standard actuator modeling assumptions.", "date": "2009-08-10", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2009-5761", "id_number": "CaltechAUTHORS:20191008-111635395", "isbn": "9781600869785", "book_title": "AIAA Guidance, Navigation, and Control Conference 2009", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191008-111635395", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)" } ] }, "other_numbering_system": { "items": [ { "id": "2009-5761", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2009-5761", "primary_object": { "basename": "MuseAIAA2009.pdf", "url": "https://authors.library.caltech.edu/records/me2pn-yaj68/files/MuseAIAA2009.pdf" }, "pub_year": "2009", "author_list": "Muse, Jonathan A.; Tchieu, Andrew A.; et el." }, { "id": "https://authors.library.caltech.edu/records/r0js4-jrp37", "eprint_id": 72488, "eprint_status": "archive", "datestamp": "2023-08-20 02:27:43", "lastmod": "2023-10-23 22:39:29", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chang-Insu", "name": { "family": "Chang", "given": "Insu" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Bio-Inspired Adaptive Cooperative Control of Heterogeneous Robotic Networks", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2009 American Institute of Aeronautics and Astronautics. \n\nThis was supported by the Air Force Office of Scientific Research (AFOSR). The authors thank Prof. James Oliver at the Virtual Reality Application Center, Iowa State University for his support. The authors gratefully acknowledge stimulating discussions with Prof. Jean-Jacques E. Slotine at Massachusetts Institute of Technology.\n\nPublished - Chang_AIAA2009-5886.pdf
", "abstract": "We introduce a new adaptive cooperative control strategy for robotic networks comprised of heterogeneous members. The proposed feedback synchronization exploits an active parameter adaptation strategy as opposed to adaptive parameter estimation of adaptive control theory. Multiple heterogeneous robots or vehicles can coordinate their motions by parameter adaptation analogous to bio-genetic mutation and adaptation. In contrast with fixed gains used by consensus theory, both the tracking control and diffusive coupling gains are automatically computed based on the adaptation law, the synchronization errors, and the tracking errors of heterogeneous robots. The optimality of the proposed adaptive cooperative control is studied via inverse optimal control theory. The proposed adaptive\ncooperative control can be applied to any network structure. The stability proof, by using a relatively new nonlinear stability tool, contraction theory, shows globally asymptotically synchronized motion of a heterogeneous robotic network. This adaptive cooperative control can be widely applied to cooperative control of unmanned aerial vehicles (UAVs), formation flying spacecraft, and multi-robot systems. Results of the simulation show the effectiveness of the proposed adaptive cooperative control laws especially for a network comprised of heterogeneous members.", "date": "2009-08", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics (AIAA)", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2009-5886", "id_number": "CaltechAUTHORS:20161201-065326671", "isbn": "978-1-60086-978-5", "book_title": "AIAA Guidance, Navigation, and Control Conference 2009", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161201-065326671", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)" }, { "agency": "Iowa State University" } ] }, "other_numbering_system": { "items": [ { "id": "2009-5886", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2009-5886", "primary_object": { "basename": "Chang_AIAA2009-5886.pdf", "url": "https://authors.library.caltech.edu/records/r0js4-jrp37/files/Chang_AIAA2009-5886.pdf" }, "pub_year": "2009", "author_list": "Chang, Insu and Chung, Soon-Jo" }, { "id": "https://authors.library.caltech.edu/records/4ewjk-7b725", "eprint_id": 50110, "eprint_status": "archive", "datestamp": "2023-08-20 02:27:05", "lastmod": "2023-10-17 22:31:17", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Shukla-R-K", "name": { "family": "Shukla", "given": "R. K." } }, { "id": "Pantano-C", "name": { "family": "Pantano", "given": "C." } }, { "id": "Jackson-T-L", "name": { "family": "Jackson", "given": "T. L." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "J. M." } }, { "id": "Freund-J-B", "name": { "family": "Freund", "given": "J. B." } } ] }, "title": "Shock Induced Detonations in Composite Heterogeneous Energetic Materials", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2009 by the Authors. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.\n\nAIAA 2009-5503.\n\nThis work was supported by the US Department of Energy via the Center for Simulation of Advanced\nRockets at the University of Illinois at Urbana-Champaign and by the United States Air Force Office of\nScientific Research.\n\nPublished - 385513.pdf
", "abstract": "Solid energetic materials are used in a wide variety of applications, including solid rocket\nmotors, munitions, explosives for construction and demolition, automotive airbags, and pyrotechnic fasteners and actuators for space applications. An understanding of their potential for initiation and explosion is vital for their safe storage, handling, and transportation.\nBecause of the rich phenomenology associate with microstructural geometric features, such\npack as morphology, the presence of voids, and the type of binder, one-dimensional empirical models will be limited in predicting the shock sensitivity of energetic materials for a\nwide variety of insults. Therefore, the goal of our research is to develop a multidimensional\nshock-sensitivity model that accounts for microstructural geometric features. Here, we\nreport a novel shock capturing multi-phase flow solver, which combines the features of a\nlevel-set method and a time dependent mesh redistribution technique. Numerical simulations of multi-material inert shock problems and detonation initiation through localized\nthermal energy deposition are used to demonstrate the method.", "date": "2009-08", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "id_number": "CaltechAUTHORS:20140930-080257698", "isbn": "978-1-60086-972-3", "book_title": "45th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140930-080257698", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Department of Energy (DOE) Center for Simulation of Advanced Rockets" }, { "agency": "Air Force Office of Scientific Research (AFOSR)" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2009-5503", "primary_object": { "basename": "385513.pdf", "url": "https://authors.library.caltech.edu/records/4ewjk-7b725/files/385513.pdf" }, "pub_year": "2009", "author_list": "Shukla, R. K.; Pantano, C.; et el." }, { "id": "https://authors.library.caltech.edu/records/76g2v-cwm53", "eprint_id": 99150, "eprint_status": "archive", "datestamp": "2023-08-20 02:06:54", "lastmod": "2023-10-18 17:54:11", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Marineau-E-C", "name": { "family": "Marineau", "given": "Eric C." } }, { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "Hans G." }, "orcid": "0000-0002-4903-8419" } ] }, "title": "High-Enthalpy Nonequilibrium Nozzle Flow of Air: Experiments and Computations", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2009 American Institute of Aeronautics and Astronautics.", "abstract": "An investigation of the nozzle expansion of air from a reservoir at high specific enthalpy is presented. The objective is to test the chemical models assumed in nonequilibrium numerical computations and obtain a better understanding of the conditions at the nozzle exit as a function of the reservoir conditions. Static pressure measurements at the nozzle exit are performed in the T5 free-piston shock tunnel at the California Institute of Technology and compared with computations using DPLR CFD code which solves the chemically reactive Navier Stokes equations. Experiments are performed at four conditions with a range of stagnation pressures between 20 and 60 MPa and stagnation enthalpies between 10 and 17 MJ/kg. The measured static pressures are between 10% to 17% lower than those computed which seems to indicate that less recombination occurs in the experiment.", "date": "2009-06-22", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2009-4216", "id_number": "CaltechAUTHORS:20191008-111635513", "isbn": "9781600869716", "book_title": "39th AIAA Fluid Dynamics Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191008-111635513", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2009-4216", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2009-4216", "pub_year": "2009", "author_list": "Marineau, Eric C. and Hornung, Hans G." }, { "id": "https://authors.library.caltech.edu/records/x4gyr-57h75", "eprint_id": 18075, "eprint_status": "archive", "datestamp": "2023-08-20 01:51:16", "lastmod": "2023-10-20 15:33:53", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Sanderson-S-R", "name": { "family": "Sanderson", "given": "Simon R." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "Joanna M." } }, { "id": "Liang-Zhe", "name": { "family": "Liang", "given": "Zhe" } }, { "id": "Pintgen-F", "name": { "family": "Pintgen", "given": "Florian" } }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "Joseph E." }, "orcid": "0000-0003-3181-9310" }, { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "Hans G." }, "orcid": "0000-0002-4903-8419" } ] }, "title": "Reactant Jetting in Unstable Detonation", "ispublished": "unpub", "full_text_status": "public", "note": "Manuscript prepared in honor of Prof. Hornung's 75th birthday.\n\nThe five junior authors wish to express their gratitude to Prof. Hornung for his enthusiastic guidance\nand friendship over a period of many years. The citations referenced in this paper clearly articulate the\npowerful influence that Hans' prior studies have exerted on the direction of the current investigation. This\nwork could never have begun without his leadership of the GALCIT community and his support for our\nprivileged membership of it. We happily dedicate this manuscript to the celebration of his 75th birthday.\n\nAccepted Version - DetJet.pdf
", "abstract": "We note the common existence of a supersonic jet structure locally embedded within a surrounding transonic flow field in the hitherto unrelated phenomena of unstable gaseous\ndetonation and hypervelocity blunt body shock wave interaction. Extending prior results that demonstrate the consequences of reduced endothermic reaction rate for the supersonic jet fluid in the blunt body case, we provide an explanation for observations of locally reduced OH PLIF signal in images of the keystone reaction zone structure of weakly unstable detonations. Modeling these flow features as exothermically reacting jets with similarly reduced reaction rates, we demonstrate a mechanism for jetting of bulk pockets of unreacted fluid with potentially differing kinetic pathways into the region behind the primary detonation front of strongly unstable mixtures. We examine the impact of mono-atomic and diatomic diluents on transverse structure. The results yield insight into the mechanisms of transition and characteristic features of both weakly and strongly unstable mixtures.", "date": "2009-06", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "pagerange": "Art. No. -2009-4325", "id_number": "CaltechAUTHORS:20100429-102004678", "isbn": "1-56347-975-3", "book_title": "39th AIAA Fluid Mechanics Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100429-102004678", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2009-4325", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2009-4325", "primary_object": { "basename": "DetJet.pdf", "url": "https://authors.library.caltech.edu/records/x4gyr-57h75/files/DetJet.pdf" }, "pub_year": "2009", "author_list": "Sanderson, Simon R.; Austin, Joanna M.; et el." }, { "id": "https://authors.library.caltech.edu/records/q4jy0-7ag21", "eprint_id": 50111, "eprint_status": "archive", "datestamp": "2023-08-20 01:53:54", "lastmod": "2023-10-17 22:31:20", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Sharma-M", "name": { "family": "Sharma", "given": "M." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "J. M." } }, { "id": "Glumac-N-G", "name": { "family": "Glumac", "given": "N. G." } }, { "id": "Massa-L", "name": { "family": "Massa", "given": "L." } } ] }, "title": "Spectroscopic Measurements in the Shock Relaxation Region of a Hypervelocity Mach Reflection", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2009 by Manu Sharma. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.\n\nThis research was funded in part through AFOSR/MURI Grant FA9550-04-1-0425 with Dr. John Schmisseur\nas Technical Monitor.\n\nAIAA 2009-4218.\n\nPublished - 385515.pdf
", "abstract": "We examine the spatial temperature profile in the non-equilibrium relaxation region\nbehind a stationary shock wave. The normal shock wave is established through a Mach\nreflection configuration from an opposing wedge arrangement for a hypervelocity air Mach\n7.42 freestream. Schlieren images confirm that the shock configuration is steady and the\nlocation is repeatable. Emission spectroscopy is used to identify dissociated species and to\nobtain vibrational temperature measurements using the NO and OH A-X band sequences.\nTemperature measurements are presented at selected locations behind the normal shock.\nLIFBASE is used as the simulation spectrum software for OH temperature-fitting, however the need to access higher vibrational and rotational levels for NO leads to the use of\nan in-house developed algorithm. For NO, results demonstrate the contribution of higher\nvibrational and rotational levels to the spectra at the conditions of this study. Very good\nagreement is achieved between the experimentally measured NO vibrational temperatures\nand calculations performed using a state-resolved, one-dimensional forced harmonic oscillator thermochemical model.", "date": "2009-06", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "id_number": "CaltechAUTHORS:20140930-080858431", "isbn": "978-1-60086-971-6", "book_title": "39th AIAA Fluid Dynamics Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140930-080858431", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR) Multidisciplinary University Research Initiative (MURI)", "grant_number": "FA9550-04-1-0425" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2009-4218", "primary_object": { "basename": "385515.pdf", "url": "https://authors.library.caltech.edu/records/q4jy0-7ag21/files/385515.pdf" }, "pub_year": "2009", "author_list": "Sharma, M.; Austin, J. M.; et el." }, { "id": "https://authors.library.caltech.edu/records/ergwp-mxw34", "eprint_id": 18135, "eprint_status": "archive", "datestamp": "2023-08-20 01:24:37", "lastmod": "2023-10-20 15:47:14", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "H. G." }, "orcid": "0000-0002-4903-8419" } ] }, "title": "Relaxation effects in hypervelocity flow: selected contributions from the T5 Lab", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2007 Springer.\nThe work described in sections 2, 3, 5, and 6 was supported by the United States Air Force Office of Scientific Research.", "abstract": "Experimental access to flows in the total enthalpy range from 5 to 20 MJ/kg was greatly increased by Stalker's [1] introduction of the free-piston shock tunnel in the 1960's. Since then, experiments conducted in the later T series of these (T3 in Canberra, T4 in Queensland, T5 at Caltech) and the larger machines (HEG in G\u00f6ttingen, HIEST in Japan) have changed the landscape of gasdynamics in this range enormously. Specifically, a number of previously unknown phenomena, some showing dramatic effects, were discovered by such experiments. The scope of this paper is much too constraining to do justice to the whole body of contributions of these research groups. Accordingly I will restrict it to a selection from those more familiar to me and that have come from the T5 laboratory. Much of the work in the total enthalpy range of the free-piston shock tunnels is concerned with the main enemy of this regime: heat flux.", "date": "2009-04-01", "date_type": "published", "publisher": "Springer", "pagerange": "3-10", "id_number": "CaltechAUTHORS:20100505-113815701", "isbn": "9783540851677", "book_title": "Shock Waves", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100505-113815701", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1007/978-3-540-85168-4_1", "pub_year": "2009", "author_list": "Hornung, H. G." }, { "id": "https://authors.library.caltech.edu/records/ga8c4-ggq46", "eprint_id": 73045, "eprint_status": "archive", "datestamp": "2023-08-20 01:23:00", "lastmod": "2023-10-24 14:59:28", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Stone-J-R", "name": { "family": "Stoner", "given": "Jeremiah R." } }, { "id": "Dorothy-M-R", "name": { "family": "Dorothy", "given": "Michael R." } } ] }, "title": "Neurobiologically Inspired Control of Engineered Flapping Flight", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2009 American Institute of Aeronautics and Astronautics.\n\nThis project was supported by the Air Force office of Scientific Research (AFOSR) under the Young Investigator Award Program (YIP) (contract monitor: Dr. Willard Larkin). This paper benefited from discussion with Profs. Jean-Jacques Slotine at MIT, Prof. Kenneth Breuer at Brown University, and Dr. Gregg Abate at the Air Force Research Lab. The first author appreciate Prof. Partha Sarka at Iowa State University for allowing him to use the wind tunnel facility in the Wind Simulation and Testing Laboratory. \n\nThe authors gratefully acknowlege contributions from the following students at Iowa State University: Anid Monsur, Antonella Albuja, Brad Smith, Christopher Massina, Keegan Gartner, Matt Hawkins, Merritt Tennison, and Ryan Paul.\n\nPublished - FlappingFlightInfoTech09.pdf
", "abstract": "This article presents a new control approach for engineered \nflapping flight with many interacting degrees of freedom. This paper explores the applications of neurobiologically\ninspired control systems in the form of Central Pattern Generators (CPG) to generate wing trajectories for potential flapping flight MAVs. We present a rigorous mathematical and control theoretic framework to design complex three dimensional motions of flapping wings. Most \nflapping flight demonstrators are mechanically limited in generating the wing trajectories. Because CPGs lend themselves to more biological examples of flight, a novel\nrobotic model has been developed to emulate the flight of bats. This model has shoulder and leg joints totaling 10 degrees of freedom for control of wing properties. Results of wind tunnel experiments and numerical simulation of CPG-based flight control validate the effectiveness of the proposed neurobiologically inspired control approach.", "date": "2009-04", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics (AIAA)", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2009-1929", "id_number": "CaltechAUTHORS:20161221-071846444", "isbn": "978-1-60086-979-2", "book_title": "AIAA Infotech@Aerospace Conference 2009", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161221-071846444", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)" } ] }, "other_numbering_system": { "items": [ { "id": "2009-1929", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2009-1929", "primary_object": { "basename": "FlappingFlightInfoTech09.pdf", "url": "https://authors.library.caltech.edu/records/ga8c4-ggq46/files/FlappingFlightInfoTech09.pdf" }, "pub_year": "2009", "author_list": "Chung, Soon-Jo; Stoner, Jeremiah R.; et el." }, { "id": "https://authors.library.caltech.edu/records/0sd75-eeg05", "eprint_id": 72407, "eprint_status": "archive", "datestamp": "2023-08-20 01:22:55", "lastmod": "2023-10-23 22:31:20", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "\u00c7elik-K", "name": { "family": "\u00c7elik", "given": "Koray" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Clausman-M", "name": { "family": "Clausman", "given": "Matthew" } }, { "id": "Somani-A-K", "name": { "family": "Somani", "given": "Arun" } } ] }, "title": "Biologically Inspired Monocular Vision Based Navigation and Mapping in GPS-Denied Environments", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2009 American Institute of Aeronautics and Astronautics.\n\nPublished - AIAA-2009-1962CelikChungSomani.pdf
", "abstract": "This paper presents an in-depth theoretical study of bio-vision inspired feature extraction and depth perception method integrated with vision-based simultaneous localization and mapping (SLAM). We incorporate the key functions of developed visual cortex in several advanced species, including humans, for depth perception and pattern recognition. Our navigation strategy assumes GPS-denied manmade environment consisting of orthogonal walls, corridors and doors. By exploiting the architectural features of the indoors, we introduce a method for gathering useful landmarks from a monocular camera for SLAM\nuse, with absolute range information without using active ranging sensors. Experimental results show that the system is only limited by the capabilities of the camera and the\navailability of good corners. The proposed methods are experimentally validated by our self-contained MAV inside a conventional building.", "date": "2009-04", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "pagerange": "Art. No.-2009", "id_number": "CaltechAUTHORS:20161129-121035179", "isbn": "978-1-60086-979-2", "book_title": "AIAA Infotech@Aerospace Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161129-121035179", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2009-1962", "primary_object": { "basename": "AIAA-2009-1962CelikChungSomani.pdf", "url": "https://authors.library.caltech.edu/records/0sd75-eeg05/files/AIAA-2009-1962CelikChungSomani.pdf" }, "pub_year": "2009", "author_list": "\u00c7elik, Koray; Chung, Soon-Jo; et el." }, { "id": "https://authors.library.caltech.edu/records/1d23h-zbk84", "eprint_id": 100786, "eprint_status": "archive", "datestamp": "2023-08-20 00:38:36", "lastmod": "2023-10-18 21:51:58", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Marineau-E-C", "name": { "family": "Marineau", "given": "Eric C." } }, { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "Hans G." }, "orcid": "0000-0002-4903-8419" } ] }, "title": "Modeling and Calibration of Fast-Response Coaxial Heat Flux Gages", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2009 by the American Institute of Aeronautics and Astronautics, Inc. \n\nPublished online: 15 Jun 2012.", "abstract": "This research focuses on the modeling and calibration of fast response coaxial heat flux gages. Simulations of the heat conduction inside the gage using Gasp solver show, that the response is sensitive to geometry of the junction which sits on epoxy. The epoxy acts as an insulator creating a local overheating that increases with the junction aspect ratio and the step height between the inner and outer electrodes and decreases when epoxy is present next to the step. The increase of the overheating with the junction aspect ratio is due to the thermal insulation of the epoxy layer located under the junction used to electrically insulate the two electrodes of the thermocouple. When the junction protrudes significantly above the surface (about 10 microns), the heat transfer is enhanced from the larger surface area whereas, the lateral conduction around the epoxy layer decreases, which further contributes to the junction overheating. To assess those effects, a calibration method using a reflected shock in argon is developed and experiments are performed in the T5 free-piston shock tunnel which is used as a shock tube by replacing the nozzle throat insert with a closed end-wall insert. Five gages are simultaneously calibrated at a high heat flux for 30 microseconds. For microsecond time scales, it is found that the effective value of the thermal product, \u221apck, is approximately 30% lower than the average of chromel and constantan. The standard deviation of 10% among the five gages indicates that the gage-to-gage variation of the junction geometry is relatively small as the temperature is greatly sensitive to the geometry on microsecond time scales.", "date": "2009-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2009-737", "id_number": "CaltechAUTHORS:20200117-095543698", "isbn": "978-1-60086-973-0", "book_title": "47th AIAA Aerospace Sciences Meeting including The New Horizons Forum and Aerospace Exposition", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200117-095543698", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2009-737", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2009-737", "pub_year": "2009", "author_list": "Marineau, Eric C. and Hornung, Hans G." }, { "id": "https://authors.library.caltech.edu/records/jqj04-yyd78", "eprint_id": 100781, "eprint_status": "archive", "datestamp": "2023-08-20 00:38:24", "lastmod": "2023-10-18 21:51:45", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ferrante-Antonino", "name": { "family": "Ferrante", "given": "Antonino" }, "orcid": "0000-0002-5336-572X" }, { "id": "Pantano-Carlos", "name": { "family": "Pantano", "given": "Carlos" }, "orcid": "0000-0003-3971-2278" }, { "id": "Matheou-Georgios", "name": { "family": "Matheou", "given": "George" }, "orcid": "0000-0003-4024-4571" }, { "id": "Dimotakis-P-E", "name": { "family": "Dimotakis", "given": "Paul E." } } ] }, "title": "On the Effects of the Upstream Conditions on the Transition of an Inclined Jet into a Supersonic Cross-Flow", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2009 by the American Institute of Aeronautics and Astronautics, Inc. \n\nPublished online: 15 Jun 2012.", "abstract": "The objective of this work is to explore and assess the effects of upstream conditions on the transition of an inclined jet into a supersonic cross-flow. The flow studied matches the experimental conditions of a sonic helium inclined-jet into a supersonic air cross-flow at Mach 3.6 by Maddalena, Campioli & Schetz (2006). We have performed large-eddy simulation with sub-grid scale (LES-SGS) stretched vortex model of turbulent and scalar transport developed by Pullin and co-workers. We have adopted a hybrid numerical approach with low numerical dissipation that uses tuned centered finite differences (TCD) in smooth flow regions and weighted essentially non-oscillatory (WENO) scheme around discontinuities and ghost-fluid boundaries. The LES results show that the main flow features generated by the gas-dynamics interaction of the jet with the cross-flow, such as barrel shock, Mach disk, shear layer, and counter-rotating vortex pair, are numerically captured. Comparison of the LES results with the experiments are discussed. The transition and spatial development of the helium jet are strongly dependent on the inflow conditions of the cross-flow. Thus, turbulent inflow conditions are necessary for the prediction of dispersion and mixing of a gaseous jet in a supersonic, turbulent cross-flow.", "date": "2009-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2009-1511", "id_number": "CaltechAUTHORS:20200117-082933028", "isbn": "978-1-60086-973-0", "book_title": "47th AIAA Aerospace Sciences Meeting including The New Horizons Forum and Aerospace Exposition", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200117-082933028", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2009-1511", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2009-1511", "pub_year": "2009", "author_list": "Ferrante, Antonino; Pantano, Carlos; et el." }, { "id": "https://authors.library.caltech.edu/records/g9qrp-agv11", "eprint_id": 100779, "eprint_status": "archive", "datestamp": "2023-08-20 00:38:18", "lastmod": "2023-10-18 21:51:40", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Leyva-I-A", "name": { "family": "Leyva", "given": "Ivett A." } }, { "id": "Laurence-S-J", "name": { "family": "Laurence", "given": "Stuart" } }, { "id": "Beierholm-A-W-K", "name": { "family": "Beierholm", "given": "Amy War-Kei" } }, { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "Hans G." }, "orcid": "0000-0002-4903-8419" }, { "id": "Wagnild-R-M", "name": { "family": "Wagnild", "given": "Ross" } }, { "id": "Candler-G-V", "name": { "family": "Candler", "given": "Graham" } } ] }, "title": "Transition Delay in Hypervelocity Boundary Layers by Means of CO\u2082/Acoustic Instability Interactions", "ispublished": "unpub", "full_text_status": "public", "note": "This material is declared a work of the U.S. Government and is not subject to copyright protection in the United States. \n\nPublished online: 15 Jun 2012.", "abstract": "A novel method to delay transition in hypervelocity flows over slender bodies by injecting CO\u2082 into the boundary layer of interest is investigated. The results presented here consist of both experimental and computational data. The experimental data was obtained at Caltech's T5 reflected shock tunnel, while the computational data was obtained at the University of Minnesota. The experimental model was a 5 degree sharp cone, chosen because of its relevance to axisymmetric hypersonic vehicle designs and the wealth of experimental and numerical data available for this geometry. The model was instrumented with thermocouples, providing heat transfer measurements from which transition locations were determined and the efficacy of adding CO\u2082 in delaying transition was gauged. For CO\u2082/N\u2082 freestream blends without injection, the transition Reynolds number more than doubled for mixtures with 40% CO\u2082 mole fraction compared to the case of 100% N\u2082. For the cases with injection, shadowgraph visualizations were obtained, allowing verification of the injection timing. The computations provide encouraging results that for the injection schemes proposed CO\u2082 is reaching high enough temperatures to excite vibrational modes and thus delay transition.", "date": "2009-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2009-1287", "id_number": "CaltechAUTHORS:20200117-080200964", "isbn": "978-1-60086-973-0", "book_title": "47th AIAA Aerospace Sciences Meeting including The New Horizons Forum and Aerospace Exposition", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200117-080200964", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2009-1287", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2009-1287", "pub_year": "2009", "author_list": "Leyva, Ivett A.; Laurence, Stuart; et el." }, { "id": "https://authors.library.caltech.edu/records/p9jwk-hap81", "eprint_id": 100782, "eprint_status": "archive", "datestamp": "2023-08-20 00:38:28", "lastmod": "2023-10-18 21:51:48", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Tanaki-Kohsuke", "name": { "family": "Tanaki", "given": "Kohsuke" } }, { "id": "Inaba-Kazuaki", "name": { "family": "Inaba", "given": "Kazuaki" } }, { "id": "Yamamoto-Makoto", "name": { "family": "Yamamoto", "given": "Makoto" } } ] }, "title": "Numerical Investigation on Transition of Shock Induced Boundary Layer", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2009 by the American Institute of Aeronautics and Astronautics, Inc. \n\nPublished online: 15 Jun 2012.", "abstract": "The purpose or this paper is to examine the application or empirical models or boundary layer transition to the situation of shock wave propagation. Two-dimensional numerical simulations of shock wave propagation and shock-induced boundary layer motion were performed with the turbulent intermittency transport model of Menter et al (2004). The Launder-Sharma low-Reynolds k-\u03f5 model was used for the turbulence model and the boundary layer profiles were compared against the theoretical laminar profiles and the empirical turbulent profiles. The predicted transition Reynolds number in the present study was in good agreement with the shock tube experimental data.", "date": "2009-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2009-1529", "id_number": "CaltechAUTHORS:20200117-085601492", "isbn": "978-1-60086-973-0", "book_title": "47th AIAA Aerospace Sciences Meeting including The New Horizons Forum and Aerospace Exposition", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200117-085601492", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2009-1529", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2009-1529", "pub_year": "2009", "author_list": "Tanaki, Kohsuke; Inaba, Kazuaki; et el." }, { "id": "https://authors.library.caltech.edu/records/frk3s-5m195", "eprint_id": 100785, "eprint_status": "archive", "datestamp": "2023-08-20 00:38:33", "lastmod": "2023-10-18 21:51:55", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Nango-Ayaka", "name": { "family": "Nango", "given": "Ayaka" } }, { "id": "Inaba-Kazuaki", "name": { "family": "Inaba", "given": "Kazuaki" } }, { "id": "Kojima-Takayuki", "name": { "family": "Kojima", "given": "Takayuki" } }, { "id": "Yamamoto-Makoto", "name": { "family": "Yamamoto", "given": "Makoto" } } ] }, "title": "Numerical Study on Single-Stage Axial Turbine with Pulse Detonation Combustor", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2009 by the American Institute of Aeronautics and Astronautics, Inc. \n\nPublished online: 15 Jun 2012.", "abstract": "Two-dimensional numerical simulations are conducted for a single-stage axial-turbine system with the inlet gas flow provided by a pulse detonation combustor. The objectives of this study are to compute the turbine work output as a function of rotor speed and gain insights into the significant gap between theoretical predictions and experimental results. The turbine work output is evaluated by two approaches. One is an energy balance evaluation method using average stagnation enthalpy at the stage inlet and outlet, and the other is a mechanical method of integrating the force acting on the rotor blade surface. From the results of both approaches, it is confirmed that the turbine work increases with increasing rotor speed up to 150% from the design point. Multi-cycle operation is also conducted at the design point for an initial pressure of 0.15 MPa and turbine adiabatic efficiency is observed to be reduced 5% after the second cycle.", "date": "2009-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2009-294", "id_number": "CaltechAUTHORS:20200117-094341473", "isbn": "978-1-60086-973-0", "book_title": "47th AIAA Aerospace Sciences Meeting including The New Horizons Forum and Aerospace Exposition", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200117-094341473", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2009-294", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2009-294", "pub_year": "2009", "author_list": "Nango, Ayaka; Inaba, Kazuaki; et el." }, { "id": "https://authors.library.caltech.edu/records/ejmnq-f2147", "eprint_id": 50128, "eprint_status": "archive", "datestamp": "2023-08-20 00:27:42", "lastmod": "2023-10-17 22:32:20", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Sharma-M", "name": { "family": "Sharma", "given": "M." } }, { "id": "Massa-L", "name": { "family": "Massa", "given": "L." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "J. M." } } ] }, "title": "Triple point shear layers in hypervelocity flow", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2009 Springer-Verlag Berlin Heidelberg.\n\nThis work was supported in part by the Air Force Office of Scientific Research,\nwith Dr. John Schmisscur as Technical Monitor.", "abstract": "Thermochemical processes such as dissociation and vibrational excitation can have a substantial impact on the gas dynamics of planetary entry. A critical question that confronts vehicle designers is the role of such molecular effects on transition and turbulence. In high stagnation enthalpy flows, thermochemical processes have been observed to affect transition to turbulence in boundary layers through modifications to the mean flow profile as well as to flow stability [1-3].", "date": "2009", "date_type": "published", "publisher": "Springer", "place_of_pub": "Berlin", "pagerange": "725-730", "id_number": "CaltechAUTHORS:20140930-150440935", "isbn": "978-3-540-85167-7", "book_title": "26th International Symposium on Shock Waves", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140930-150440935", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Hannemann-K", "name": { "family": "Hannemann", "given": "Klaus" } }, { "id": "Seiler-F", "name": { "family": "Seiler", "given": "Friedrich" } } ] }, "doi": "10.1007/978-3-540-85168-4_117", "pub_year": "2009", "author_list": "Sharma, M.; Massa, L.; et el." }, { "id": "https://authors.library.caltech.edu/records/mkk50-yxt06", "eprint_id": 18174, "eprint_status": "archive", "datestamp": "2023-08-20 00:18:12", "lastmod": "2024-01-12 23:39:06", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Laurence-S-J", "name": { "family": "Laurence", "given": "S. J." } }, { "id": "Deiterding-R", "name": { "family": "Deiterding", "given": "R." } }, { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "H. G." }, "orcid": "0000-0002-4903-8419" } ] }, "title": "Tandem spheres in hypersonic flow", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2009 Springer.", "abstract": "The problem of determining the forces acting on a secondary body when it is travelling at some point within the shocked region created by a hypersonic primary body is of interest in such situations as store or stage separation, re-entry of multiple vehicles, and atmospheric meteoroid fragmentation. The current work is concerned with a special case of this problem, namely that in which both bodies are spheres and are stationary with respect to one another. We first present an approximate analytical model of the problem; subsequently, numerical simulations are described and results are compared with those from the analytical model. Finally, results are presented from a series of experiments in the T5 hypervelocity shock tunnel in which a newly-developed force-measurement technique was employed.", "date": "2009", "date_type": "published", "publisher": "Springer", "pagerange": "713-718", "id_number": "CaltechAUTHORS:20100507-082816080", "isbn": "9783540851677", "book_title": "Shock Waves", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100507-082816080", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1007/978-3-540-85168-4_115", "pub_year": "2009", "author_list": "Laurence, S. J.; Deiterding, R.; et el." }, { "id": "https://authors.library.caltech.edu/records/ah8ft-e5v08", "eprint_id": 18176, "eprint_status": "archive", "datestamp": "2023-08-20 00:18:27", "lastmod": "2024-01-12 23:39:10", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Liang-Zhe", "name": { "family": "Liang", "given": "Z." } }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "J. E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "Structural response to detonation loading in 90-degree bend", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2009 Springer.", "abstract": "The structural response due to detonation propagation through a 90-degree bend in a circular tube was experimentally examined. Hoop strain measurements were obtained at key locations along the tube to measure elastic deformation. Dynamic pressure signals at the same locations were also recorded to track the detonation wave and record the peak pressure. Of particular interest are the effects of the bend on the magnitude of the pressure and strain in the material when compared to the straight tubes. These geometrical effects are due to the excitation of multiple modes: a short period detonation driven mode and longer period bending modes within the structure not seen in the straight tubes. The excitation of these bending modes serves to increase the maximum strain observed, which translates to greater hazards for industrial piping systems.", "date": "2009", "date_type": "published", "publisher": "Springer", "pagerange": "383-388", "id_number": "CaltechAUTHORS:20100507-084110753", "isbn": "9783540851677", "book_title": "Shock Waves", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100507-084110753", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1007/978-3-540-85168-4_61", "pub_year": "2009", "author_list": "Liang, Z. and Shepherd, J. E." }, { "id": "https://authors.library.caltech.edu/records/spmdk-tb306", "eprint_id": 18175, "eprint_status": "archive", "datestamp": "2023-08-20 00:18:20", "lastmod": "2024-01-12 23:39:08", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Mouton-C-A", "name": { "family": "Mouton", "given": "C. A." } }, { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "H. G." }, "orcid": "0000-0002-4903-8419" } ] }, "title": "Experimental investigation of tripping between regular and Mach reflection in the dual-solution domain", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2009 Springer.\nThis work was funded by the Air Force Office of Scientific Research, under the supervision of Dr. John Schmisseur.", "abstract": "Experiments were conducted in the Mach 4.0 Ludwieg tube facility at the California Institute of Technology. First, the hysteresis phenomenon, first proposed by [1] is explored. Second, tripping from regular reflection to Mach reflection by depositing laser energy onto one of the wedges is considered. These experimental results are compared with numerical computations and theoretical estimates.", "date": "2009", "date_type": "published", "publisher": "Springer", "pagerange": "1413-1418", "id_number": "CaltechAUTHORS:20100507-083350063", "isbn": "9783540851806", "book_title": "Shock Waves", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100507-083350063", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1007/978-3-540-85181-3_100", "pub_year": "2009", "author_list": "Mouton, C. A. and Hornung, H. G." }, { "id": "https://authors.library.caltech.edu/records/qt1y3-x3m43", "eprint_id": 98525, "eprint_status": "archive", "datestamp": "2023-08-22 12:46:23", "lastmod": "2024-01-14 21:56:08", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lombardini-M", "name": { "family": "Lombardini", "given": "Manuel" } }, { "id": "Deiterding-R", "name": { "family": "Deiterding", "given": "Ralf" } }, { "id": "Pullin-D-I", "name": { "family": "Pullin", "given": "D. I." } } ] }, "title": "Large Eddy Simulations of the Richtmyer\u2013Meshkov Instability in a Converging Geometry", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Large-eddy simulations (LES) with strong shocks; Richtmyer-Meshkov instability (RMI); Compressible turbulent mixing; Adaptive mesh refinement (AMR)", "note": "\u00a9 Springer-Verlag Berlin Heidelberg 2008. \n\nThe authors would like to acknowledge the helpful conversations with D.J. Hill. This work is supported by the ASC program of the Department of Energy under subcontract no. B341492 of DoE contract W-7405-ENG-48.", "abstract": "This work presents on-going research on large-eddy simulations of shock-generated mixing in Richtmyer-Meshkov flow in converging geometries. A hybrid numerical method is used on each subgrid of the mesh hierarchy within the AMROC (adaptive mesh refinement object oriented C++) framework: it is a shock capturing method but reverts to a centered scheme with low numerical viscosity in regions of smoother flow. The stretched-vortex subgrid-scale model allows for the capturing of the small-scale mixing process between the two fluids. Results presented focus on the evolution of the mixing layer and its internal statistics including various spectra and p.d.f.s of mixed molar and mass fractions. A detailed quantitative analysis has also been conducted including space-time histories of instantaneous cylindrical shell-averages of diverse quantities, taken concentrically to the main shocks. Comparisons are made with the planar Richtmyer-Meshkov instability with reshock studied by Vetter and Sturtevant (1995) [1] and Hill et al. (2006).", "date": "2008-08-20", "date_type": "published", "publisher": "Springer Netherlands", "place_of_pub": "Dordrecht", "pagerange": "283-294", "id_number": "CaltechAUTHORS:20190909-133031443", "isbn": "9781402085772", "book_title": "Quality and Reliability of Large-Eddy Simulations", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190909-133031443", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Department of Energy (DOE)", "grant_number": "W-7405-ENG-48" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Meyers-J", "name": { "family": "Meyers", "given": "Johan" } }, { "id": "Geurtz-B-J", "name": { "family": "Geurts", "given": "Bernard J." } }, { "id": "Sagaut-P", "name": { "family": "Sagaut", "given": "Pierre" } } ] }, "doi": "10.1007/978-1-4020-8578-9_23", "pub_year": "2008", "author_list": "Lombardini, Manuel; Deiterding, Ralf; et el." }, { "id": "https://authors.library.caltech.edu/records/vr2e0-bqz13", "eprint_id": 73072, "eprint_status": "archive", "datestamp": "2023-08-19 23:23:39", "lastmod": "2023-10-24 15:00:50", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Berg-Taylor-K", "name": { "family": "Berg-Taylor", "given": "Kito" } }, { "id": "Seo-Keehong", "name": { "family": "Seo", "given": "Keehong" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Sensor Based Path Planning in Highly Constrained Environments for Agile Autonomous Vehicles", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2008 American Institute of Aeronautics and Astronautics. \n\nThe research reported in this article was in part supported by the Air Force O\u00b1ce of Scientific Research (AFOSR) and the Information Infrastructure Institute (I3) at Iowa State University. The authors would like to express their gratitude to Prof. James Oliver and Prof. Arun Somani at Iowa State University for their technical and financial support.\n\nPublished - gnc2008chungCollision.pdf
", "abstract": "This paper presents at a class of new methods which explore and describe an unstructured environment according to the free space as seen by a vehicle within the environment.\nThe proposed methods use such sensor-based information to present a safe, goal-seeking path through the environment. The methods are suitable to both online, reactive pathnding and obstacle avoidance as well as online or offline global navigation and goal-seeking behaviours. Experimental results on ground vehicles and in simulation are presented to demonstrate the path-planning capabilities of the proposed methods.", "date": "2008-08", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics (AIAA)", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2008-7168", "id_number": "CaltechAUTHORS:20161221-111102659", "isbn": "9781605608082", "book_title": "AIAA Guidance, Navigation and Control Conference and Exhibit 2008", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161221-111102659", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)" }, { "agency": "Iowa State University" } ] }, "other_numbering_system": { "items": [ { "id": "2008-7168", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2008-7168", "primary_object": { "basename": "gnc2008chungCollision.pdf", "url": "https://authors.library.caltech.edu/records/vr2e0-bqz13/files/gnc2008chungCollision.pdf" }, "pub_year": "2008", "author_list": "Berg-Taylor, Kito; Seo, Keehong; et el." }, { "id": "https://authors.library.caltech.edu/records/y6shf-4hw45", "eprint_id": 72425, "eprint_status": "archive", "datestamp": "2023-08-19 23:23:26", "lastmod": "2023-10-23 22:33:25", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Ahsun-Umair", "name": { "family": "Ahsun", "given": "Umair" } }, { "id": "Slotine-J-J-E", "name": { "family": "Slotine", "given": "Jean-Jacques" }, "orcid": "0000-0002-7161-7812" } ] }, "title": "Attitude and Phase Synchronization of Formation Flying Spacecraft: Lagrangian Approach", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2008 by the American Institute of Aeronautics and Astronautics. \n\nThis work has benefitted from stimulating discussions with Dr. David W. Miller at MIT, Dr. Bong Wie at Iowa State University, and Dr. Jesse Leitner at the NASA Goddard Space Flight Center. The authors would like to acknowledge the constructive feedback from anonymous reviewers.\n\nSession: GNC-12: Dynamics and Control of Spacecraft Formations.\n\nPublished - AIAA2008_6472.pdf
", "abstract": "This article presents a unified synchronization framework with application to precision formation flying spacecraft. Central to the proposed innovation, in applying synchroniza-\ntion to both translational and rotational dynamics in the Lagrangian form, is the use of the distributed stability and performance analysis tool, called contraction analysis that yields exact nonlinear stability proofs. The proposed decentralized tracking control law synchronizes the attitude of an arbitrary number of spacecraft into a common time-varying trajectory with global exponential convergence. Moreover, a decentralized translational tracking control law based on phase synchronization is presented, thus enabling coupled translational and rotational maneuvers. While the translational dynamics can be adequately controlled by linear control laws, the proposed method permits highly nonlinear systems with nonlinearly coupled inertia matrices such as the attitude dynamics of space-craft whose large and rapid slew maneuvers justify the nonlinear control approach. The\nproposed method integrates both the trajectory tracking and synchronization problems in a single control framework.", "date": "2008-08", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics (AIAA)", "place_of_pub": "Reston, VA", "pagerange": "AIAA 2008-6472", "id_number": "CaltechAUTHORS:20161130-072236304", "isbn": "9781600869990", "book_title": "AIAA Guidance, Navigation and Control Conference and Exhibit : 18 August 2008 - 21 August 2008, Honolulu, Hawaii", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161130-072236304", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2008-6472", "primary_object": { "basename": "AIAA2008_6472.pdf", "url": "https://authors.library.caltech.edu/records/y6shf-4hw45/files/AIAA2008_6472.pdf" }, "pub_year": "2008", "author_list": "Chung, Soon-Jo; Ahsun, Umair; et el." }, { "id": "https://authors.library.caltech.edu/records/6mktx-z1j79", "eprint_id": 73079, "eprint_status": "archive", "datestamp": "2023-08-19 23:23:44", "lastmod": "2023-10-24 15:01:09", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "\u00c7elik-K", "name": { "family": "\u00c7elik", "given": "Koray" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Somani-A-K", "name": { "family": "Somani", "given": "Arun K." } } ] }, "title": "MVCSLAM: Mono-Vision Corner SLAM for Autonomous Micro-Helicopters in GPS Denied Environments", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2008 American Institute of Aeronautics and Astronautics. \n\nThe research reported in this article was in part supported by National Science Foundation (Grant ECCS-0428040), and Information Infrastructure Institute (I3). The authors thank Dr. David Jensen at Rockwell Collins Inc. for technical discussions and support.\n\nPublished - korayGNC2008.pdf
", "abstract": "We present a real-time vision navigation and ranging method (VINAR) for the purpose of Simultaneous Localization and Mapping (SLAM) using monocular vision. Our navigation strategy assumes a GPS denied unknown environment, whose indoor architecture is represented via corner based feature points obtained through a monocular camera. We experiment on a case study mission of vision based SLAM through a conventional maze of corridors in a large building with an autonomous Micro Aerial Vehicle (MAV). We propose a method for gathering useful landmarks from a monocular camera for SLAM use. We make use of the corners by exploiting the architectural features of the manmade indoors.", "date": "2008-08", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics (AIAA)", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2008-6670", "id_number": "CaltechAUTHORS:20161221-113250801", "isbn": "978-1-60086-999-0", "book_title": "AIAA Guidance, Navigation and Control Conference and Exhibit 2008", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161221-113250801", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "ECCS-0428040" }, { "agency": "Iowa State University" } ] }, "other_numbering_system": { "items": [ { "id": "2008-6670", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2008-6670", "primary_object": { "basename": "korayGNC2008.pdf", "url": "https://authors.library.caltech.edu/records/6mktx-z1j79/files/korayGNC2008.pdf" }, "pub_year": "2008", "author_list": "\u00c7elik, Koray; Chung, Soon-Jo; et el." }, { "id": "https://authors.library.caltech.edu/records/9z87k-85x97", "eprint_id": 87984, "eprint_status": "archive", "datestamp": "2023-09-29 01:32:15", "lastmod": "2024-01-14 20:28:20", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Breckinridge-J-B", "name": { "family": "Breckinridge", "given": "James" }, "orcid": "0000-0002-9488-098X" }, { "id": "Bryant-N", "name": { "family": "Bryant", "given": "Nevin" } }, { "id": "Lorre-J", "name": { "family": "Lorre", "given": "John" } } ] }, "title": "Innovative pupil topographies for sparse aperture telescopes and SNR", "ispublished": "unpub", "full_text_status": "public", "keywords": "telescopes, sparse apertures, image quality, signal-to-noise ratio, image processing", "note": "\u00a9 2008 Society of Photo-Optical Instrumentation Engineers (SPIE). \n\nThis research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, and was sponsored by the National Aeronautics and Space Administration (NASA).\n\nPublished - 70133E.pdf
", "abstract": "Since the first application of the telescope to astronomy in 1610, most new astronomical discoveries require larger and larger radiation collecting areas. Today, the twin 10-meter Keck telescopes are operational and several 30-meter-aperture class telescopes are being planned. Optical interferometers and sparse aperture ground telescopes for astronomy have been proposed and built. Fienup showed the dependence between exposure time and the dilution factor of the aperture needed to maintain image quality.1 Carpenter suggests a sparse aperture telescope system for the purpose of imaging across the surfaces of stars.2 This paper demonstrates that the ability to reconstruct images from white-light extended sources with different contrast levels also depends on the specific pupil topography that is applied to the telescope system. Signal-to-noise ratios for recorded images are calculated for scene contrast, pupil shape, detector full-well, detected photons, and exposure times.", "date": "2008-07-28", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "Art. No. 70133E", "id_number": "CaltechAUTHORS:20180718-162952782", "isbn": "9780819472236", "book_title": "Optical and Infrared Interferometry", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180718-162952782", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Sch\u00f6ller-M", "name": { "family": "Sch\u00f6ller", "given": "Markus" } }, { "id": "Danchi-W-C", "name": { "family": "Danchi", "given": "William C." } }, { "id": "Delplancke-", "name": { "family": "Delplancke", "given": "Fran\u00e7oise" } } ] }, "doi": "10.1117/12.787011", "primary_object": { "basename": "70133E.pdf", "url": "https://authors.library.caltech.edu/records/9z87k-85x97/files/70133E.pdf" }, "pub_year": "2008", "author_list": "Breckinridge, James; Bryant, Nevin; et el." }, { "id": "https://authors.library.caltech.edu/records/pg79s-mgw72", "eprint_id": 101836, "eprint_status": "archive", "datestamp": "2023-08-19 23:17:23", "lastmod": "2023-10-19 23:34:15", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Capece-A-M", "name": { "family": "Capece", "given": "Angela M." } }, { "id": "Polk-J-E", "name": { "family": "Polk", "given": "James E." } }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "Joseph E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "Current and Temperature Thresholds for Short-Term Oxygen Poisoning of Hollow Cathodes", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2008 by the American Institute of Aeronautics and Astronautics, Inc. The U.S. Government has a royalty-free license to exercise all rights under the copyright claimed herein for Governmental purposes. All other rights are reserved by the copyright owner. \n\nPublished Online: 15 Jun 2012.", "abstract": "Hollow cathodes that operate with impurities in the xenon propellant exhibit poisoning of the emitter surface, resulting in a higher surface work function and increased operating temperatures. The goal of this paper is to provide insight Into the physical processes responsible for cathode degradation during short-duration oxygen poisoning over a range of discharge currents and surface temperatures. The experimental results presented here show that the cathode is more susceptible to poisoning at higher oxygen concentration levels, lower discharge currents, and lower initial insert temperatures. The threshold current at which the emitter surface becomes susceptible to oxygen poisoning was determined to be between 8.24 A and 10.17 A for an oxygen concentration level of 10 ppm, and between 10.17 A and 12.35 A for oxygen concentration levels of 50 and 100 ppm. To determine the threshold surface temperature, further work must be conducted to isolate the effects of xenon ion sputtering and surface temperature on cathode operation during poisoning.", "date": "2008-07-21", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "id_number": "CaltechAUTHORS:20200310-143411569", "isbn": "978-1-60086-992-1", "book_title": "44th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200310-143411569", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2008-4813", "pub_year": "2008", "author_list": "Capece, Angela M.; Polk, James E.; et el." }, { "id": "https://authors.library.caltech.edu/records/v3czx-4hd35", "eprint_id": 102072, "eprint_status": "archive", "datestamp": "2023-08-19 23:17:30", "lastmod": "2023-10-19 23:48:16", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Przybylowski-J-N", "name": { "family": "Przybylowski", "given": "JoHanna N." } }, { "id": "Polk-J-E", "name": { "family": "Polk", "given": "James E." } }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "Joseph E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "Spatially Mapping the Ion Energy Distributions in Hollow Cathode Discharges", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2008 by the American Institute of Aeronautics and Astronautics, Inc. The U.S. Government has a royalty-free license to exercise all rights under the copyright claimed herein for Governmental purposes. All other rights are reserved by the copyright owner.", "abstract": "Distributions of ion energy-per-charge were collected with an electrostatic energy analyzer directed along various lines-of-sight in the near-plume region of a hollow cathode operating in a laboratory discharge chamber. While the analyzer was stationary, the cathode and anode assembly were mounted on a rotary and a linear stage, allowing measurements along the cathode axis and at off-axis angles up to 90\u00b0; the linear stage enabled translational motion which allowed for measurements parallel to the cathode axis. At angles below 45\u00b0, three distinct ion populations were identified: two low-energy narrow peaks and a broad high-energy \"tail\" with energies-per-charge in excess of 5 times the discharge voltage. Detection of low-energy ions above 45\u00b0 was not possible since they were confined by the anode voltage. At large angles, the intensity of the high-energy ion signal decreased to become indistinguishable from noise in the data system; however, based on previous results, the failure to detect high-energy ions at large angles has been attributed to the large distance between the ESA line-of-sight and the cathode axis increased from 0\u00b0 to 16\u00b0, the location of the low-energy ion peaks shift but there is no apparent difference in the high-energy ion tail. Increasing the separation angle further yields a decrease in intensity at all energies. For low energies-per-charge, the shape and intensity of the unidirectional ion-energy distribution does not change when the cathode is translated up to 2.5cm; however, as the distance from the cathode centerline increases, the signal intensity of the high-energy ions decreases in a manner similar to the decrease in high-energy ions seen with increasing angles above 30\u00b0. These results indicate that magneto-gas dynamic forced did not accelerate the ions observed in this experiment; additional experiments will elucidate the mass and energy dependence of the mechanisms responsible for high-energy ions.", "date": "2008-07-21", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2008-5206", "id_number": "CaltechAUTHORS:20200324-075425413", "isbn": "978-1-60086-992-1", "book_title": "44th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200324-075425413", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2008-5206", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2008-5206", "pub_year": "2008", "author_list": "Przybylowski, JoHanna N.; Polk, James E.; et el." }, { "id": "https://authors.library.caltech.edu/records/fhhy2-j4421", "eprint_id": 50198, "eprint_status": "archive", "datestamp": "2023-08-19 23:02:18", "lastmod": "2023-10-17 22:50:35", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Sharma-M", "name": { "family": "Sharma", "given": "M." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "J. M." } }, { "id": "Glumac-N-G", "name": { "family": "Glumac", "given": "N. G." } } ] }, "title": "Influence of thermochemistry on Mach reflection in\n hypersonic flow", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2008 by the American Institute of Aeronautics and Astronautics, Inc.\n\nAIAA 2008-5066.\n\nThis research was funded in part through AFOSR/MURI Grant FA9550-04-1-0425 with Dr. John Schmisseur as Technical Monitor.\n\nPublished - 385910.pdf
", "abstract": "Real gas thermochemistry can significantly impact the aerodynamics of hypersonic systems. For example, shock stand-off distance in front of a blunt body has been shown to depend on the degree of chemical\ndissociation. High temperature effects can also alter shock-shock interaction phenomena, but the degree of\nthe modification and its consequences can be challenging to predict. Sanderson et al. experimentally investigated oblique shock impingment on a bow shock (Edney type IV configuration) in a flow with significant\ngas dissociation. Previous studies had suggested significant increase in heat transfer at jet impingement\ndue to real gas effects, however, experiments showed no dependence of peak heat transfer rate on stagnation\nenthalpy. The influence of nonequilibrium gas chemistry on Mach and regular shock reflection has been investigated in a number of numerical studies. Burtschell et al. numerically investigated a wedge geometry\nlocated in a Mach 7 free stream, a setup similar to that used in the present experimental work. Mach stem\nheight and hysteresis behavior was examined. Burtschell et al. found a strong dependence of transition\nangles, Mach stem height and location on the gas flow model. For a given wedge angle, the inclusion of\nreal gas chemistry led to a significant decrease in Mach stem height. Chemical-vibration coupling, however,\nslightly increased the height of the Mach stem. Direct Monte-Carlo simulations of a shock reflection with\nand without real gas effects carried out by Gimelschein et al. also found a substantial effect on Mach stem\nheight and transition angle. However, an experimental study in dissociating nitrogen and carbon dioxide,\nionizing argon and frozen argon could detect no effect on the transition condition due to finite relaxation\nlength at the conditions of the experiment.\n\nIn the present work, we experimentally investigate a Mach reflection generated by two opposing wedges\nin a Mach 7.1 free stream. The main goal of this work is to determine directly what kinds of real gas effects\noccur behind a normal shock in a Mach reflection configuration for a previously selected run condition.\nExperiments are carried out in an expansion tube facility which is capable of simulating high enthalpy\nhypersonic flight conditions, and a significant degree of vibrational excitation and chemical dissociation are\nexpected behind the normal shock.\n\nIn high enthalpy gas flows, emission spectroscopy can be used to characterize the test gas composition\nand thermodynamic state. As impulse facilities, expansion tubes produce a challenging experimental environment for probe measurements with issues such as short test times, high temperatures and velocities, and\ndiaphragm fragmentation. The non-intrusive nature of spectroscopy makes it an attractive technique\nfor determining flow field properties in impulse facilities. Spectrally resolved studies have been previously\nused as a means towards characterizing high-enthalpy run conditions. Work completed at the X1 and X2\nsuperorbital expansion tube facilities used emission spectroscopy to measure electron number density behind\na bow shock and to identify sources of visible radiation. Time-resolved spectral methods were used in\nthe JX1 expansion tube facility to determine the useful test time. Using the CARS technique, temperature\nprofiles were determined for a hypervelocity blunt body flow field using the T3 shock tunnel facility. Using\nthe free piston shock tube/tunnel facility TCM2, laser spectroscopy was used for species identification and\nshock front temperature profile diagnostics and spontaneous Raman spectroscopy was used to analyze the\nself-luminosity of nitrogen hypersonic flows for varying enthalpy conditions.\n\nIn the current experiments, asymmetric wedges are used to generate a Mach stem, with a free shear layer\nat each triple point. Imaged spectroscopic measurements behind the Mach stem are presented. The spectra\nconfirms flow dissociation and verifies the appropriateness of a run condition which in the future is to be\nused towards investigating high-temperature effects upon shear layer structure in hypersonic flow.", "date": "2008-07", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "id_number": "CaltechAUTHORS:20141006-083036975", "isbn": "978-1-60086-992-1", "book_title": "44th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141006-083036975", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR) Multidisciplinary University Research Initiative (MURI)", "grant_number": "FA9550-04-1-0425" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2008-5066", "primary_object": { "basename": "385910.pdf", "url": "https://authors.library.caltech.edu/records/fhhy2-j4421/files/385910.pdf" }, "pub_year": "2008", "author_list": "Sharma, M.; Austin, J. M.; et el." }, { "id": "https://authors.library.caltech.edu/records/yhgba-w7z71", "eprint_id": 63993, "eprint_status": "archive", "datestamp": "2023-08-19 23:03:07", "lastmod": "2023-10-17 18:33:07", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Daly-S", "name": { "family": "Daly", "given": "Samantha" } }, { "id": "Bhattacharya-K", "name": { "family": "Bhattacharya", "given": "Kaushik" }, "orcid": "0000-0003-2908-5469" }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "Guruswami" }, "orcid": "0000-0002-2912-0001" } ] }, "title": "Deformation Behavior of a Shape Memory Alloy, Nitinol", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2008 ASME.\n\nPublished - 553_1.pdf
", "abstract": "Nickel-Titanium, commonly referred to as Nitinol, is a shape-memory alloy with numerous\napplications due to its superelastic nature and its ability to revert to a previously defined shape\nwhen deformed and then heated past a set transformation temperature. While the\ncrystallography and the overall phenomenology are reasonably well understood, much remains\nunknown about the deformation and failure mechanisms of these materials. These latter issues\nare becoming critically important as Nitinol is being increasingly used in medical devices and\nspace applications. The talk will describe the investigation of the deformation and failure of\nNitinol using an in-situ optical technique called Digital Image Correlation (DIC). With this\ntechnique, full-field quantitative maps of strain localization are obtained for the first time in\nthin sheets of Nitinol under tension. These experiments provide new information connecting\nprevious observations on the micro- and macro- scale. They show that martensitic\ntransformation initiates before the formation of localized bands, and that the strain inside the\nbands does not saturate when the bands nucleate. The effect of rolling texture, the validity of\nthe widely used resolved stress transformation criterion, and the role of geometric defects are\nexamined.", "date": "2008-07", "date_type": "published", "publisher": "American Society of Mechanical Engineering", "pagerange": "553-553", "id_number": "CaltechAUTHORS:20160127-072106515", "isbn": "978-0-7918-4835-7", "book_title": "Advanced Energy Systems; Advanced and Digital Manufacturing; Advanced Materials; Aerospace", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160127-072106515", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1115/ESDA2008-59187", "primary_object": { "basename": "553_1.pdf", "url": "https://authors.library.caltech.edu/records/yhgba-w7z71/files/553_1.pdf" }, "pub_year": "2008", "author_list": "Daly, Samantha; Bhattacharya, Kaushik; et el." }, { "id": "https://authors.library.caltech.edu/records/35x7h-x3x57", "eprint_id": 102164, "eprint_status": "archive", "datestamp": "2023-08-19 22:57:42", "lastmod": "2023-10-19 23:54:35", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "H. G." }, "orcid": "0000-0002-4903-8419" } ] }, "title": "Deriving Features of Reacting Hypersonic Flows from Gradients at Curved Shocks", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2008 by Hans G. Hornung. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.", "abstract": "The shock jump relations for gradients of flow variables are presented in the case of a uniform steady free stream with a curved shock that may trigger endothermic or exothermic chemical reaction. The rich information that can be obtained from these is used in order to derive field information for flow variables as well as details about the sonic line. This presentation collects, reviews and extends work that has been published previously in various places. Comparisons with experiment and with numerical computations are given in some cases. The gradient jump relations are Likely to be useful for higher-order numerical schemes that use shock fitting.", "date": "2008-06-23", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2008-4340", "id_number": "CaltechAUTHORS:20200330-080442903", "isbn": "978-1-60086-995-2", "book_title": "5th AIAA Theoretical Fluid Mechanics Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200330-080442903", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2008-4340", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2008-4340", "pub_year": "2008", "author_list": "Hornung, H. G." }, { "id": "https://authors.library.caltech.edu/records/5fhdm-h4b47", "eprint_id": 102083, "eprint_status": "archive", "datestamp": "2023-08-19 22:57:35", "lastmod": "2023-10-19 23:49:09", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "H. G." }, "orcid": "0000-0002-4903-8419" }, { "id": "Mouton-C-A", "name": { "family": "Mouton", "given": "C. A." } } ] }, "title": "Some More on Transition Between Regular and Mach Reflection of Shock Waves in Steady Flow (Invited)", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2008 by Hans G. Hornung. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.", "abstract": "A theoretical and experimental investigation was conducted to elucidate the mechanism by which transition from regular to Mach reflection can be initiated in the dual-solution domain. The Ludwieg Tube at GALCIT was equipped with a new Mach 4 nozzle and with devices to enable starting the flow with a double-wedge model. The flow In the Ludwieg Tube is sufficiently quiet to permit regular reflection up to about half way into the dual-solution domain. A theoretical animate of the strength of disturbance required to cause transition was obtained in the form of a relation between energy deposited and location of deposition. Experiments confirmed the nature of this relation. Mach stem heights and growth rates were measured and compared with previous computational and theoretical results. The results of this work add to the evidence that Mach reflection is the stable reflection state in the dual-solution domain.", "date": "2008-06-23", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2008-3845", "id_number": "CaltechAUTHORS:20200324-105755235", "isbn": "978-1-60086-989-1", "book_title": "38th Fluid Dynamics Conference and Exhibit", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200324-105755235", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2008-3845", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2008-3845", "pub_year": "2008", "author_list": "Hornung, H. G. and Mouton, C. A." }, { "id": "https://authors.library.caltech.edu/records/sfcqw-wdq90", "eprint_id": 72251, "eprint_status": "archive", "datestamp": "2023-08-19 22:37:20", "lastmod": "2023-10-23 20:33:05", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Berg-Taylor-K", "name": { "family": "Berg-Taylor", "given": "Kito" } }, { "id": "Seo-Keehong", "name": { "family": "Seo", "given": "Keehong" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Development of a Car-like Online Navigation Testbed", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2008 IEEE. \n\nDate of Conference: 18-20 May 2008. Date Added to IEEE Xplore: 27 June 2008. \n\nThis research was partially supported by the Air Force Office of Scientific Research (AFOSR) and the Information Infrastructure Institute (iCUBE) at Iowa State University. The authors are also grateful to Drs. Arun Somani and James Oliver for their support.\n\nPublished - 04554325.pdf
", "abstract": "We present new realtime path planning and collision avoidance algorithms for an autonomous rover equipped with a laser range finder to be used as a platform for multi-agent navigation and control in unknown environments. For successful navigation, such tasks as localization, map-building, and collision avoidance should be handled at the vehicle level. The proposed architecture covers these aspects of robotic path- planning in a modular and robust manner, allowing quicker development of more sophisticated path-planners. Using a conventional SLAM algorithm, a feature map and the location of the vehicle is obtained. The information for orientation and distance of the obstacles ahead is available from a laser range finder. The proposed collision avoidance algorithm provides multiple paths to guide the vehicle through the environment. The system acts as a self-contained extendable platform for development and testing of high-level pathfinders.", "date": "2008-05", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "337-342", "id_number": "CaltechAUTHORS:20161122-135542529", "isbn": "978-1-4244-2029-2", "book_title": "2008 IEEE International Conference on Electro/Information Technology", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161122-135542529", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)" }, { "agency": "Iowa State University" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/EIT.2008.4554325", "primary_object": { "basename": "04554325.pdf", "url": "https://authors.library.caltech.edu/records/sfcqw-wdq90/files/04554325.pdf" }, "pub_year": "2008", "author_list": "Berg-Taylor, Kito; Seo, Keehong; et el." }, { "id": "https://authors.library.caltech.edu/records/h0mb6-pfg24", "eprint_id": 72256, "eprint_status": "archive", "datestamp": "2023-08-19 22:37:25", "lastmod": "2024-01-13 20:20:48", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "\u00c7elik-K", "name": { "family": "\u00c7elik", "given": "Koray" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Somani-A-K", "name": { "family": "Somani", "given": "Arun" } } ] }, "title": "Mono-vision corner SLAM for indoor navigation", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2008 IEEE. \n\nDate of Conference: 18-20 May 2008. Date Added to IEEE Xplore: 27 June 2008.\n\nPublished - 04554326.pdf
", "abstract": "We present a real-time monocular vision based range measurement method for Simultaneous Localization and Mapping (SLAM) for an Autonomous Micro Aerial Vehicle (MAV) with significantly constrained payload. Our navigation strategy assumes a GPS denied manmade environment, whose indoor architecture is represented via corner based feature points obtained through a monocular camera. We experiment on a case study mission of vision based path-finding through a conventional maze of corridors in a large building.", "date": "2008-05", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "343-348", "id_number": "CaltechAUTHORS:20161122-143023693", "isbn": "978-1-4244-2029-2", "book_title": "IEEE International Conference on Electro/Information Technology, 2008", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161122-143023693", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/EIT.2008.4554326", "primary_object": { "basename": "04554326.pdf", "url": "https://authors.library.caltech.edu/records/h0mb6-pfg24/files/04554326.pdf" }, "pub_year": "2008", "author_list": "\u00c7elik, Koray; Chung, Soon-Jo; et el." }, { "id": "https://authors.library.caltech.edu/records/0sbd0-t6k79", "eprint_id": 88132, "eprint_status": "archive", "datestamp": "2023-08-19 22:30:17", "lastmod": "2024-01-14 20:29:08", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Khatri-D", "name": { "family": "Khatri", "given": "Devvrath" } }, { "id": "Daraio-C", "name": { "family": "Daraio", "given": "Chiara" }, "orcid": "0000-0001-5296-4440" }, { "id": "Rizzo-P", "name": { "family": "Rizzo", "given": "Piervincenzo" } } ] }, "title": "Highly nonlinear waves' sensor technology for highway infrastructures", "ispublished": "unpub", "full_text_status": "public", "keywords": "Highly nonlinear solitary waves, Nondestructive Evaluation, material characterization", "note": "\u00a9 2008 Society of Photo-Optical Instrumentation Engineers (SPIE). \n\nChiara Daraio and Piervincenzo Rizzo acknowledge the support of Caltech and Pitt startup funds, respectively.\n\nPublished - 69340U.pdf
", "abstract": "This paper describes preliminary results towards the development of an innovative NDE/SHM scheme for material characterization and defect detection based on the generation of highly nonlinear solitary waves (HNSWs). HNSWs are stress waves that can form and travel in highly nonlinear systems (i.e. granular, layered, fibrous or porous materials) with a finite spatial dimension independent on the wave amplitude. Compared to conventional linear waves, the generation of HNSWs does not rely on the use of electronic equipment (such as an arbitrary function generator) and on the response of piezoelectric crystals or other transduction mechanism. HNSWs possess unique tunable properties that provide a complete control over tailoring: 1) the choice of the wave's width (spatial size) for defects investigation, 2) the composition of the excited train of waves (i.e. number and separation of the waves used for testing), and 3) their amplitude and velocity. HNSWs are excited onto concrete samples and steel rebar. The first pilot study of this ongoing effort between Caltech and the University of Pittsburgh is presented.", "date": "2008-04-08", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "Art. No. 69340U", "id_number": "CaltechAUTHORS:20180723-114843030", "isbn": "9780819471208", "book_title": "Nondestructive Characterization for Composite Materials, Aerospace Engineering, Civil Infrastructure, and Homeland Security 2008", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180723-114843030", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech" }, { "agency": "University of Pittsburgh" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Shull-P-J", "name": { "family": "Shull", "given": "Peter J." } }, { "id": "Wu-H-Felix", "name": { "family": "Wu", "given": "H. Felix" } }, { "id": "Diaz-A-A", "name": { "family": "Diaz", "given": "Aaron A." } }, { "id": "Vogel-D-W", "name": { "family": "Vogel", "given": "Dietmar W." } } ] }, "doi": "10.1117/12.775848", "primary_object": { "basename": "69340U.pdf", "url": "https://authors.library.caltech.edu/records/0sbd0-t6k79/files/69340U.pdf" }, "pub_year": "2008", "author_list": "Khatri, Devvrath; Daraio, Chiara; et el." }, { "id": "https://authors.library.caltech.edu/records/j5q84-a3730", "eprint_id": 102166, "eprint_status": "archive", "datestamp": "2023-08-19 22:29:50", "lastmod": "2023-10-19 23:54:41", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Deng-Xiaowei", "name": { "family": "Deng", "given": "X." } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "S." }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Computation of Partially Inflated Shapes of Stratospheric Balloon Structures", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2008 by X. Deng and S. Pellegrino. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission. \n\nWe thank the NASA ULDB team for their contribution to this research. In particular, we are grateful to Henry Cathey for kindly providing test data and Rodger Farley, Jim Rand and David Wakefield for helping us through numerous discussions This research was supported by the NASA Balloon Program Office (contract monitor Danny Ball).\n\nAccepted Version - DengAIAA2008.pdf
", "abstract": "This paper studies the relationship between height, volume and stress distribution in a superpressure pumpkin balloon with the differential pressure applied to the balloon. Two different approaches are presented. A simple two-dimensional solution based on previous work and a novel, detailed finite element simulation that provides three-dimensional solutions are investigated. It is found that the finite element solution provides a much better agreement with experimental results for the case of a flat facet ULDB balloon. It is also found that a region of tensile hoop stress remains in the crown region of the balloon until the bottom pressure becomes negative. This region prevents the formation of clefts in the balloon and keeps its shape axisymmetric.", "date": "2008-04-07", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2008-2133", "id_number": "CaltechAUTHORS:20200330-082659500", "isbn": "978-1-60086-993-8", "book_title": "49th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, 16th AIAA/ASME/AHS Adaptive Structures Conference, 10th AIAA Non-Deterministic Approaches Conference, 9th AIAA Gossamer Spacecraft Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200330-082659500", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA" } ] }, "other_numbering_system": { "items": [ { "id": "2008-2133", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2008-2133", "primary_object": { "basename": "DengAIAA2008.pdf", "url": "https://authors.library.caltech.edu/records/j5q84-a3730/files/DengAIAA2008.pdf" }, "pub_year": "2008", "author_list": "Deng, X. and Pellegrino, S." }, { "id": "https://authors.library.caltech.edu/records/ata8h-dpk39", "eprint_id": 102165, "eprint_status": "archive", "datestamp": "2023-08-19 22:29:44", "lastmod": "2023-10-19 23:54:38", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Mallikarachchi-H-M-Y-C", "name": { "family": "Mallikarachchi", "given": "H. M. Y. C." } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "S." }, "orcid": "0000-0001-9373-3278" } ] }, "title": "Simulation of Quasi-Static Folding and Deployment of Ultra-Thin Composite Structures", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2008 by H.M.Y.C. Mallikarachchi and S. Pellegrino. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission. \n\nWe thank Dr Ahmad Kueh and Dr Michael Sutcliffe for helpful discussions. We are grateful to Mr J. Ellis (Hexcel, UK) for providing materials. HM thanks the Cambridge Commonwealth Trust for financial support.\n\nAccepted Version - Mallikarachchi2008.pdf
", "abstract": "This paper presents a detailed study of the folding and deployment of a slotted tube hinge made from a two-ply laminate of carbon-fibre reinforced plastic. A physical model of a particular version of this binge has been used to carry out quasi-static deployment tests and this process has been fully captured through a finite element simulation. The first stage in this simulation was to generate the fully folded, strained configuration of the hinge. The second stage in the simulation was to gradually decrease the relative rotation between the ends until it became zero. By analysing the in-plane strains and out-of-plane curvatures in the folded configuration we have confirmed that the particular hinge design that has been studied could be folded without permanent damage.", "date": "2008-04-07", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2008-2053", "id_number": "CaltechAUTHORS:20200330-081459739", "isbn": "978-1-60086-993-8", "book_title": "49th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, 16th AIAA/ASME/AHS Adaptive Structures Conference, 10th AIAA Non-Deterministic Approaches Conference, 9th AIAA Gossamer Spacecraft Forum", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200330-081459739", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Cambridge Commonwealth Trust" } ] }, "other_numbering_system": { "items": [ { "id": "2008-2053", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2008-2053", "primary_object": { "basename": "Mallikarachchi2008.pdf", "url": "https://authors.library.caltech.edu/records/ata8h-dpk39/files/Mallikarachchi2008.pdf" }, "pub_year": "2008", "author_list": "Mallikarachchi, H. M. Y. C. and Pellegrino, S." }, { "id": "https://authors.library.caltech.edu/records/wwk3n-mmd65", "eprint_id": 100982, "eprint_status": "archive", "datestamp": "2023-08-19 21:58:49", "lastmod": "2023-10-19 22:18:29", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Nango-Ayaka", "name": { "family": "Nango", "given": "Ayaka" } }, { "id": "Inaba-Kazuaki", "name": { "family": "Inaba", "given": "Kazuaki" } }, { "id": "Kojima-Takayuki", "name": { "family": "Kojima", "given": "Takayuki" } }, { "id": "Yamamoto-Makoto", "name": { "family": "Yamamoto", "given": "Makoto" } } ] }, "title": "Numerical Study of Detonation Interaction with a Single-Stage Axial Turbine", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2008 by the American Institute of Aeronautics and Astronautics, Inc. \n\nPublished online: 19 June 2012.", "abstract": "In the present paper, we examine a single two-dimensional detonation wave propagating in a single-stage axial flow turbine. The objective or this study is the computation of the detailed now field and estimating the turbine work output. Turbine extracted work for a single operation is evaluated by energy balance and mechanical approaches. Adiabatic efficiencies at the rotor obtained by energy balance predict 50 to 70% and shows good agreement with the efficiencies by mechanic.al approach, depending on the rotor speed.", "date": "2008-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2008-985", "id_number": "CaltechAUTHORS:20200129-081539732", "isbn": "978-1-62410-128-1", "book_title": "46th AIAA Aerospace Sciences Meeting and Exhibit", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200129-081539732", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2008-985", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2008-985", "pub_year": "2008", "author_list": "Nango, Ayaka; Inaba, Kazuaki; et el." }, { "id": "https://authors.library.caltech.edu/records/5gp7d-qcw51", "eprint_id": 100910, "eprint_status": "archive", "datestamp": "2023-08-19 21:58:46", "lastmod": "2023-10-19 22:14:23", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Takashima-Yasuhiro", "name": { "family": "Takashima", "given": "Yasuhiro" } }, { "id": "Kasahara-Jiro", "name": { "family": "Kasahara", "given": "Jiro" } }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "Joseph E." }, "orcid": "0000-0003-3181-9310" }, { "id": "Funaki-Ikkoh", "name": { "family": "Funaki", "given": "Ikkoh" } } ] }, "title": "Impulse Generated by a Shock Tube in a Vacuum", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2008 by the American Institute of Aeronautics and Astronautics, Inc. \n\nPublished online: 19 June 2012.", "abstract": "Detonation tube specific impulse increases with decreasing ambient pressure for fully-filled conditions in a sub-atmospheric environment. In the present study, we use an open-end shock tube to simulate a detonation tube and investigate the dependence of the specific impulse on the propellant fraction, i.e., partial filing, in vacuum operation. The impulse is experimentally determined by hanging the shock tube in a ballistic pendulum arrangement inside a vacuum chamber. The shock tube driver section has a fixed length of 0.1 m and is filled to 1 MPa with various gases including helium, hydrogen, nitrogen, argon, and sulfur hexafluoride. The pressure inside the vacuum chamber is 5 Pa. The shock tube had constant area and different lengths (0-1.2 m) of the open-end driven sections (extension tubes) are used to vary the fraction or gas filling the shock tube (fill fraction) between 7.8% and 100%. The specific impulse is a weak function of extension tube length but varies strongly with the gas type. Dimensional analysis is used to correlate the data and we show that similar to data from detonation tubes, it is possible to correlate specific impulse with a single parameter that takes into account the lime scale for depressurization. The specific impulse is predicted using the method or characteristics ignoring two-dimensional and rarified gas effects at the tube exit. In agreement with the experiments, the specific impulse is predicted to increase slightly with extension tube length and vary inversely with the square root of the molecular weight of the gas. The specific impulse observed for SF\u2086 is about 25% higher that observed for the other gases with the same extension tube lengths, indicating an effect or vibration-translational energy exchange on the exhaust velocity.", "date": "2008-01", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2008-987", "id_number": "CaltechAUTHORS:20200124-145500606", "isbn": "978-1-62410-128-1", "book_title": "46th AIAA Aerospace Sciences Meeting and Exhibit", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200124-145500606", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2008-987", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2008-987", "pub_year": "2008", "author_list": "Takashima, Yasuhiro; Kasahara, Jiro; et el." }, { "id": "https://authors.library.caltech.edu/records/r0hxv-dj034", "eprint_id": 18731, "eprint_status": "archive", "datestamp": "2023-08-19 21:44:05", "lastmod": "2023-10-20 16:42:50", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Inaba-Kazuaki", "name": { "family": "Inaba", "given": "Kazuaki" } }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "Joseph E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "Flexural waves in fluid-filled tubes subject to axial impact", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2008 ASME.\nThis research was sponsored by the Office of Naval Research, DOD MURI on Mechanics and Mechanisms of Impulse Loading, Damage and Failure of Marine Structures and Materials (ONR Grant No. N00014-06-1-0730), program manager Dr. Y. D. S. Rajapakse. We thanks Chris Krok for his work on the first generation of experiments and Tim Curran for his work on data processing and image analysis.\n\nPublished - Inaba2009p8193Proceedings_Of_The_Asme_Pressure_Vessels_And_Piping_Conference_Vol_4.pdf
", "abstract": "We experimentally studied the propagation of coupled fluid stress waves and tube flexural waves generated through projectile impact along the axis of a water filled tube. We tested mild steel tubes, 38-40 mm inner diameter and wall thickness of 0.8, 6.4, and 12.7 mm. A steel impactor was accelerated using an air cannon and struck a polycarbonate buffer placed on the top water surface within the tube. Elastic flexural waves were observed for impact speeds of 5-10 m/s and plastic waves appeared for impact speeds approaching 20 m/s for a 0.8 mm thickness tube. We observed primary wave speeds of 1100 m/s in a 0.8 mm thickness tube, increasing to the water sound speed with 6.4 and 12.7 mm thickness tubes. Comparison of our measurements in the 0.8 mm thickness tube with Skalak's water hammer theory indicates reasonable agreement between predicted and measured peak strains as a function of the impact buffer speed. For thick-wall tubes, the correlation between experimentally determined peak pressures and strains reveals the importance of corrections for the through-wall stress distribution.", "date": "2008", "date_type": "published", "publisher": "ASME", "pagerange": "273-282", "id_number": "CaltechAUTHORS:20100618-095626855", "isbn": "978-0-7918-4827-2", "book_title": "Proceedings of the ASME Pressure Vessels and Piping Conference, Vol. 4", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100618-095626855", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-06-1-0730" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1115/PVP2008-61672", "primary_object": { "basename": "Inaba2009p8193Proceedings_Of_The_Asme_Pressure_Vessels_And_Piping_Conference_Vol_4.pdf", "url": "https://authors.library.caltech.edu/records/r0hxv-dj034/files/Inaba2009p8193Proceedings_Of_The_Asme_Pressure_Vessels_And_Piping_Conference_Vol_4.pdf" }, "pub_year": "2008", "author_list": "Inaba, Kazuaki and Shepherd, Joseph E." }, { "id": "https://authors.library.caltech.edu/records/2q2r7-k2q35", "eprint_id": 50127, "eprint_status": "archive", "datestamp": "2023-08-23 16:50:31", "lastmod": "2023-10-17 22:32:15", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "McGilvray-M", "name": { "family": "McGilvray", "given": "M." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "J. M." } }, { "id": "Sharma-M", "name": { "family": "Sharma", "given": "M." } }, { "id": "Jacobs-P-A", "name": { "family": "Jacobs", "given": "P. A." } }, { "id": "Morgan-R-G", "name": { "family": "Morgan", "given": "R. G." } } ] }, "title": "Diagnostic Modelling of an Expansion Tube Operating Condition for a Hypersonic Free Shear Layer Experiment", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2007 University of Queensland.\n\nThe authors would like to acknowledge the University of\nQueensland's graduate research office for financial support in\nthe form of a Graduate Research Student Travel Award for\nMatthew McGilvray to visit the University of Illinois. All\nthe simulations detailed in this paper were undertaken on the\nBlackhole cluster computer located at the Centre for Hypersonics,\nUniversity of Queensland. Financial support for the cluster\ncomputer was provided by SUN Microsystems and by the\nQueensland State government under the Smart State program.\nWe thank Rowan Gollan, Carolyn Jacobs, Daniel Potter and\nMarlies Hankel for running the University of Queensland cluster\ncomputer. Also, help with the finite rate simulations was\nprovided by Daniel Potter and Rowan Gollan.\n\nPublished - Austin_Dec2007.pdf
", "abstract": "Computational simulations of the AIR-1 test condition in the\nUniversity of Illinois' Hypervelocity Expansion Tube were conducted\nto verify facility operation and to obtain free stream\nproperties that are otherwise difficult to measure. Two types\nof simulation were undertaken. The first was a one-dimensional\nsimulation of the entire facility and the second was a hybrid simulation,\ncombining a one-dimensional simulation of the shock\ntube section with a two-dimensional simulation of the acceleration\ntube. The one-dimensional simulation matched the experimental\ndata well, however the two-dimensional simulation\ndid not initially match the experimental measurements of shock\nspeed and test gas pitot pressure. Further investigation showed\nthe shock speed discrepancy was consistent with air contamination\ninto the acceleration tube and subsequent two-dimensional\nsimulations assuming 10% air contamination showed reasonable\nagreement with experimental data.\n\nUsing data taken from the two-dimensional simulation of the\nexpansion tube as a transient inflow condition, modelling was\nundertaken of a free shear layer experiment being conducted in\nthe facility. Results from equilibrium, finite rate, and perfect\ngas models were compared. The finite rate simulation provides\nthe best agreement with experimental Schlieren images, with\nthe simulation capturing the major flow structures seen in experiments.", "date": "2007-12", "date_type": "published", "publisher": "University of Queensland", "place_of_pub": "St Lucia, Queensland, Australia", "pagerange": "385-393", "id_number": "CaltechAUTHORS:20140930-144402979", "isbn": "9781864998948", "book_title": "Proceedings of the Sixteenth Australasian Fluid Mechanics Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140930-144402979", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "University of Queensland" }, { "agency": "SUN Microsystems" }, { "agency": "Queensland State Government" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "primary_object": { "basename": "Austin_Dec2007.pdf", "url": "https://authors.library.caltech.edu/records/2q2r7-k2q35/files/Austin_Dec2007.pdf" }, "pub_year": "2007", "author_list": "McGilvray, M.; Austin, J. M.; et el." }, { "id": "https://authors.library.caltech.edu/records/vptdk-feh08", "eprint_id": 72250, "eprint_status": "archive", "datestamp": "2023-08-19 21:35:38", "lastmod": "2023-10-23 20:33:02", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Slotine-J-J-E", "name": { "family": "Slotine", "given": "Jean-Jacques E." } } ] }, "title": "Cooperative Robot Control and Synchronization of Lagrangian Systems", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2007 IEEE. \n\nDate of Conference: 12-14 Dec. 2007. Date Added to IEEE Xplore: 21 January 2008.\n\nPublished - 04434036.pdf
", "abstract": "This article presents a simple synchronization framework that can be directly applied to cooperative control of multi-agent systems and oscillation synchronization in robotic manipulation and teleoperation. A dynamical network of multiple Lagrangian systems is constructed by adding diffusive couplings to otherwise freely moving or flying robots. The proposed decentralized tracking control law synchronizes an arbitrary number of robots into a common trajectory with global exponential convergence. The proposed strategy is much simpler than earlier work in terms of both the computational load and the required signals. Furthermore, in contrast with prior work which used simple double integrator models, the proposed method permits highly nonlinear systems and is further extended to time-delayed communications, adaptive control, partial-joint coupling, and leader-follower networks.", "date": "2007-12", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "2504-2509", "id_number": "CaltechAUTHORS:20161122-133156700", "isbn": "978-1-4244-1497-0", "book_title": "46th IEEE Conference on Decision and Control, 2007", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161122-133156700", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/CDC.2007.4434036", "primary_object": { "basename": "04434036.pdf", "url": "https://authors.library.caltech.edu/records/vptdk-feh08/files/04434036.pdf" }, "pub_year": "2007", "author_list": "Chung, Soon-Jo and Slotine, Jean-Jacques E." }, { "id": "https://authors.library.caltech.edu/records/vjdwn-che80", "eprint_id": 103670, "eprint_status": "archive", "datestamp": "2023-08-19 21:29:38", "lastmod": "2024-01-15 04:31:22", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Pandolfi-A", "name": { "family": "Pandolfi", "given": "Anna" }, "orcid": "0000-0002-7084-7456" }, { "id": "Ortiz-M", "name": { "family": "Ortiz", "given": "Michael" }, "orcid": "0000-0001-5877-4824" } ] }, "title": "Finite Element Analysis of Nonsmooth Frictional Contact", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Frictional contact, non-smooth contact, finite elements, variational formulations", "note": "\u00a9 Springer 2007. \n\nAP acknowledges the support of the Italian MIUR PRIN-2005 programme, Protocol No. 2005085973.", "abstract": "A nonsmooth contact class of algorithms were introduced by Kane et al. [1] and extended to the case of friction by Pandolfi et. al [2]. The formulation specifically addresses geometries for which neither normals nor gap functions can be properly defined, e.g. bodies with corners. The formulation provides the incremental displacements in variational form, following from a minimum principle. Selected numerical examples of application of the algorithm are presented here.", "date": "2007-11-19", "date_type": "published", "publisher": "Springer", "place_of_pub": "Dordrecht", "pagerange": "57-76", "id_number": "CaltechAUTHORS:20200603-101544417", "isbn": "9781402064043", "book_title": "IUTAM Symposium on Computational Methods in Contact Mechanics", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200603-101544417", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Ministero dell'Istruzione, dell'Universita e della Ricerca (MIUR)", "grant_number": "2005085973" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Wriggers-P", "name": { "family": "Wriggers", "given": "Peter" } }, { "id": "Nackenhorst-U", "name": { "family": "Nackenhorst", "given": "Udo" } } ] }, "doi": "10.1007/978-1-4020-6405-0_4", "pub_year": "2007", "author_list": "Pandolfi, Anna and Ortiz, Michael" }, { "id": "https://authors.library.caltech.edu/records/ydene-qhh92", "eprint_id": 50218, "eprint_status": "archive", "datestamp": "2023-08-19 21:21:52", "lastmod": "2023-10-17 22:51:25", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Morgenstern-M-S", "name": { "family": "Morgenstern", "given": "Mara S." } }, { "id": "Chakraborty-P", "name": { "family": "Chakraborty", "given": "Pinaki" } }, { "id": "Zandonade-P", "name": { "family": "Zandonade", "given": "Paulo" } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "Joanna M." } }, { "id": "Kieffer-S-W", "name": { "family": "Kieffer", "given": "Susan W." } } ] }, "title": "Experiments on the Gas Dynamics of the Mt. St. Helens 1980 Lateral Blast", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2007 by the Volcanological Society of Japan.\n\nPublished - Austin_11-P-149.pdf
", "abstract": "Field evidence suggests that the lateral blast in the 1980\nMt. St. Helens eruption behaved like an underexpanded\njet flow. We conduct two experiments to investigate this\nhypothesis. In our first experiment, we use the\ncompressible flow--shallow-water analogy to measure the\ngeometry of the shock structure around the\nunderexpanded jet, which is comparable with the position\nof the interface between the direct and channelized blast\nzones described by Kieffer (1981). Also, Kieffer and\nSturtevant (1988) identified furrows created by the blast\nwhich were possibly formed by scouring due to Goertler\nvortices induced by curvature in the terrain. In our second\nexperiment, carried out in a compressible flow laboratory,\nwe investigate an additional Goertler vortex generation\nmechanism due to the curvature of the shear layer\nadjacent to the intercepting shocks in the underexpanded\njet. These experiments allow for a more-detailed scrutiny\nof the underexpanded jet--lateral blast analogy proposed\nby Kieffer (1981).", "date": "2007-11", "date_type": "published", "publisher": "Volcanological Society of Japan", "id_number": "CaltechAUTHORS:20141006-145032564", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141006-145032564", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "primary_object": { "basename": "Austin_11-P-149.pdf", "url": "https://authors.library.caltech.edu/records/ydene-qhh92/files/Austin_11-P-149.pdf" }, "pub_year": "2007", "author_list": "Morgenstern, Mara S.; Chakraborty, Pinaki; et el." }, { "id": "https://authors.library.caltech.edu/records/5983c-yvz35", "eprint_id": 73061, "eprint_status": "archive", "datestamp": "2023-08-19 20:48:44", "lastmod": "2023-10-24 15:00:24", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Slotine-J-J-E", "name": { "family": "Slotine", "given": "Jean-Jacques" } }, { "id": "Miller-D-W", "name": { "family": "Miller", "given": "David" }, "orcid": "0000-0001-6099-0614" } ] }, "title": "New Control Strategies for Underactuated Tethered Formation Flight Spacecraft", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2007 American Institute of Aeronautics and Astronautics. \n\nThe authors would like to gratefully acknowledge the NASA Goddard Space Flight Center (Contract Monitor Dr. David Leisawitz) for both financial and technical support for the MIT-SSL and Payload Systems (PSI) SPHERES Tether program. The authors also thank the MIT SPHERES team including Danielle Adams, Alvar Saenz-Otero and Christophe Mandy for the technical discussions and support.\n\nPublished - GNC2007underactuated.pdf
", "abstract": "We introduce a decentralized attitude control strategy that can dramatically reduce the usage of propellant, by taking full advantage of the physical coupling of the tether. Moti-\nvated by a controllability analysis, indicating that both spin-up and relative attitudes are fully controllable by the reaction wheels, we report the first propellant-free underactuated linear and nonlinear control results for tethered formation flying spacecraft. We take a nonlinear control approach to underactuated tethered formation flying spacecraft, whose lack of full state feedback linearizability, along with their complex nonholonomic behavior, characterizes the difficult nonlinear control problem. We introduce several nonlinear control laws that are more efficient in tracking time-varying trajectories than linear control. We also extend our decentralized control approach to underactuated tethered systems,\nthereby eliminating the need for any inter-satellite communication.", "date": "2007-08-23", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2007-6858", "id_number": "CaltechAUTHORS:20161221-102258243", "isbn": "9781563479045", "book_title": "AIAA Guidance, Navigation and Control Conference and Exhibit 2007", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161221-102258243", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA Goddard Space Flight Center" } ] }, "other_numbering_system": { "items": [ { "id": "2007-6858", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2007-6858", "primary_object": { "basename": "GNC2007underactuated.pdf", "url": "https://authors.library.caltech.edu/records/5983c-yvz35/files/GNC2007underactuated.pdf" }, "pub_year": "2007", "author_list": "Chung, Soon-Jo; Slotine, Jean-Jacques; et el." }, { "id": "https://authors.library.caltech.edu/records/q43q3-svn21", "eprint_id": 73059, "eprint_status": "archive", "datestamp": "2023-08-19 20:42:58", "lastmod": "2023-10-24 15:00:18", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Ahsun-Umair", "name": { "family": "Ahsun", "given": "Umair" } }, { "id": "Slotine-J-J-E", "name": { "family": "Slotine", "given": "Jean-Jacques" } }, { "id": "Miller-D-W", "name": { "family": "Miller", "given": "David" }, "orcid": "0000-0001-6099-0614" } ] }, "title": "Application of Synchronization to Cooperative Control and Formation Flight of Spacecraft", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2007 American Institute of Aeronautics and Astronautics. \n\nThe authors gratefully acknowledge anonymous reviewers comments for the previous and current versions of the paper. Also, Soon-Jo Chung appreciates Prof. Bong Wie for stimulating discussions.\n\nPublished - GNC2007FFsync.pdf
", "abstract": "This article presents a simple synchronization framework with application to synchronization control of formation \nflying spacecraft. A dynamical network of multiple Lagrangian systems is constructed by adding diffusive couplings to otherwise freely flying spacecraft. The proposed tracking control law synchronizes an arbitrary number of spacecraft into a common time-varying trajectory with global exponential convergence. The proposed strategy is much simpler than earlier work in terms of both the computational load and the required signals. Furthermore, in contrast with prior work which used simple double integrator models, the proposed method permits highly nonlinear systems and is further extended to adaptive synchronization, partial-state coupling, and time-delayed communications.", "date": "2007-08", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics (AIAA)", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2007-6861", "id_number": "CaltechAUTHORS:20161221-100404214", "isbn": "9781563479045", "book_title": "AIAA Guidance, Navigation and Control Conference and Exhibit 2007", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161221-100404214", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2007-6861", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2007-6861", "primary_object": { "basename": "GNC2007FFsync.pdf", "url": "https://authors.library.caltech.edu/records/q43q3-svn21/files/GNC2007FFsync.pdf" }, "pub_year": "2007", "author_list": "Chung, Soon-Jo; Ahsun, Umair; et el." }, { "id": "https://authors.library.caltech.edu/records/n9zfz-3zm05", "eprint_id": 67602, "eprint_status": "archive", "datestamp": "2023-08-19 20:33:02", "lastmod": "2023-10-18 21:19:25", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bonanos-A-M", "name": { "family": "Bonanos", "given": "Aristides M." } }, { "id": "Bergthorson-J-M", "name": { "family": "Bergthorson", "given": "Jeffrey M." } }, { "id": "Dimotakis-P-E", "name": { "family": "Dimotakis", "given": "Paul E." } } ] }, "title": "Molecular Mixing and Flowfield Measurements in an Expansion-Ramp Combustor: Supersonic Flow", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2007 by the authors.", "abstract": "This paper studies the level of molecular mixing and aerodynamic effects for supersonic flow in an \"air\" stream, with variable \"fuel\" mass injection and chemical heat release, in a flow configuration that has potential utility in dual-mode ramjet/scramjet combustors. \"Fuel\" is injected through a backward-facing expansion ramp at a rate insufficient to provide the entrainment requirements of the shear layer produced by the flow separation, which attaches to the lower guide wall. Part of the shear layer flow is directed upstream forming a recirculation zone that enhances mixing and provides flameholding benefits. Significant (passive) control authority over the flow is demonstrated by using variable mass injection through the ramp, and also by varying the level of heat release in the flow. molecular mixing was measured employing the hypergolic hydrogen-fluorine chemical reaction. The amount of mixing for the expansion-ramp geometry is found to be higher than in classical free shear layers. However, as in free shear layers, the level of mixing is found to decrease with increasing top-stream velocity.", "date": "2007-07", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "pagerange": "Paper AIAA 2007-5417", "id_number": "CaltechAUTHORS:20160602-162603294", "isbn": "978-1-62410-011-6", "book_title": "43rd AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160602-162603294", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2007-5417", "pub_year": "2007", "author_list": "Bonanos, Aristides M.; Bergthorson, Jeffrey M.; et el." }, { "id": "https://authors.library.caltech.edu/records/kgq5x-1k806", "eprint_id": 102825, "eprint_status": "archive", "datestamp": "2023-08-19 20:29:59", "lastmod": "2023-10-20 00:31:57", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Marineau-E-C", "name": { "family": "Marineau", "given": "Eric C." } }, { "id": "Schetz-J-A", "name": { "family": "Schetz", "given": "Joseph A." } }, { "id": "Neel-R-E", "name": { "family": "Neel", "given": "Reece E." } } ] }, "title": "Computational and Experimental Investigation of Supersonic Convection on a Laser Heated Target", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2007 by the American Institute of Aeronautics and Astronautics, Inc. \n\nSession: TP-10: High Speed Flows.", "abstract": "This research concerns the development and validation of simulation of the beam-target Interaction to determine the target temperature distribution as a function of time for a given target geometry, surface radiation intensity and free stream flow condition. The effect of a turbulent supersonic flow was investigated both numerically and experimentally. \n\nExperiments were In the Virginia Tech supersonic wind tunnel with a Mach 4 nozzle, ambient total temperature, total pressure of 1.1 x 10\u2076 Pa and Reynolds number of 5 x 10\u2077/m. The target consisted of a 6.35 mm stainless steel plate painted flat black. The target was irradiated with a 300 Watt continuous beam Ytterbium fiber laser generating a 4 mm Gaussian beam at 1.08 micron 10 cm from the leading edge where a 4 mm turbulent boundary layer prevailed. An absorbed laser power of 65, 81, 101, 120 Watts was used leading to a maximum heat flux between 1035 to 1910 W/cm\u00b2. The target surface and backside temperatures were measured using a mid-wave infrared camera. The backside temperature was also measured using eight type-K thermocouples. \n\nTwo tests are made, one with the flow-on and the other with the flow-off. For the flow-on case, the laser is turned on aft.er the tunnel starts and the flow reaches a steady state. \n\nFor the flow-off case, the plate is heated at the same power but without the supersonic flow. The cooling effect is seen by subtracting the flow-on temperature from the flow-off\ntemperature. This temperature subtraction is useful in canceling the bias errors such that the overall uncertainty is significantly reduced. \n\nThe GASP conjugate heat transfer algorithm was used to simulate the experiments at 81 and 65 Watts. Most computations were performed using the Spalart-Allmaras turbulence model on a 280,320 cell grid. A grid convergence study was performed. \n\nCompared to the 65 Watt case, the 81 Watt case displays more asymmetry and a region of increased cooling is found upstream. The increased asymmetry was also seen on the backside by both the thermocouple and infrared temperature measurements. The computation underpredicts the surface temperature by 7% for the flow-off case. For both thef 65 and 81 Watt cases, cooling is underpredicted at the surface near the center. For all power settings, convective cooling significantly increases the time required to reach a given temperature.", "date": "2007-06-25", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Reston, VA", "pagerange": "Art. No. 2007-4147", "id_number": "CaltechAUTHORS:20200428-071016951", "isbn": "978-1-62410-010-9", "book_title": "39th AIAA Thermophysics Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200428-071016951", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2007-4147", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2007-4147", "pub_year": "2007", "author_list": "Marineau, Eric C.; Schetz, Joseph A.; et el." }, { "id": "https://authors.library.caltech.edu/records/t60pp-2n657", "eprint_id": 41440, "eprint_status": "archive", "datestamp": "2023-08-19 19:42:25", "lastmod": "2024-01-13 06:04:15", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Moghaddam-A-N", "name": { "family": "Moghaddam", "given": "Abbas N." } }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "Morteza" }, "orcid": "0000-0003-0754-4193" } ] }, "title": "Structure and function relationship of human heart from DENSE MRI", "ispublished": "unpub", "full_text_status": "public", "keywords": "cardiac mechanics, image-based biomechanical models, strain, structure, function, tissue deformation", "note": "\u00a9 2007 SPIE.\n\nPublished - Gharib_2007pL5111.pdf
", "abstract": "The study here, suggests a macroscopic structure for the Left Ventricle (LV), based on the heart kinematics which is\nobtained through imaging. The measurement of the heart muscle deformation using the Displacement ENcoding with\nStimulated Echoes (DENSE) MRI, which describes the heart kinematics in the Lagrangian frame work, is used to\ndetermine the high resolution patterns of true myocardial strain. Subsequently, the tangential Shortening Index (SI) and\nthe thickening of the LV wall are calculated for each data point. Considering the heart as a positive-displacement pump,\nthe contribution of each segment of LV in the heart function, can be determined by the SI and thickening of the wall in\nthe same portion. Hence the SI isosurfaces show the extent and spatial distribution of the heart activity and reveals its\nmacro structure. The structure and function of the heart are, therefore, related which in turn results in a macroscopic\nmodel for the LV. In particular, it was observed that the heart functionality is not uniformly distributed in the LV, and\nthe regions with greater effect on the pumping process, form a band which wraps around the heart. These results, which\nare supported by the established histological evidence, may be considered as a landmark in connecting the structure and\nfunction of the heart through imaging. Furthermore, the compatibility of this model with microscopic observations\nabout the fiber direction is investigated [1]. This method may be used for planning as well as post evaluation of the\nventriculoplasty.", "date": "2007-02-17", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers", "place_of_pub": "Bellingham, WA", "pagerange": "Art. No. L5111", "id_number": "CaltechAUTHORS:20130920-101057355", "isbn": "978-0-8194-6629-7", "book_title": "Medical Imaging 2007: Physiology, Function, and Structure from Medical Images", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130920-101057355", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Manduca-A", "name": { "family": "Manduca", "given": "Armando" } }, { "id": "Hu-Xiaoping", "name": { "family": "Hu", "given": "Xiaoping" } } ] }, "doi": "10.1117/12.711269", "primary_object": { "basename": "Gharib_2007pL5111.pdf", "url": "https://authors.library.caltech.edu/records/t60pp-2n657/files/Gharib_2007pL5111.pdf" }, "pub_year": "2007", "author_list": "Moghaddam, Abbas N. and Gharib, Morteza" }, { "id": "https://authors.library.caltech.edu/records/7pqc3-73s36", "eprint_id": 50122, "eprint_status": "archive", "datestamp": "2023-08-19 19:27:49", "lastmod": "2023-10-17 22:32:03", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Dufrene-A", "name": { "family": "Dufrene", "given": "A." } }, { "id": "Sharma-M", "name": { "family": "Sharma", "given": "M." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "J. M." } } ] }, "title": "Design and Characterization of a Hypervelocity Expansion Tube Facility", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2007 by the University of Illinois. All rights reserved. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.\n\nAAA 2007-1327.\n\nThis research was funded in part through a Multi-University Research Initiative (MURI)\ngranted by the Air Force Office of Scientific Research (AFOSR), with Dr John Schmisseur\nas Technical Monitor. Special thanks to Matthew D. Parker for test section design and\nconstruction, and data acquisition system installation, to Matt McGilvray for the design of\nthe transducer mounts, and to Dr. Richard Morgan for helpful discussions.\n\nPublished - 385650.pdf
", "abstract": "We report on the design and characterization of a 152 mm diameter expansion tube capable of accessing a range of high enthalpy test conditions\nwith Mach numbers up to 7.1 for aerodynamic studies. Expansion tubes\nhave the potential to offer a wide range of test flow conditions as gas acceleration is achieved through interaction with an unsteady expansion wave\nrather than expansion through a fixed area ratio nozzle. However, the range\nof test flow conditions is in practice limited by a number of considerations\nsuch as short test time and large amplitude flow disturbances. We present\na generalized design strategy for small-scale expansion tubes. As a starting\npoint, ideal gas dynamic calculations for optimal facility design to maximize\ntest time at a given Mach number test condition are presented, together\nwith a correction for the expansion head reflection through a non-simple\nregion. A compilation of practical limitations that have been identified for\nexpansion tube facilities such as diaphragm rupture and flow disturbance\nminimization is then used to map out a functional design parameter space.\nExperimentally, a range of test conditions have been verified through pitot\npressure measurements and analysis of schlieren images of flow over simple\ngeometries. To date there has been good agreement between theoretical\nand experimental results.", "date": "2007-01", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "id_number": "CaltechAUTHORS:20140930-100227099", "isbn": "978-1-62410-012-3", "book_title": "45th AIAA Aerospace Sciences Meeting and Exhibit", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140930-100227099", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR) Multidisciplinary University Research Initiative (MURI)" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2007-1327", "primary_object": { "basename": "385650.pdf", "url": "https://authors.library.caltech.edu/records/7pqc3-73s36/files/385650.pdf" }, "pub_year": "2007", "author_list": "Dufrene, A.; Sharma, M.; et el." }, { "id": "https://authors.library.caltech.edu/records/c17q0-vxx53", "eprint_id": 103700, "eprint_status": "archive", "datestamp": "2023-08-19 19:23:55", "lastmod": "2024-01-15 04:31:24", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Yu-Rena-C", "name": { "family": "Yu", "given": "Rena C." }, "orcid": "0000-0003-4176-0324" }, { "id": "Pandolfi-A", "name": { "family": "Pandolfi", "given": "Anna" }, "orcid": "0000-0002-7084-7456" }, { "id": "Ortiz-M", "name": { "family": "Ortiz", "given": "Michael" }, "orcid": "0000-0001-5877-4824" } ] }, "title": "A 3D Cohesive Investigation on Branching for Brittle Materials", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "branching instabilities, cohesive models, brittle fracture, finite elements", "note": "\u00a9 Springer 2007. \n\nAP acknowledges the support of the Italian MIUR PRIN-2005 programme, Protocol no. 2005085973. RCY thanks the Spanish Ministerio de Educaci\u00f3n y Ciencia for the funding through the Programa Ram\u00f3n y Cajal.", "abstract": "Recently, Fineberg and Sharon conducted dynamic crack propagation experiments in PMMA and soda lime glass [1, 2, 3, 4, 5, 6, 7]. They pointed out some notable features of micro-branching instabilities in brittle materials, and their experiments raised a considerable interest for the brittle fracture dynamics. In this paper we present some numerical results on brittle fracture obtained by using cohesive theories of fracture. In the numerical calculations, the branching instability is a natural outcome of the explicit formulation. The cohesive model captures the basic features of experiments, such as the transition of the crack surface from smooth to hackled with increasing energy flux, and the power-law functional form of the profile of the crack branches.", "date": "2007", "date_type": "published", "publisher": "Springer Netherlands", "place_of_pub": "Dordrecht", "pagerange": "139-151", "id_number": "CaltechAUTHORS:20200604-144115576", "isbn": "9781402065293", "book_title": "IUTAM Symposium on Discretization Methods for Evolving Discontinuities", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200604-144115576", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Ministero dell'Istruzione, dell'Universita e della Ricerca (MIUR)", "grant_number": "2005085973" }, { "agency": "Ministerio de Educaci\u00f3n y Ciencia (MEC)" }, { "agency": "Ram\u00f3n y Cajal Programme" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Combescure-A", "name": { "family": "Combescure", "given": "Alain" } }, { "id": "De-Borst-R", "name": { "family": "De Borst", "given": "Ren\u00e9" } }, { "id": "Belytschko-T", "name": { "family": "Belytschko", "given": "Ted" } } ] }, "doi": "10.1007/978-1-4020-6530-9_8", "pub_year": "2007", "author_list": "Yu, Rena C.; Pandolfi, Anna; et el." }, { "id": "https://authors.library.caltech.edu/records/5vxe9-r5c93", "eprint_id": 50794, "eprint_status": "archive", "datestamp": "2023-08-19 19:18:12", "lastmod": "2023-10-18 14:31:30", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "McKeon-B-J", "name": { "family": "McKeon", "given": "Beverley" }, "orcid": "0000-0003-4220-1583" }, { "id": "Engler-R", "name": { "family": "Engler", "given": "Rolf" } } ] }, "title": "Pressure Measurement Systems", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2007 Springer.", "abstract": "Measurements of the steady pressure in a fluid flow may be required to determine other thermodynamic properties, to determine forces on a body due to the pressure distribution over it, or in order to determine the dynamic head and flow velocity (for further details on the latter see Sect. 5.1. Pressure is a scalar representation of molecular activity, a measure of the nondirectional molecular motions. Thus it must, by definition, be measured by a device at rest relative to the flow. Whilst the common practice in the fluid mechanics community is to denote the pressure as static (as opposed to the coordinate-dependent total pressure, Sect. 3.1), this terminology introduces a fundamental redundancy. \n\nIn practice, pressure is commonly measured both at walls and in the freestream using the types of measurement device shown in Fig. 4.1 connected to a transducer of suitable sensitivity and range. The orifice of a small wall tapping represents a simple way to obtain the pressure impressed on the wall by the external flow. So-called static pressure tubes approximate the local fluid pressure in the freestream if the disturbance presented to the flow can either be accounted for or is not large to begin with. However this can only ever be strictly true for steady laminar flow due to the normal velocity component introduced when a flow becomes turbulent. Measurement of freestream pressure is one of the hardest challenges in fluid mechanics.\nFig. 4.1\n\nThis chapter addresses measurement of pressure using wall tappings (Sect. 4.1) and static pressure tubes (Sect. 4.2), and especially errors due to the intrusive flow presence of real, finite-sized devices and calibrations to correct for these. Bryer and Pankhurst [4.1] and Chue [4.2] provided seminal monographs on the general topic of pressure probes in 1971 and 1975, respectively, which give detailed descriptions of measurement devices, coverage of the background to the various corrections and a survey of older data. The topic is covered here more concisely, with a view to\npractical use by the engineer, and with reference to modern literature. The reader is referred to Bryer and Pankhurst [4.1] and Chue [4.2] for further details on most sections. \n\nIn more recent years a further method for obtaining pressure on the surface of a wind tunnel model has been developed, based on pressure sensitive paints (PSP). The introduction of PSP provides a method to measure the pressure on the surface of a model directly without the transducers and tubing associated with conventional means. A paint, the luminescence of which is dependent on air pressure, is applied to the surface of a wind tunnel model and the pressure distribution is obtained from the images produced by proper illumination. In Sect. 4.4 the basics of PSP are discussed and further subsections address in detail different paints, paint application procedures, imaging systems and image processing. In discussing the achievable accuracy of PSP techniques, both the spatial and temporal resolution is examined. The thermal sensitivity of the paint dye is introduced and this is closely linked to temperature-sensitive paints (TSP), as discussed in Chap. 7, Sect. 7.4.", "date": "2007", "date_type": "published", "publisher": "Springer-Verlag", "place_of_pub": "Berlin, Germany", "pagerange": "179-214", "id_number": "CaltechAUTHORS:20141024-122054736", "isbn": "978-3-540-25141-5", "book_title": "Springer Handbook of Experimental Fluid Mechanics", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141024-122054736", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Tropea-C", "name": { "family": "Tropea", "given": "Cameron" } }, { "id": "Yarin-A-L", "name": { "family": "Yarin", "given": "Alexander L." } }, { "id": "Foss-J-F", "name": { "family": "Foss", "given": "John F." } } ] }, "doi": "10.1007/978-3-540-30299-5_4", "pub_year": "2007", "author_list": "McKeon, Beverley and Engler, Rolf" }, { "id": "https://authors.library.caltech.edu/records/x8p9d-qky48", "eprint_id": 19981, "eprint_status": "archive", "datestamp": "2023-08-19 19:11:13", "lastmod": "2024-01-13 00:01:48", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hill-D-J", "name": { "family": "Hill", "given": "D. J." } }, { "id": "Pantano-C", "name": { "family": "Pantano", "given": "C." } }, { "id": "Pullin-D-I", "name": { "family": "Pullin", "given": "D. I." } } ] }, "title": "Large-Eddy Simulation of Richtmyer-Meshkov Instability", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2007 Springer.\n\nThis work was supported by the Advanced Simulation and Computing (ASC) Program under subcontract no. B341492 of DOE contract W-7405-ENG-48. The authors would like to acknowledge the many helpful conversations with P.E. Dimotakis and D.I. Meiron.", "abstract": "We present results from large-eddy simulations (LES) of three-dimensional Richtmyer-Meshkov (RM) instability in a rectangular tube with reshock off the tube endwall. A hybrid numerical method is used that is shock capturing but\nwhich reverts to a centered scheme with low numerical viscosity in regions of smooth flow. The subgrid-scale (SGS) model is the stretched-vortex (SV) model [1]. The\nshock strength, tube geometry, gas composition, initial conditions and initial interface disturbance were tailored to the experimental conditions of Vetter & Sturtevant\n[2] with shock Mach number M_s = 1.5, density ratio r = 5, and constituent gases air and SF_6. Use of the SV SGS model allows continuation of radial velocity spectra in the center-plane of the mixing layer, to subgrid scales, including the effect of anisotropy and self-consistent calculation of the viscous cutoff scale.", "date": "2007", "date_type": "published", "publisher": "Springer", "pagerange": "263-271", "id_number": "CaltechAUTHORS:20100916-112754310", "isbn": "978-3-540-34233-5", "book_title": "Complex Effects in Large Eddy Simulations", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100916-112754310", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Advanced Simulation and Computing (ASC) Program, DOE", "grant_number": "B341492" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Kassinos-S", "name": { "family": "Kassinos", "given": "Stavros" } }, { "id": "Langer-C-A", "name": { "family": "Langer", "given": "Carlos A." } }, { "id": "Iaccarino-G", "name": { "family": "Iaccarino", "given": "Gianluca" } }, { "id": "Moin-Parviz", "name": { "family": "Moin", "given": "Parviz" } } ] }, "doi": "10.1007/978-3-540-34234-2_19", "pub_year": "2007", "author_list": "Hill, D. J.; Pantano, C.; et el." }, { "id": "https://authors.library.caltech.edu/records/9hm3f-5t356", "eprint_id": 69214, "eprint_status": "archive", "datestamp": "2023-08-22 07:58:13", "lastmod": "2024-01-13 16:52:37", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Rosakis-A-J", "name": { "family": "Rosakis", "given": "A. J." }, "orcid": "0000-0003-0559-0794" }, { "id": "Xia-K", "name": { "family": "Xia", "given": "K." } }, { "id": "Lykotrafitis-G", "name": { "family": "Lykotrafitis", "given": "G." } }, { "id": "Kanamori-H", "name": { "family": "Kanamori", "given": "H." }, "orcid": "0000-0001-8219-9428" } ] }, "title": "Dynamic Shear Rupture in Frictional Interfaces: Speeds, Directionality, and Modes", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Homogeneous and bimaterial system; Laboratory earthquakes; Particle velocimetry; Photoelasticity; Rupture directionality; Rupture modes; Sub-Rayleigh to supershear transition; Supershear earthquake rupture", "note": "\u00a9 2007 Elsevier B.V. \n\nThis chapter is reproduced from the previous edition, Volume 4, pp. 153\u2013192. \n\nThe authors gratefully acknowledge the support of NSF (Grant EAR 0207873), the US Department of Energy (Grant DE-FG52-06NA 26209), and the consistent support of the Office of Naval Research (Grant N00014-03-1-0435) and MURI (Grant N000140610730) through Dr. Y.D.S. Rajapakse, Program Manager.", "abstract": "The goal in designing dynamic frictional experiments simulating earthquake rupture has been to create a testing environment or platform which could reproduce some of the basic physics governing the rupture dynamics of crustal earthquakes while preserving enough simplicity so that clear conclusions can be obtained by pure observation. In this chapter, we first review past and recent experimental work on dynamic shear rupture propagation along frictional interfaces. The early experimental techniques are discussed in relation to recent experimental simulations of earthquakes which feature advanced diagnostics of high temporal and spatial resolution. The high-resolution instrumentation enables direct comparison between the experiments and data recorded during natural earthquakes. The experimental results presented in this chapter are examined in light of seismological observations related to various natural large rupture events and of recent theoretical and numerical development in the understanding of frictional rupture. In particular, the physics and conditions leading to phenomena such as supershear rupture growth, sub-Rayleigh to supershear rupture transition, and rupture directionality in inhomogeneous systems are discussed in detail. Finally, experiments demonstrating the attainability of various rupture modes (crack-like, pulse-like, and mixed) are presented and discussed in relation to theoretical and numerical predictions.", "date": "2007", "date_type": "published", "publisher": "Elsevier", "place_of_pub": "Amsterdam", "pagerange": "183-213", "id_number": "CaltechAUTHORS:20160726-082744533", "isbn": "978-0-12-409548-9", "book_title": "Reference Module in Earth Systems and Environmental Sciences", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160726-082744533", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR 0207873" }, { "agency": "Department of Energy (DOE)", "grant_number": "DE-FG52-06NA 26209" }, { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-03-1-0435" }, { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-06-10730" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/B978-0-444-53802-4.00072-5", "pub_year": "2007", "author_list": "Rosakis, A. J.; Xia, K.; et el." }, { "id": "https://authors.library.caltech.edu/records/5y0gd-w1k02", "eprint_id": 97893, "eprint_status": "archive", "datestamp": "2023-08-22 07:58:46", "lastmod": "2023-10-18 16:51:17", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Dimotakis-P-E", "name": { "family": "Dimotakis", "given": "P. E." } }, { "id": "Lang-D-B", "name": { "family": "Lang", "given": "D. B." } }, { "id": "Lombeyda-S", "name": { "family": "Lombeyda", "given": "S." } }, { "id": "Lindheim-J", "name": { "family": "Lindheim", "given": "J." } } ] }, "title": "An Investigation of Scalar Dispersion in Grid Turbulence", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Fluid Mechanics; Release Point; Passive Scalar; Gaussian Profile; Transverse Distance", "note": "\u00a9 2007 Tsinghua University Press & Springer.", "abstract": "The structure of scalar dispersion from a continuous release point was investigated for moderate Reynolds number flow in grid turbulence. Using laser-induced fluorescence techniques, laser-volume scanning, a custom-designed fast-readout CCD focal plane array, and high-speed digital-imaging/-acquisition/-storage techniques, the instantaneous three-dimensional structure of a passive scalar was investigated in flow in water (high Schmidt number). Laser Doppler and scalar-correlation velocimetry were employed to measure th flow speed entering the test section and in the interrogated volume. Such scalar-dispersion structure away from the release point is typically modeled assuming a Gaussian profile. This provides a good description for the mean scalar profile as a function of the transverse distance from a line parallel with the flow and downstream of the release point, as also confirmed by experiment (Yamamoto & Sato 1979, Gad-el-Hak & Morton 1979, Nakamura et al. 1987, Sawford 2001). The instantaneous three-dimensional structure, however, reveals a rich topology of scalar structures that was found to persist in the volume interrogated, spanning a distance from the grid and release point between 22 and 30 grid mesh lengths, which is in the self-similar grid-turbulence regime where the present three-dimensional scalar-field measurements were conducted.", "date": "2007", "date_type": "published", "publisher": "Springer", "place_of_pub": "Berlin", "pagerange": "7", "id_number": "CaltechAUTHORS:20190814-140334393", "isbn": "978-3-540-75994-2", "book_title": "New Trends in Fluid Mechanics Research", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190814-140334393", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Zhuang-F-G", "name": { "family": "Zhuang", "given": "F. G." } }, { "id": "Li-J-C", "name": { "family": "Li", "given": "J. C." } } ] }, "doi": "10.1007/978-3-540-75995-9_2", "pub_year": "2007", "author_list": "Dimotakis, P. E.; Lang, D. B.; et el." }, { "id": "https://authors.library.caltech.edu/records/0j2yr-7gs25", "eprint_id": 50237, "eprint_status": "archive", "datestamp": "2023-08-19 18:25:06", "lastmod": "2023-10-17 22:52:05", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kolinski-John", "name": { "family": "Kolinski", "given": "John" } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "Joanna" } }, { "id": "Gioia-Gustavo", "name": { "family": "Gioia", "given": "G." } }, { "id": "Chakraborty-Pinaki", "name": { "family": "Chakraborty", "given": "Pinaki" } }, { "id": "Kieffer-Susan-W", "name": { "family": "Kieffer", "given": "Susan" } } ] }, "title": "Annular waves on the surface of impact-formed tektites", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2006 American Physical Society. \n\nDate submitted: 04 Aug 2006. \n\nAbstract ID: BAPS.2006.DFD.FD.2\n\nPublished - MWS_DFD06-2006-001200.pdf
", "abstract": "Tektites are naturally\noccurring pieces of glass formed by melting of terrestrial rocks during a meteorite\nimpact. The most unusual tektites, known as Australites, were formed by an impact\nat an unknown site in Austro-Asia, and are found in a large strewn field covering\nAustralia. These tektites solidified on ascent through the earth's atmosphere, and\npartially remelted during re-entry. The thin remelted layer on the front surface\nshows distinct flanges with annular wavy structures. We propose that the annular\nwavy structure is a manifestation of surface waves on the flow of the thin layer.", "date": "2006-08-04", "date_type": "published", "publisher": "American Physical Society", "id_number": "CaltechAUTHORS:20141007-134123303", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141007-134123303", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "primary_object": { "basename": "MWS_DFD06-2006-001200.pdf", "url": "https://authors.library.caltech.edu/records/0j2yr-7gs25/files/MWS_DFD06-2006-001200.pdf" }, "pub_year": "2006", "author_list": "Kolinski, John; Austin, Joanna; et el." }, { "id": "https://authors.library.caltech.edu/records/tdmae-5j834", "eprint_id": 72423, "eprint_status": "archive", "datestamp": "2023-08-19 18:22:38", "lastmod": "2023-10-23 22:33:17", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" } ] }, "title": "Nonlinear Model Reduction and Decentralized Control of Tethered Formation Flight by Oscillation Synchronization", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2006 American Institute of Aeronautics and Astronautics.\n\nThe author is grateful to Prof. Jean-Jacques Slotine and Prof. David W. Miller for stimulating discussions.\n\nPublished - AIAA2006-6589.pdf
", "abstract": "This paper describes a fully decentralized nonlinear control law for spinning tethered formation flight, based on exploiting geometric symmetries to reduce the original nonlinear dynamics into simpler stable dynamics. Motivated by oscillation synchronization in biological systems, we use contraction theory to prove that a control law stabilizing a single-tethered spacecraft can also stabilize arbitrary large circular arrays of spacecraft, as well as the three inline configuration. The convergence result is global and exponential. Numerical simulations and experimental results using the SPHERES testbed validate the\nexponential stability of the tethered formation arrays by implementing a tracking control law derived from the reduced dynamics.", "date": "2006-08", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics (AIAA)", "place_of_pub": "Reston, VA", "pagerange": "Art. No.2006-6589", "id_number": "CaltechAUTHORS:20161130-065345609", "isbn": "978-1-62410-046-8", "book_title": "AIAA Guidance, Navigation, and Control Conference and Exhibit 2006", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161130-065345609", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "2006-6589", "name": "AIAA Paper" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2006-6589", "primary_object": { "basename": "AIAA2006-6589.pdf", "url": "https://authors.library.caltech.edu/records/tdmae-5j834/files/AIAA2006-6589.pdf" }, "pub_year": "2006", "author_list": "Chung, Soon-Jo" }, { "id": "https://authors.library.caltech.edu/records/zye4v-vf888", "eprint_id": 22521, "eprint_status": "archive", "datestamp": "2023-08-19 18:20:53", "lastmod": "2023-10-23 16:05:31", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kheradvar-A", "name": { "family": "Kheradvar", "given": "Arash" } }, { "id": "Milano-M", "name": { "family": "Milano", "given": "Michele" } }, { "id": "Gorman-R-C", "name": { "family": "Gorman", "given": "Robert C." } }, { "id": "Gorman-J-H-III", "name": { "family": "Gorman", "given": "Joseph H., III" } }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "Morteza" } } ] }, "title": "Estimation of elastic and viscous properties of the left ventricle based on annulus plane harmonic behavior", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2006 IEEE.\n\nManuscript received December 15, 2005. This work was supported in\npart by NIH grants HL-63954, HL-71137, HL-73021 and HL-76560.\n\n", "abstract": "Assessment of left ventricular (LV) function\nwith an emphasis on contractility has been a challenge\nin cardiac mechanics during the recent decades. The LV\nfunction is usually described by the LV pressurevolume\n(P-V) diagram. The standard P-V diagrams are\neasy to interpret but difficult to obtain and require\ninvasive instrumentation for measuring the\ncorresponding volume and pressure data. In the present\nstudy, we introduce a technique that can estimate the\nviscoelastic properties of the LV based on harmonic\nbehavior of the ventricular chamber and it can be\napplied non-invasively as well. The estimation technique\nis based on modeling the actual long axis displacement\nof the mitral annulus plane toward the cardiac base as a\nlinear damped oscillator with time-varying coefficients.\nThe time-varying parameters of the model were\nestimated by a standard Recursive Linear Least\nSquares (RLLS) technique. LV stiffness at end-systole\nand end diastole was in the range of 61.86-136.00\ndyne/g.cm and 1.25-21.02 dyne/g.cm, respectively. The\nonly input used in this model was the long axis\ndisplacement of the annulus plane, which can also be\nobtained non-invasively using tissue Doppler or MR\nimaging.", "date": "2006-08", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "616-619", "id_number": "CaltechAUTHORS:20110225-110616172", "isbn": "1-4244-0032-5", "book_title": "28th Annual International Conference of the IEEE Engineering in Medicine and Biology Society", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110225-110616172", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NIH", "grant_number": "HL-63954" }, { "agency": "NIH", "grant_number": "HL-71137" }, { "agency": "NIH", "grant_number": "HL-73021" }, { "agency": "NIH", "grant_number": "HL-76560" } ] }, "other_numbering_system": { "items": [ { "id": "9220485", "name": "INSPEC Accession Number" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/IEMBS.2006.259713", "primary_object": { "basename": "Kheradvar2006p88782006_28Th_Annual_International_Conference_Of_The_Ieee_Engineering_In_Medicine_And_Biology_Society_Vols_1-15.pdf", "url": "https://authors.library.caltech.edu/records/zye4v-vf888/files/Kheradvar2006p88782006_28Th_Annual_International_Conference_Of_The_Ieee_Engineering_In_Medicine_And_Biology_Society_Vols_1-15.pdf" }, "pub_year": "2006", "author_list": "Kheradvar, Arash; Milano, Michele; et el." }, { "id": "https://authors.library.caltech.edu/records/0v5v5-5xf02", "eprint_id": 50124, "eprint_status": "archive", "datestamp": "2023-08-23 16:49:54", "lastmod": "2023-10-17 22:32:11", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Massa-L", "name": { "family": "Massa", "given": "L." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "J. M." } }, { "id": "Jackson-T-L", "name": { "family": "Jackson", "given": "T. L." } } ] }, "title": "Triple point shear-layers in gaseous detonation waves", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2006 by the American Institute of Aeronautics and Astronautics, Inc.\n\nAIAA 2006-5275.\n\nLM and TLJ were supported by the U.S. Department of Energy through the University of California\nunder subcontract number B341494. This work was supported in part by funding from the ONR with Dr.\nGabriel Roy as technical monitor.\n\nPublished - 385652.pdf
", "abstract": "Recent experiments have shown intriguing regions of intense luminescence or \"hot spots\"\nin the vicinity of triple point shear-layers in propagating gaseous detonation waves. Localized explosions have also been observed to develop in these fronts. These features were\nobserved in higher effective activation energy mixtures, but not in lower effective activation\nenergy mixtures. We investigate the possibility that the increased lead shock oscillation\nthrough a cell cycle in higher activation energy mixtures may result in a significantly\nincreased disparity in the induction time on either side on the triple point shear-layer,\nincreasing the probability that shear-layer instability may develop between reacted and\nunreacted gas streams. We carry out two-dimensional simulations with detailed chemical\nkinetics to examine the nature of the triple point shear-layer in three mixtures with different effective activation energy. In the low activation energy mixture, large scale vortical\nstructures are observed to occur downstream of the ignition distance; these structures do\nnot have a noticeable effect on the reaction. In higher effective activation energy mixtures,\na transverse ignition front develops near the interface between the two gas streams and\nresults in a rapidly propagating reaction front. The transverse ignition front develops due\nto molecular diffusion across the shear-layer between hot and cold gas streams.", "date": "2006-07", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "id_number": "CaltechAUTHORS:20140930-102211599", "isbn": "978-1-62410-038-3", "book_title": "42nd AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140930-102211599", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Department of Energy (DOE)", "grant_number": "B341494" }, { "agency": "Office of Naval Research (ONR)" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2006-5275", "primary_object": { "basename": "385652.pdf", "url": "https://authors.library.caltech.edu/records/0v5v5-5xf02/files/385652.pdf" }, "pub_year": "2006", "author_list": "Massa, L.; Austin, J. M.; et el." }, { "id": "https://authors.library.caltech.edu/records/hwgs5-vjm80", "eprint_id": 72220, "eprint_status": "archive", "datestamp": "2023-08-19 18:11:01", "lastmod": "2023-10-23 20:28:26", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lang-D-B", "name": { "family": "Lang", "given": "Daniel" } }, { "id": "Lombeyda-S-V", "name": { "family": "Lombeyda", "given": "Santiago" } }, { "id": "Lindheim-J", "name": { "family": "Lindheim", "given": "Jan" } }, { "id": "Dimotakis-P-E", "name": { "family": "Dimotakis", "given": "Paul" } } ] }, "title": "Laser scanning of three-dimensional time-varying fluid phenomena", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2006 ACM.\n\nSupplemental Material - a57-lang-high.mov
Supplemental Material - a57-lang-low.mov
", "abstract": "Time-varying three-dimensional CFD simulations have been at\nthe center of many of the modern computational, physical, and movie special-effect challenges. Results are presented on the first full-field, three-dimensional, time-varying scanning of fluid phenomena. The discussion includes a description of the acquisition hardware, the data-acquisition methodology, the geometrical (space and time) and image corrections applied, and the visualization results and analysis. The results of the threedimensional\nfield capability on computational and physical\nmodels, new challenges it brings to the visualization field, and new possible applications are also discussed.", "date": "2006-07", "date_type": "published", "publisher": "ACM", "place_of_pub": "New York, NY", "pagerange": "Art. No. 57", "id_number": "CaltechAUTHORS:20161121-160244975", "isbn": "1-59593-364-6", "book_title": "SIGGRAPH '06 ACM SIGGRAPH 2006 Sketches", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161121-160244975", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Finnegan-J", "name": { "family": "Finnegan", "given": "John" } } ] }, "doi": "10.1145/1179849.1179920", "primary_object": { "basename": "a57-lang-high.mov", "url": "https://authors.library.caltech.edu/records/hwgs5-vjm80/files/a57-lang-high.mov" }, "related_objects": [ { "basename": "a57-lang-low.mov", "url": "https://authors.library.caltech.edu/records/hwgs5-vjm80/files/a57-lang-low.mov" } ], "pub_year": "2006", "author_list": "Lang, Daniel; Lombeyda, Santiago; et el." }, { "id": "https://authors.library.caltech.edu/records/r3bx2-2rd03", "eprint_id": 72246, "eprint_status": "archive", "datestamp": "2023-08-19 18:04:23", "lastmod": "2024-01-13 20:20:44", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Adams-Danielle", "name": { "family": "Adams", "given": "Danielle" } }, { "id": "Saenz-Otero-A", "name": { "family": "Saenz-Otero", "given": "Alvar" } }, { "id": "Kong-Edmund-M", "name": { "family": "Kong", "given": "Edmund M." } }, { "id": "Miller-D-W", "name": { "family": "Miller", "given": "David W." }, "orcid": "0000-0001-6099-0614" }, { "id": "Leisawitz-D-T", "name": { "family": "Leisawitz", "given": "David" } }, { "id": "Lorenzini-E", "name": { "family": "Lorenzini", "given": "Enrico" } }, { "id": "Sell-S", "name": { "family": "Sell", "given": "Steve" } } ] }, "title": "SPHERES Tethered Formation Flight Testbed: Advancements in Enabling NASA's SPECS Mission", "ispublished": "unpub", "full_text_status": "public", "keywords": "Stellar interferometer, space tether, formation flight", "note": "\u00a9 2006 International Society for Optical Engineering. \n\nThe authors would like to gratefully acknowledge NASA for both financial and technical support for the MITSSL and PSI SPHERES Tether program. This work has been sponsored under NASA Phase II SBIR contract (Contract No.: NNG05CA09C).\n\nPublished - 62680B_1.pdf
", "abstract": "This paper reports on efforts to control a tethered formation flight spacecraft array for NASA's SPECS mission using the SPHERES test-bed developed by the MIT Space Systems Laboratory. Specifically, advances in methodology and experimental results realized since the 2005 SPIE paper are emphasized. These include a new test-bed setup with a reaction wheel assembly, a novel relative attitude measurement system using force torque sensors, and modeling of non-ideal tethers to account for tether vibration modes. The nonlinear equations of motion of multi-vehicle tethered spacecraft with elastic flexible tethers are derived from Lagrange's equations. The controllability analysis indicates that both array resizing and spin-up are fully controllable by the reaction wheels and the tether motor, thereby saving thruster fuel consumption. Based upon this analysis, linear and nonlinear controllers have been successfully implemented on the tethered SPHERES testbed, and tested at the NASA MSFC's flat floor facility using two and three SPHERES configurations.", "date": "2006-06-27", "date_type": "published", "publisher": "Society of Photo-Optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "Art. No. 62680B", "id_number": "CaltechAUTHORS:20161122-120253690", "isbn": "0-8194-6333-7", "book_title": "Advances in Stellar Interferometry", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161122-120253690", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA", "grant_number": "NNG05CA09C" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Monnier-J-D", "name": { "family": "Monnier", "given": "John D." } }, { "id": "Sch\u00f6ller-M", "name": { "family": "Sch\u00f6ller", "given": "Markus" } }, { "id": "Danchi-W-C", "name": { "family": "Danchi", "given": "William C." } } ] }, "doi": "10.1117/12.670489", "primary_object": { "basename": "62680B_1.pdf", "url": "https://authors.library.caltech.edu/records/r3bx2-2rd03/files/62680B_1.pdf" }, "pub_year": "2006", "author_list": "Chung, Soon-Jo; Adams, Danielle; et el." }, { "id": "https://authors.library.caltech.edu/records/e600m-ebq78", "eprint_id": 41479, "eprint_status": "archive", "datestamp": "2023-08-19 17:30:34", "lastmod": "2024-01-13 06:04:17", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Moghaddam-A-N", "name": { "family": "Moghaddam", "given": "Abbas N." } }, { "id": "Forouhar-A-S", "name": { "family": "Forouhar", "given": "Arian" } }, { "id": "Liebling-M", "name": { "family": "Liebling", "given": "Michael" } }, { "id": "Tsai-H-J", "name": { "family": "Tsai", "given": "Huai-Jen" } }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "Morteza" } } ] }, "title": "Structure and function relationship of Zebrafish embryonic heart from confocal microscopy images", "ispublished": "unpub", "full_text_status": "public", "keywords": "cardiac mechanics, confocal microscopy, Embryonic heart, image-based biomechanical models, strain,\nstructure, function", "note": "\u00a9 2006 SPIE.\n\nPublished - Gharib_2006p614301.pdf
", "abstract": "Confocal microscopy enables us to track myocytes in the embryonic zebrafish heart. The Zeiss LSM 5 Live high speed\nconfocal microscope has been used to take optical sections (at 3 \u00b5m intervals and 151 frames per second) through a\nfluorescently labeled zebrafish heart at two developmental stages (26 and 34 hours post fertilization (hpf)). This data\nprovides unique information allowing us to conjecture on the morphology and biomechanics of the developing vertebrate\nheart. Nevertheless, the myocytes, whose positions could be determined in a reliable manner, were located sparsely and\nmostly in one side of the heart tube. This difficulty was overcome using computational methods, that give longitudinal,\nradial and circumferential displacements of the myocytes as well as their contractile behavior. Applied strain analysis\nhas shown that in the early embryonic heart tube, only the caudal region (near the in-flow) and another point in the\nmiddle of the tube can be active; the rest appears to be mostly passive. This statement is based on the delay between\nmajor strain and displacement which a material point experiences. Wave-like propagation of all three components of the\ndisplacement, especially in the circumferential direction, as well as the almost-periodic changes of the maximum strain\nsupport the hypothesis of helical muscle structure embedded in the tube. Changes of geometry in the embryonic heart\nafter several hours are used to verify speculations about the structure based on the earlier images and aforementioned\nmethods.", "date": "2006-03-13", "date_type": "published", "publisher": "International Society for Optical Engineering", "place_of_pub": "Bellingham, WA", "pagerange": "Art. No. 614301", "id_number": "CaltechAUTHORS:20130923-112227307", "isbn": "0-8194-6186-5", "book_title": "Medical Imaging 2006: Physiology, Function, and Structure from Medical Images", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130923-112227307", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Manduca-A", "name": { "family": "Manduca", "given": "Armando" } }, { "id": "Amini-A-A", "name": { "family": "Amini", "given": "Amir A." } } ] }, "doi": "10.1117/12.652779", "primary_object": { "basename": "Gharib_2006p614301.pdf", "url": "https://authors.library.caltech.edu/records/e600m-ebq78/files/Gharib_2006p614301.pdf" }, "pub_year": "2006", "author_list": "Moghaddam, Abbas N.; Forouhar, Arian; et el." }, { "id": "https://authors.library.caltech.edu/records/sx4xr-tgp20", "eprint_id": 21854, "eprint_status": "archive", "datestamp": "2023-08-19 17:08:48", "lastmod": "2023-10-23 15:26:19", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Avrahami-I", "name": { "family": "Avrahami", "given": "I." } }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "M." } } ] }, "title": "Effects of membrane stiffening on focal-adhesion bonding under steady and unsteady conditions", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2006 IEEE.\n\nIssue Date: 15-18 Jan. 2006; Date of Current Version: 26 March 2007.\n\nPublished - Avrabami2006p90002006_Bio-_Micro-_And_Nanosystems_Conference.pdf
", "abstract": "Platelets adhesion occurs at focal adhesions (FA), where cell-membrane receptors bind specifically to substrate proteins and couple to each other and to the cytoskeleton via various cellular proteins. Some of the reactions that follow the ligand-receptor binding at the FA may affect\nmechanical determinants of the cell-substrate attachment. The resulting molecular structure suggests that the cortex stiffens at the FA, which likely affects platelet adhesion. The present work explores that hypothesis using a numerical simulation of the 3D membrane flexible structure under steady and unsteady bond kinetic and detachment forces. The cortex is modeled as a shell anchored to the substrate by unevenly distributed adhesion forces and subjected to externally detachment forces. In the simulated models, the steady case address to a stabilized condition, when both the adhesion forces and the detachment forces are steady. In the unsteady case, however, some aspects of bond kinetics\nand unsteadiness in the external detachment forces are incorporated. The commercial finite-element package ADINA (Watertown, MA) is used to solve the 3D time-dependent structural equations in the model. The results show the effect of cortex stiffening at the focal adhesion sites on the membrane deformation for both the steady and unsteady cases. The consequent internal stresses are described and the effects of membrane stiffening on the bonding forces are compared for the different cases. In addition, the effect of uneven distribution of focal adhesion complexes on the cells' structural support is evaluated and the consequences on cell function and behaviors are discussed.", "date": "2006-01", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "85", "id_number": "CaltechAUTHORS:20110121-142834407", "isbn": "978-1-4244-0056-0", "book_title": "2006 Bio-, Micro- and Nanosystems Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110121-142834407", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "9487282", "name": "INSPEC Accession Number" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/BMN.2006.330889", "primary_object": { "basename": "Avrabami2006p90002006_Bio-_Micro-_And_Nanosystems_Conference.pdf", "url": "https://authors.library.caltech.edu/records/sx4xr-tgp20/files/Avrabami2006p90002006_Bio-_Micro-_And_Nanosystems_Conference.pdf" }, "pub_year": "2006", "author_list": "Avrahami, I. and Gharib, M." }, { "id": "https://authors.library.caltech.edu/records/p4fzg-can88", "eprint_id": 98317, "eprint_status": "archive", "datestamp": "2023-08-19 17:08:22", "lastmod": "2023-10-18 17:15:06", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Liu-C-T", "name": { "family": "Liu", "given": "C. T." } }, { "id": "Neviere-R", "name": { "family": "Neviere", "given": "R." } }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "G." }, "orcid": "0000-0002-2912-0001" } ] }, "title": "Crack Growth Behavior in a Highly Filled Elastomer", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2006 Springer.", "abstract": "An important engineering problem in structural design is evaluating its integrity and reliability. It is well known that structural strength may be degraded during its design life due to mechanical or chemical aging, or a combination of these two aging mechanisms. Depending on the structural design, material type, service loading, and environmental condition, the cause and degree of strength degradation due to the different aging mechanisms differs. One of the common causes of strength degradation is the result of damage and crack development in the structure. Therefore, to effectively use the material in structural applications one needs to understand the damage initiation and evolution processes, the effects of damage and crack development on the material's response, and the remaining strength and life of the structures.", "date": "2006", "date_type": "published", "publisher": "Springer", "place_of_pub": "Dordrecht", "pagerange": "1135-1136", "id_number": "CaltechAUTHORS:20190828-113605785", "isbn": "978-1-4020-4971-2", "book_title": "Fracture of Nano and Engineering Materials and Structures", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190828-113605785", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Gdoutos-E-E", "name": { "family": "Gdoutos", "given": "E. E." } } ] }, "doi": "10.1007/1-4020-4972-2_563", "pub_year": "2006", "author_list": "Liu, C. T.; Neviere, R.; et el." }, { "id": "https://authors.library.caltech.edu/records/1qwm8-btd82", "eprint_id": 23049, "eprint_status": "archive", "datestamp": "2023-08-22 04:46:55", "lastmod": "2024-01-13 05:13:17", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Faddy-J-M", "name": { "family": "Faddy", "given": "J. M." } }, { "id": "Pullin-D-I", "name": { "family": "Pullin", "given": "D. I." } } ] }, "title": "Evolution of vortex structures in a model of the turbulent trailing vortex", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "trailing vortices; axial flow; M&M vortex", "note": "\u00a9 2006 Springer.", "abstract": "We present results obtained from a direct numerical simulation for a model of incompressible trailing vortices consisting of an array of counter-rotating vortices and a superposed axial velocity in a doubly-periodic domain, infinite in the vertical direction. The Reynolds number based on vortex circulation is 1000. It is found that for suffciently strong axial flow, helical instability modes develop on each vortex. This leads to a decrease in the magnitude of the axial flow and subsequent relaminarization of each vortex. At later times, modes corresponding to the more slowly growing co-operative instability become dominant. These produce their own helical structures followed by the rapid growth of small scales, then vorticity cancellation and decay of the vortex array. In the presence of strong axial flow the helical structure persists and the vortices appear more resistant to the breakdown phenomena than for arrays with no axial flow.", "date": "2006", "date_type": "published", "publisher": "Springer", "place_of_pub": "Dordrecht", "pagerange": "259-264", "id_number": "CaltechAUTHORS:20110322-102528073", "isbn": "1-4020-4180-2", "book_title": "IUTAM Symposium on Elementary Vortices and Coherent Structures : Significance in Turbulence Dynamics", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110322-102528073", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Kida-Shigeo", "name": { "family": "Kida", "given": "Shigeo" } } ] }, "doi": "10.1007/1-4020-4181-0", "pub_year": "2006", "author_list": "Faddy, J. M. and Pullin, D. I." }, { "id": "https://authors.library.caltech.edu/records/1cnve-9xb11", "eprint_id": 22120, "eprint_status": "archive", "datestamp": "2023-08-19 16:54:09", "lastmod": "2024-01-13 00:09:40", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Liebling-M", "name": { "family": "Liebling", "given": "Michael" } }, { "id": "Vermot-J", "name": { "family": "Vermot", "given": "Julien" } }, { "id": "Forouhar-A-S", "name": { "family": "Forouhar", "given": "Arian S." } }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "Morteza" }, "orcid": "0000-0003-0754-4193" }, { "id": "Dickinson-Mary-E", "name": { "family": "Dickinson", "given": "Mary E." } }, { "id": "Fraser-S-E", "name": { "family": "Fraser", "given": "Scott E." }, "orcid": "0000-0002-5377-0223" } ] }, "title": "Nonuniform temporal alignment of slice sequences for four-dimensional imaging of cyclically deforming embryonic structures", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2006 IEEE. Issue Date: 6-9 April 2006; Date of Current Version: 08 May 2006. We thank Sean Megason, Le Trinh, and Chris Waters for help\nwith zebrafish preparation and advice on imaging techniques.\nM.L. would like to thank Michael Unser for helpful discussions\nand for sharing unpublished work on related topics.\n\nPublished - Liebling2006p89842007_4Th_Ieee_International_Symposium_On_Biomedical_Imaging_Macro_To_Nano_Vols_1-3.pdf
", "abstract": "The temporal alignment of nongated slice-sequences acquired\nat different axial positions in the living embryonic zebrafish\nheart permits the reconstruction of dynamic, three-dimensional\ndata. This approach overcomes the current acquisition-\nspeed limitation of confocal microscopes for real-time\nthree-dimensional imaging of fast processes. Current synchronization\nmethods align and uniformly scale the data in\ntime, but do not compensate for slight variations in the heart\nrhythm that occur within a heartbeat. Therefore, they impose\nconstraints on the admissible data quality. Here, we derive\na nonuniform registration procedure based on the minimization\nof the absolute value of the intensity difference between\nadjacent slice-sequence pairs. The method compensates for\ntemporal intra-sample variations and allows the processing of\na wider range of data to build functional, dynamic models of\nthe beating embryonic heart. We show reconstructions from\ndata acquired in living, fluorescent zebrafish embryos.", "date": "2006", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "1156-1159", "id_number": "CaltechAUTHORS:20110210-150606480", "isbn": "978-0-7803-9576-3", "book_title": "2006 3rd IEEE International Symposium on Biomedical Imaging: Macro to Nano", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110210-150606480", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "9054422", "name": "INSPEC Accession Number" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/ISBI.2006.1625128", "primary_object": { "basename": "Liebling2006p89842007_4Th_Ieee_International_Symposium_On_Biomedical_Imaging_Macro_To_Nano_Vols_1-3.pdf", "url": "https://authors.library.caltech.edu/records/1cnve-9xb11/files/Liebling2006p89842007_4Th_Ieee_International_Symposium_On_Biomedical_Imaging_Macro_To_Nano_Vols_1-3.pdf" }, "pub_year": "2006", "author_list": "Liebling, Michael; Vermot, Julien; et el." }, { "id": "https://authors.library.caltech.edu/records/v6y7r-45c96", "eprint_id": 99168, "eprint_status": "archive", "datestamp": "2023-08-19 17:08:28", "lastmod": "2023-10-18 17:55:24", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Mosler-J", "name": { "family": "Mosler", "given": "J." } }, { "id": "Ortiz-M", "name": { "family": "Ortiz", "given": "M." }, "orcid": "0000-0001-5877-4824" } ] }, "title": "Finite strain r-adaption based on a fully variational framework", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2006 Springer.", "abstract": "A novel r-adaptive finite element strategy based on a fully variational framework is presented. Provided the underlying physical problem is characterized by means of a minimization principle, the proposed method seeks, for a fixed number of nodes, for the best finite element interpolation depending on the nodal positions with respect to the deformed (x) as well as the undeformed (X) configuration, cf. [1]. The existence of a minimization problem does not represent a very strong restriction, since for many physical problems such as standard dissipative media an incremental potential can also be recast, cf. [2]. While minimizing the potential considered by fixing the nodes within the undeformed configuration corresponds to classical NEWTONian mechanics, a variation with respect to (X) is associated with ESHELBY mechanics, cf. [3]. However, in contrast to the simplicity of the concept, its numerical implementation is far away from being straightforward. According to [4], the resulting system of equations is highly singular and hence, standard optimization strategies cannot be applied. In this paper, a viscous regularization is used. This approach is designed to render the minimization problem well-posed while leaving its solutions unchanged. Obviously, relocating the nodes within the undeformed configuration by fixing the triangulation (the connectivity) may lead to strong topological constraints. As a consequence, an energy based re-meshing strategy is advocated. Contrary to classical mesh-improvement methods based on geometrical quality measures, the novel concepts identifies local energy minimizers. That is, the energy of the new triangulation is always lower than that of the initial discretization. The performance of the resulting finite element model is demonstrated by fully three-dimensional examples.", "date": "2006", "date_type": "published", "publisher": "Springer", "place_of_pub": "Dordrecht", "pagerange": "407", "id_number": "CaltechAUTHORS:20191008-153941494", "isbn": "978-1-4020-4994-1", "book_title": "III European Conference on Computational Mechanics - Solids, Structures and Coupled Problems in Engineering: Book of Abstracts", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191008-153941494", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Motasoares-C-A", "name": { "family": "Motasoares", "given": "C. A." } }, { "id": "Martins-J-A-C", "name": { "family": "Martins", "given": "J. A. C." } }, { "id": "Rodrigues-H-C", "name": { "family": "Rodrigues", "given": "H. C." } }, { "id": "Ambr\u00f3sio-J-A-C", "name": { "family": "Ambr\u00f3sio", "given": "Jorge A. C." } }, { "id": "Pina-C-A-B", "name": { "family": "Pina", "given": "C. A. B." } }, { "id": "Pereira-E-B-R", "name": { "family": "Pereira", "given": "E. B. R." } }, { "id": "Folgado-J", "name": { "family": "Folgado", "given": "J." } } ] }, "doi": "10.1007/1-4020-5370-3_407", "pub_year": "2006", "author_list": "Mosler, J. and Ortiz, M." }, { "id": "https://authors.library.caltech.edu/records/v4p33-8mc06", "eprint_id": 103793, "eprint_status": "archive", "datestamp": "2023-08-22 04:51:15", "lastmod": "2024-01-15 04:31:32", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "Hans G." }, "orcid": "0000-0002-4903-8419" } ] }, "title": "Hypersonic Real-Gas Effects on Transition", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Vibrational Excitation; Hypersonic Flow; AIAA Journal; Boundary Layer Transition; Stanton Number", "note": "\u00a9 2006 Springer. \n\nThe work described in this paper was supported by AFOSR Grants F49610-92-J-0110, F49620-93-1-0338, and F49620-98-1-0353.", "abstract": "Some of the results of an extensive research program into the effects on transition of the vibrational and chemical relaxation processes that occur in high-enthalpy flows are presented. Relaxation effects are found to influence transition significantly, with increases of the transition Reynolds number by up to a factor of five. The mechanism responsible for this transition delay is shown to be the damping of the acoustic second mode instability by relaxation processes. Transition is also found to be further delayed by up to a factor of two by suitable wall porosity.", "date": "2006", "date_type": "published", "publisher": "Springer", "place_of_pub": "Dordrecht", "pagerange": "335-344", "id_number": "CaltechAUTHORS:20200609-100252589", "isbn": "978-1-4020-4149-5", "book_title": "IUTAM Symposium on One Hundred Years of Boundary Layer Research", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200609-100252589", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "F49610-92-J-0110" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "F49620-93-1-0338" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "F49620-98-1-0353" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Meier-G-E-A", "name": { "family": "Meier", "given": "G. E. A." } }, { "id": "Sreenivasan-K-R", "name": { "family": "Sreenivasan", "given": "K. R." } }, { "id": "Heinemann-H-J", "name": { "family": "Heinemann", "given": "H.-J." } } ] }, "doi": "10.1007/978-1-4020-4150-1_32", "pub_year": "2006", "author_list": "Hornung, Hans G." }, { "id": "https://authors.library.caltech.edu/records/pjwqf-qv757", "eprint_id": 103792, "eprint_status": "archive", "datestamp": "2023-08-22 04:51:07", "lastmod": "2023-10-20 16:43:12", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Arias-I", "name": { "family": "Arias", "given": "Irene" } }, { "id": "Knap-J", "name": { "family": "Knap", "given": "Jaroslaw" } }, { "id": "Chalivendra-V-B", "name": { "family": "Chalivendra", "given": "Vijaya B." } }, { "id": "Hong-Soonsung", "name": { "family": "Hong", "given": "Soonsung" } }, { "id": "Ortiz-M", "name": { "family": "Ortiz", "given": "Michael" }, "orcid": "0000-0001-5877-4824" }, { "id": "Rosakis-A-J", "name": { "family": "Rosakis", "given": "Ares J." }, "orcid": "0000-0003-0559-0794" } ] }, "title": "Validation of large scale simulations of dynamic fracture", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Dynamic Fracture; Cohesive Zone Model; Cohesive Element; Large Scale Simulation; Weak Plane", "note": "\u00a9 2006 Springer.", "abstract": "A novel integrated approach is developed for a systematic validation of large-scale finite element simulations on dynamic crack propagations along a weak plane [1]. A set of well-controlled experimental scheme is specifically designed to provide accurate input data for the numerical simulations as well as to provide metrics for quantitative comparisons between experimental and numerical results. Dynamic photoelasticity with high-speed photography is used to capture experimental records of dynamic crack propagations along a weak plane and to provide the crack propagation history. In the dynamic experiments, a modified Hopkinson bar setup with a notch-face loading configuration is used to obtain controlled loading conditions for the dynamic fracture problem. Also an inverse-problem approach of cohesive zone model is employed to obtain a realistic cohesive law, i.e. a traction-separation law, of the weak plane, from independently measured crack-tip deformation fields using speckle interferometry technique. The experimentally collected data, the loading conditions and the cohesive law, are considered as input for the finite element simulations [2]. We employ finite-deformation cohesive elements to account for crack initiation and growth in bulk finite-element discretizations of the experimental sample. As it is well know, the cohesive elements introduce an additional material-dependent length-scale into the finite element model. The demand of accurately resolving this length-scale by the finite-element discretization, as required for truly mesh-independent results, may often lead to discretizations containing several millions of elements. We therefore resort to massively parallel computing. \n\nA comparison of the metrics from the numerical simulations with those from the experimental measurements is performed to validate the large-scale simulations. The numerical results show good agreements with the experimental results, leading to a successful validation of the large scale simulations of the dynamic crack propagations along the weak plane.", "date": "2006", "date_type": "published", "publisher": "Springer", "place_of_pub": "Dordrecht", "pagerange": "252-252", "id_number": "CaltechAUTHORS:20200609-095317554", "isbn": "978-1-4020-4994-1", "book_title": "III European Conference on Computational Mechanics - Solids, Structures and Coupled Problems in Engineering: Book of Abstracts", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200609-095317554", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Motasoares-C-A", "name": { "family": "Motasoares", "given": "C. A." } }, { "id": "Martins-J-A-C", "name": { "family": "Martins", "given": "J. A. C." } }, { "id": "Rodrigues-H-C", "name": { "family": "Rodrigues", "given": "H. C." } }, { "id": "Ambr\u00f3sio-J-A-C", "name": { "family": "Ambr\u00f3sio", "given": "Jorge A. C." } }, { "id": "Pina-C-A-B", "name": { "family": "Pina", "given": "C. A. B." } }, { "id": "Motasoares-C-M", "name": { "family": "Motasoares", "given": "C. M." } }, { "id": "Pereira-E-B-R", "name": { "family": "Pereira", "given": "E. B. R." } }, { "id": "Folgado-J", "name": { "family": "Folgado", "given": "J." } } ] }, "doi": "10.1007/1-4020-5370-3_252", "pub_year": "2006", "author_list": "Arias, Irene; Knap, Jaroslaw; et el." }, { "id": "https://authors.library.caltech.edu/records/wppwn-yq492", "eprint_id": 98077, "eprint_status": "archive", "datestamp": "2023-08-22 04:50:46", "lastmod": "2023-10-18 17:01:31", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Arias-I", "name": { "family": "Arias", "given": "Irene" } }, { "id": "Serebrinsky-S", "name": { "family": "Serebrinsky", "given": "Santiago" } }, { "id": "Ortiz-M", "name": { "family": "Ortiz", "given": "Michael" }, "orcid": "0000-0001-5877-4824" } ] }, "title": "Cohesive Model of Electromechanical Fatigue for Ferroelectric Materials and Structures", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Fatigue Crack; Fatigue Life; Ferroelectric Material; Switchable Polarization; Cohesive Model", "note": "\u00a9 2006 Springer.", "abstract": "Ferroelectric materials are extensively used in a variety of sensor and actuator applications, where the non-linear coupling between mechanical and electrical fields are of primary interest. They are also a promising set of materials for improved dynamic as well as non-volatile memory devices, where only the electrical properties are directly exploited. However, ferroelectrics are brittle, and their low fracture toughness (in the order of 1MPam1/2) makes them susceptible to cracking. In addition, ferroelectric materials exhibit electrical fatigue (loss of switchable polarization) under cyclic electrical loading and, due to the strong electro-mechanical coupling, sometimes mechanical fatigue as well. Conversely, the propagation of fatigue cracks hinders the performance of the devices and raises serious reliability concerns.\n\nDespite recent experimental and modelling advances, the precise nature of the interactions between fracture, deformation and defect structures underlying ferroelectric fatigue is in need of further elucidation, and a physics-based multiscale model enabling the prediction of the fatigue life of ferroelectric devices is yet to emerge. Therefore, there remains a need for phenomenological and empirical models that can be experimentally validated and used in engineering design.\n\nWe present a model of electro-mechanical ferroelectric fatigue based on the postulate of a ferroelectric cohesive law that: couples mechanical displacement and electric-potential discontinuity to mechanical tractions and surface-charge density; and exhibits a monotonic envelope and loading-unloading hysteresis [1]. The model is applicable whenever the changes in properties leading to fatigue are localized in one or more planar-like regions, modelled by the cohesive surfaces. We validate the model against experimental data for a simple test configuration consisting of an infinite slab acted upon by an oscillatory voltage differential across the slab and otherwise stress free. The model captures salient features of the experimental record including: the existence of a threshold nominal field for the onset of fatigue; the dependence of the threshold on the applied-field frequency; the dependence of fatigue life on the amplitude of the nominal field; and the dependence of the coercive field on the size of the component, or size effect. Our results, although not conclusive, indicate that planar-like regions affected by cycling may lead to the observed fatigue in tetragonal PZT.", "date": "2006", "date_type": "published", "publisher": "Springer", "place_of_pub": "Dordrecht", "pagerange": "158", "id_number": "CaltechAUTHORS:20190821-105957679", "isbn": "978-1-4020-4994-1", "book_title": "III European Conference on Computational Mechanics. Solids, Structures and Coupled Problems in Engineering: Book of Abstracts", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190821-105957679", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Motasoares-C-A", "name": { "family": "Motasoares", "given": "C. A." } }, { "id": "Martins-J-A-C", "name": { "family": "Martins", "given": "J. A. C." } }, { "id": "Rodrigues-H-C", "name": { "family": "Rodrigues", "given": "H. C." } }, { "id": "Ambr\u00f3sio-J-A-C", "name": { "family": "Ambr\u00f3sio", "given": "Jorge A. C." } }, { "id": "Pina-C-A-B", "name": { "family": "Pina", "given": "C. A. B." } }, { "id": "Motasoares-C-M", "name": { "family": "Motasoares", "given": "C. M." } }, { "id": "Pereira-E-B-R", "name": { "family": "Pereira", "given": "E. B. R." } }, { "id": "Folgado-J", "name": { "family": "Folgado", "given": "J." } } ] }, "doi": "10.1007/1-4020-5370-3_158", "pub_year": "2006", "author_list": "Arias, Irene; Serebrinsky, Santiago; et el." }, { "id": "https://authors.library.caltech.edu/records/81kx6-q6g97", "eprint_id": 101703, "eprint_status": "archive", "datestamp": "2023-08-22 04:41:30", "lastmod": "2024-01-14 22:08:20", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Leonard-A", "name": { "family": "Leonard", "given": "A." } } ] }, "title": "Interaction of localised packets of vorticity with turbulence", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Lyapunov Exponent; Vortex Ring; Vortex Tube; Inertial Range; Chaotic Advection", "note": "\u00a9 2002 Kluwer Academic Publishers.", "abstract": "The evolution of initially weak structures of vorticity as they evolve in an incompressible turbulent flow is investigated. Such objects are candidates for important structures in the inertial range and in the dissipation range of scales. As these structures are strained by the flow, fine-scales of vorticity are produced along the direction of maximum compression with a consequent flow of energy to the high wavenumbers. It is shown that, under certain circumstances, the self-energy spectrum of such a structure may be time-averaged, producing a fractional power law. The exponent of the power law depends on the ratio of the first two Lyapunov exponents of the strain tensor.", "date": "2005-12-16", "date_type": "published", "publisher": "Kluwer Academic Publishers", "place_of_pub": "Dordrecht", "pagerange": "201-210", "id_number": "CaltechAUTHORS:20200304-094728369", "isbn": "978-1-4020-0980-8", "book_title": "Tubes, Sheets and Singularities in Fluid Dynamics", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200304-094728369", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Bajer-K", "name": { "family": "Bajer", "given": "K." } }, { "id": "Moffatt-H-K", "name": { "family": "Moffatt", "given": "H. K." } } ] }, "doi": "10.1007/0-306-48420-x_27", "pub_year": "2005", "author_list": "Leonard, A." }, { "id": "https://authors.library.caltech.edu/records/p87b4-j0k29", "eprint_id": 98297, "eprint_status": "archive", "datestamp": "2023-08-22 04:41:21", "lastmod": "2024-01-14 21:55:11", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Pullin-D-I", "name": { "family": "Pullin", "given": "D. I." } } ] }, "title": "Vortex tubes, spirals, and large-eddy simulation of turbulence", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Axial Velocity; Rotation Number; Suction Side; Vortex Tube; Passive Scalar", "note": "\u00a9 Kluwer Academic Publishers 2002. \n\nThis work was supported in part by the National Science Foundation under Grant CTS-9634222. Useful discussions with P. Dimotakis, T.S. Lundgren and T. Voelkl are gratefully acknowledged.", "abstract": "Progress in the quantitative modelling of turbulence using vortex-based models of the fine scales is reviewed. Recent work on the calculation of the spectrum of a passive scalar convecting and diffusing within a stretched-spiral vortex is briefly described. This is followed by a discussion of the application of ideas from the study of the vortex structure of the small scales of turbulence to the development of subgrid models for the large-eddy simulation (LES) of turbulent flows at large Reynolds numbers. Examples are given including the LES of rotating and non-rotating plane channel flow and of the mixing of a passive scalar by forced isotropic turbulence.", "date": "2005-12-16", "date_type": "published", "publisher": "Kluwer Academic Publishers", "place_of_pub": "Dordrecht", "pagerange": "171-180", "id_number": "CaltechAUTHORS:20190828-102317519", "isbn": "1402009801", "book_title": "Tubes, Sheets and Singularities in Fluid Dynamics", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190828-102317519", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "CTS-9634222" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Bajer-K", "name": { "family": "Bajer", "given": "K." } }, { "id": "Moffatt-H-K", "name": { "family": "Moffatt", "given": "H. K." } } ] }, "doi": "10.1007/0-306-48420-x_24", "pub_year": "2005", "author_list": "Pullin, D. I." }, { "id": "https://authors.library.caltech.edu/records/96td5-myt03", "eprint_id": 72245, "eprint_status": "archive", "datestamp": "2023-08-19 16:14:58", "lastmod": "2024-01-13 20:20:42", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Kong-Edmund-M", "name": { "family": "Kong", "given": "Edmund M." } }, { "id": "Miller-D-W", "name": { "family": "Miller", "given": "David W." }, "orcid": "0000-0001-6099-0614" } ] }, "title": "SPHERES Tethered Formation Flight Testbed: Application to NASA's SPECS Mission", "ispublished": "unpub", "full_text_status": "public", "keywords": "stellar interferometer, space tether, formation flight", "note": "\u00a9 2005 International Society for Optical Engineering. \n\nThe authors would like to gratefully acknowledge NASA for both financial and technical support for the MITSSL and PSI SPHERES Tether program. This work has been sponsored under NASA Phase II SBIR contact (Contract No.: NNG05CA09C).\n\nPublished - 58990L_1.pdf
", "abstract": "This paper elaborates on theory and experiment of the formation flight control for the future space-borne tethered interferometers. The nonlinear equations of multi-vehicle tethered spacecraft system are derived by Lagrange equations and decoupling method. The preliminary analysis predicts unstable dynamics depending on the direction of the tether motor. The controllability analysis indicates that both array resizing and spin-up are fully controllable only by the reaction wheels and the tether motor, thereby eliminating the need for thrusters. Linear and nonlinear decentralized control techniques have been implemented into the tethered SPHERES testbed, and tested at the NASA MSFC's flat floor facility using two and three SPHERES configurations. The nonlinear control using feedback linearization technique performed successfully in both two SPHERES in-line configuration and three triangular configuration while varying the tether length. The relative metrology system, using the ultra sound metrology system and the inertial sensors as well as the decentralized nonlinear estimator, is developed to provide necessary state information.", "date": "2005-08-24", "date_type": "published", "publisher": "Society of Photo-Optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "Art. No. 58990L", "id_number": "CaltechAUTHORS:20161122-111732319", "isbn": "9780819459046", "book_title": "UV/Optical/IR Space Telescopes: Innovative Technologies and Concepts II", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161122-111732319", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA", "grant_number": "NNG05CA09C" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "MacEwen-H-A", "name": { "family": "MacEwen", "given": "Howard A." } } ] }, "doi": "10.1117/12.614643", "primary_object": { "basename": "58990L_1.pdf", "url": "https://authors.library.caltech.edu/records/96td5-myt03/files/58990L_1.pdf" }, "pub_year": "2005", "author_list": "Chung, Soon-Jo; Kong, Edmund M.; et el." }, { "id": "https://authors.library.caltech.edu/records/fcr63-shx42", "eprint_id": 50240, "eprint_status": "archive", "datestamp": "2023-08-19 16:07:12", "lastmod": "2023-10-17 22:52:12", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Austin-J-M", "name": { "family": "Austin", "given": "Joanna" } } ] }, "title": "Pressure-driven wave propagation in mm-scale channels", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2005 American Physical Society.\n\nDate submitted: 27 Jul 2005.\n\nAbstract ID: BAPS.2005.DFD.HM.3\n\nPublished - MWS_DFD05-2005-000195.pdf
", "abstract": "Miniaturized analysis systems, which may potentially revolutionize detection of air-borne biological or chemical agents through increased portability and real time response, also present exciting\nfundamental challenges. Development of integrated total analysis systems will depend on optimizing the interaction of multiple components such as valves, injectors,\npumps, and channels. In pressure-driven systems, such components may produce\nfinite amplitude waves and wave attenuation may then be a key design factor in optimizing both devices that operate on steady-state assumptions and devices where\nunsteadiness is cultivated, for example mixers. A fundamental experimental investigation of wave propagation as a function of the channel size was performed.\nA shock wave is transmitted into mm-scale channels to achieve a well-characterized\ninitial condition. Wave attenuation and structure information is obtained from time-of-arrival data and pressure histories along the channel. Experimental results are\ncompared with models developed for the analogous flow regime of wave propagation\nthrough macroscale channels in low pressure environments.", "date": "2005-07-27", "date_type": "published", "publisher": "American Physical Society", "id_number": "CaltechAUTHORS:20141007-135422657", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141007-135422657", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "primary_object": { "basename": "MWS_DFD05-2005-000195.pdf", "url": "https://authors.library.caltech.edu/records/fcr63-shx42/files/MWS_DFD05-2005-000195.pdf" }, "pub_year": "2005", "author_list": "Austin, Joanna" }, { "id": "https://authors.library.caltech.edu/records/j2828-5k923", "eprint_id": 4967, "eprint_status": "archive", "datestamp": "2023-08-22 03:53:33", "lastmod": "2023-10-16 18:01:45", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Valentino-J-P", "name": { "family": "Valentino", "given": "J. P." } }, { "id": "Troian-S-M", "name": { "family": "Troian", "given": "S. M." }, "orcid": "0000-0003-1224-6377" }, { "id": "Wagner-S", "name": { "family": "Wagner", "given": "S." } } ] }, "title": "Microfluidic detection and analysis by integration of evanescent wave sensing with thermocapillary actuation", "ispublished": "unpub", "full_text_status": "public", "keywords": "biosensors; micromanipulators; enzymatic hydrolysis; evanescent wave sensing; microfluidic analysis; microheater array; planar thin film waveguide; reaction kinetics; thermocapillary actuation; thermocapillary manipulation", "note": "This work was funded by the NASA Microgravity Fluid Physics Program and the US Army TACOM-ARDEC. JPV wishes to thank Dr. P. K. Tien of Bell Labs for helpful discussions. SMT gratefully acknowledges the Moore Distinguished Scholar Program at Caltech, where she is currently on leave, for the generous hospitality and financial support extended during her stay.", "abstract": "An integrated system capable of microfluidic actuation, detection and sensing is described which combines evanescent wave sensing with thermocapillary manipulation. Liquid droplets or streams transported across the beam path of a planar thin film waveguide, which encapsulates the microheater array, induce attenuation of the propagating waveguide modes. The attenuated signal is used to monitor droplet location, dye concentration in aqueous solutions and reaction kinetics for enzymatic hydrolysis of the sugar X-galactose by beta-galactosidase.", "date": "2005-07-05", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Los Alamitos, CA", "pagerange": "730-733", "id_number": "CaltechAUTHORS:VALmems05", "isbn": "0-7803-8732-5", "book_title": "Proceedings of the 18th IEEE International Conference on Micro Electro Mechanical Systems (MEMS 2005), Miami, FL, 30 Jan.-3 Feb. 2005", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:VALmems05", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/MEMSYS.2005.1454033", "primary_object": { "basename": "VALmems05.pdf", "url": "https://authors.library.caltech.edu/records/j2828-5k923/files/VALmems05.pdf" }, "pub_year": "2005", "author_list": "Valentino, J. P.; Troian, S. M.; et el." }, { "id": "https://authors.library.caltech.edu/records/c09tn-xj705", "eprint_id": 50112, "eprint_status": "archive", "datestamp": "2023-08-19 15:12:06", "lastmod": "2023-10-17 22:31:22", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Austin-J-M", "name": { "family": "Austin", "given": "J. M." } }, { "id": "Pintgen-F", "name": { "family": "Pintgen", "given": "F." } }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "J. E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "Lead Shock Oscillation and Decoupling in Propagating Detonations", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2005 by California Institute of Technology. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.\n\nAIAA 2005-1170.\n\nPublished - 385525.pdf
", "abstract": "Experimental images of propagating detonation\nwaves provide lead shock velocity measurements\nthrough the cell cycle. We examine the issue of local\ndecoupling of the shock and reaction front using these\ndata. In highly unstable mixtures with high reduced\nactivation energy, experimental images and analysis\nsuggest that local decoupling occurs at the end of the\ncell cycle. Regions of high fluorescence intensity are\nobserved in shear layers in apparently decoupled portions\nof the detonation front.", "date": "2005-01", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "id_number": "CaltechAUTHORS:20140930-081843737", "isbn": "978-1-62410-064-2", "book_title": "43rd AIAA Aerospace Sciences Meeting and Exhibit", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140930-081843737", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2005-1170", "primary_object": { "basename": "385525.pdf", "url": "https://authors.library.caltech.edu/records/c09tn-xj705/files/385525.pdf" }, "pub_year": "2005", "author_list": "Austin, J. M.; Pintgen, F.; et el." }, { "id": "https://authors.library.caltech.edu/records/z6713-sae26", "eprint_id": 103809, "eprint_status": "archive", "datestamp": "2023-08-22 02:57:58", "lastmod": "2023-10-20 16:44:16", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chao-T", "name": { "family": "Chao", "given": "T." } }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "J. E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "Detonation loading of tubes in the modified shear wave speed regime", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Wave Speed; Detonation Wave; Transverse Shear; Critical Speed; Detonation Front", "note": "\u00a9 2005 Tsinghua University Press and Springer-Verlag Berlin Heidelberg. \n\nWe thank Prof. W. G. Knauss and Prof. G. Ravichandran for their advice and technical assistance in this project. This work was supported by the Center for Simulation of Dynamic Response of Materials at Caltech, sponsored by the US Department of Energy.", "abstract": "We performed experiments and numerical simulations on a thin-wall aluminum tube with internal gaseous detonation loading in the modified shear wave speed regime. Strain gauges were used to determine the time-dependent hoop strain on the surface of the tube. The experimental results were compared with analytical models and numerical simulations with explicit finite element computation treating the detonation as a traveling load. Hoop strain amplification factors (defined as the ratio of the dynamic strain to the equivalent static strain) close to two were obtained both in the present experiments and simulations. No resonance phenomena in the hoop strain were found in either experiments or simulations. Computations reveal the existence of a resonance in the shear strain.", "date": "2005", "date_type": "published", "publisher": "Springer", "place_of_pub": "Berlin", "pagerange": "865-870", "id_number": "CaltechAUTHORS:20200610-075535582", "isbn": "978-3-540-22497-6", "book_title": "Shock Waves", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200610-075535582", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech" }, { "agency": "Department of Energy (DOE)" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Jiang-Z", "name": { "family": "Jiang", "given": "Z." } } ] }, "doi": "10.1007/978-3-540-27009-6_131", "pub_year": "2005", "author_list": "Chao, T. and Shepherd, J. E." }, { "id": "https://authors.library.caltech.edu/records/2f4dp-fex64", "eprint_id": 101700, "eprint_status": "archive", "datestamp": "2023-08-22 02:57:18", "lastmod": "2023-10-19 22:57:46", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "J. E." }, "orcid": "0000-0003-3181-9310" }, { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "H. G." }, "orcid": "0000-0002-4903-8419" } ] }, "title": "Blast Waves and Explosions Sound generation by explosive decompression of an airplane", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Shock Tube; Blast Wave; Sound Generation; Sonic Boom; Lead Shock Wave", "note": "\u00a9 2005 Tsinghua University Press and Springer-Verlag Berlin Heidelberg.", "abstract": "We examine sound generation by the explosive decompression of a pressurized airplane in flight. The near-field is numerically computed by assuming the sudden removal of an axial section of an idealized, streamlined, cylindrical fuselage with an external flow simulating flight. After an initial transient period, we find a nearly circular blast wave with a leading shock strength that is highest in the direction of motion and decreasing rapidly as the observer moves to the rear of the airplane. Geometric acoustics (ray tracing) is used to estimate the attenuation of the wave as it propagates through a model atmosphere to observers on the ground. The audibility of the event is examined in the case of the TWA 800 accident and compared to previous analyses.", "date": "2005", "date_type": "published", "publisher": "Springer", "place_of_pub": "Berlin", "pagerange": "973-978", "id_number": "CaltechAUTHORS:20200304-093102338", "isbn": "978-3-540-22497-6", "book_title": "Shock Waves", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200304-093102338", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Jiang-Z", "name": { "family": "Jiang", "given": "Z." } } ] }, "doi": "10.1007/978-3-540-27009-6_148", "pub_year": "2005", "author_list": "Shepherd, J. E. and Hornung, H. G." }, { "id": "https://authors.library.caltech.edu/records/66yvj-c4w90", "eprint_id": 101704, "eprint_status": "archive", "datestamp": "2023-08-22 02:57:26", "lastmod": "2023-10-19 22:57:59", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hung-Patrick-Hin-Fun", "name": { "family": "Hung", "given": "P." } }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "J. E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "Initiation of stabilized detonations by projectiles", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Detonation Wave; Critical Radius; Detonation Initiation; Shock Curvature; Transverse Detonation Wave", "note": "\u00a9 2005 Tsinghua University Press and Springer-Verlag Berlin Heidelberg. \n\nThis research was supported by DOE-ASCI-ASAP.", "abstract": "A high-speed projectile in combustible gas can initiate and stabilize a detonation wave under suitable conditions [1]. In this paper, numerical simulations of projectile induced detonation waves are presented. Using a one-step irreversible reaction model, the transition from shock-induced combustion to stabilized oblique detonation is observed via numerical simulations. An analysis of this transition by means of the critical decay-rate model, which considers a balance between energy-release due to reaction, and quenching due to shock-curvature, is presented.", "date": "2005", "date_type": "published", "publisher": "Springer", "place_of_pub": "Berlin", "pagerange": "769-774", "id_number": "CaltechAUTHORS:20200304-095554599", "isbn": "978-3-540-22497-6", "book_title": "Shock Waves", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200304-095554599", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Department of Energy (DOE)" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Jiang-Z", "name": { "family": "Jiang", "given": "Z." } } ] }, "doi": "10.1007/978-3-540-27009-6_115", "pub_year": "2005", "author_list": "Hung, P. and Shepherd, J. E." }, { "id": "https://authors.library.caltech.edu/records/t32vm-5de38", "eprint_id": 92295, "eprint_status": "archive", "datestamp": "2023-08-19 14:19:27", "lastmod": "2024-01-14 21:26:39", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Pottebaum-T-S", "name": { "family": "Pottebaum", "given": "Tait S." } }, { "id": "MacMartin-D-G", "name": { "family": "MacMynowski", "given": "Douglas G." }, "orcid": "0000-0003-1987-9417" } ] }, "title": "Wind tunnel testing of a generic telescope enclosure", "ispublished": "unpub", "full_text_status": "public", "keywords": "Extremely-Large-Telescopes, Wind-buffeting, wind tunnel, DPIV", "note": "\u00a9 2004 Society of Photo-optical Instrumentation Engineers (SPIE).\n\nThe Thirty Meter Telescope (TMT) Project is a partnership of the Association of Universities for Research in\nAstronomy (AURA), the Association of Canadian Universities for Research in Astronomy (ACURA), the California\nInstitute of Technology and the University of California. The partners gratefully acknowledge the support of the\nGordon and Betty Moore Foundation, the US National Science Foundation, the National Research Council of Canada,\nthe Natural Sciences and Engineering Research Council of Canada, and the Gemini Partnership.\n\nMory Gharib (Caltech) provided substantial guidance and technical expertise in the design of this experiment and the\napplication of the DPIV technique. The Lucas AWT staff (Christopher Krok and Jerry Landry) supplied technical\nassistance in the areas of model construction, flow visualization, troubleshooting and test documentation. Joeleff\nFitzsimmions (HIA) and Konstantinos Vogiatzis (AURA NIO) also provided troubleshooting assistance and consulted\non the selection of test conditions.\n\nPublished - 270.pdf
", "abstract": "The design of future large optical telescopes must take into account the wind-induced buffeting of the telescope structure caused by large-scale flow structures and turbulence inside the dome. However, estimating the resulting degradation in image quality is difficult due to our relatively poor understanding of the flow inside the dome. Data has been collected in a scaled wind-tunnel test of a telescope enclosure to understand the flow-field around the region near the dome opening where the secondary mirror and supporting structure would be subjected to wind loads. Digital particle image velocimetry (DPIV) data was collected in a vertical plane near the dome opening to obtain mean velocity and fluctuation kinetic energy. In addition, hotwire data was collected along the telescope axis to obtain temporal spectra of the velocity, and flow visualization was used to determine the general flow patterns. In addition to its direct use in telescope modeling and design, this data is of particular value in validation of computational fluid dynamic (CFD) analyses, so that CFD can be used with confidence in future design work.", "date": "2004-09-29", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "270-281", "id_number": "CaltechAUTHORS:20190115-145634275", "isbn": "9780819454270", "book_title": "Astronomical Structures and Mechanisms Technology", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190115-145634275", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Association of Universities for Research in Astronomy (AURA)" }, { "agency": "Association of Canadian Universities for Research in Astronomy (ACURA)" }, { "agency": "Caltech" }, { "agency": "University of California" }, { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "NSF" }, { "agency": "National Research Council of Canada" }, { "agency": "Natural Sciences and Engineering Research Council of Canada (NSERC)" }, { "agency": "Gemini Partnership" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Thirty-Meter-Telescope" } ] }, "contributors": { "items": [ { "id": "Antebi-J", "name": { "family": "Antebi", "given": "Joseph" } }, { "id": "Lemke-D", "name": { "family": "Lemke", "given": "Dietrich" } } ] }, "doi": "10.1117/12.550798", "primary_object": { "basename": "270.pdf", "url": "https://authors.library.caltech.edu/records/t32vm-5de38/files/270.pdf" }, "pub_year": "2004", "author_list": "Pottebaum, Tait S. and MacMynowski, Douglas G." }, { "id": "https://authors.library.caltech.edu/records/cxrpz-68x31", "eprint_id": 72202, "eprint_status": "archive", "datestamp": "2023-08-19 14:15:47", "lastmod": "2024-01-13 20:20:38", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "LoBosco-D-M", "name": { "family": "LoBosco", "given": "David M." } }, { "id": "Blaurock-C", "name": { "family": "Blaurock", "given": "Carl" } }, { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Miller-D-W", "name": { "family": "Miller", "given": "David W." }, "orcid": "0000-0001-6099-0614" } ] }, "title": "Integrated modeling of optical performance for the Terrestrial Planet Finder structurally connected interferometer", "ispublished": "unpub", "full_text_status": "public", "keywords": "Integrated modeling, TPF, structural dynamics, controls, optical performance, disturbances, interferometer, structurally connected", "note": "\u00a9 2004 SPIE International Society for Optical Engineering. \n\nThis research was performed for the Jet Propulsion Laboratory under JPL Contract #1250253 (TPF Interferometer Trades and Model Development) with Technical/Scientific Officers Dr. Curt Henry and Dr. Brent Ware, and JPL Contract #1255406 (Model Verification) with Technical/Scientific Officer Dr. Marie Levine-West. Ms. Sharon-Leah Brown served as MIT Fiscal Officer for both contracts.\n\nPublished - 278_1.pdf
", "abstract": "The Terrestrial Planet Finder (TPF) mission, to be launched in 2014 as a part of NASA's Origins Program, will search for Earth-like planets orbiting other stars. One main concept under study is a structurally connected interferometer. Integrated modeling of all aspects of the flight system is necessary to ensure that the stringent dynamic stability requirements imposed by the mission are met. The MIT Space Systems Laboratory has developed a suite of analysis tools known as DOCS (Disturbances Optics Controls Structures) that provides a MATLAB environment for managing integrated models and performing analysis and design optimization. DOCS provides a framework for identifying critical subsystem design parameters and efficiently computing system performance as a function of subsystem design. Additionally, the gradients of the performance outputs with respect to design variables can be analytically computed and used for automated exploration and optimization of the design space. The TPF integrated model consists of a structural finite element model, optical performance model, reaction wheel isolation stage, and attitude/optical control systems. The integrated model is expandable and upgradeable due to the modularity of the state-space subsystem models. Optical performance under reaction wheel disturbances is computed, and the effects of changing design parameters are explored. The results identify redesign options that meet performance requirements with improved margins, reduced cost and minimized risk.", "date": "2004-09-16", "date_type": "published", "publisher": "Society of Photo-Optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "278-289", "id_number": "CaltechAUTHORS:20161121-130021663", "isbn": "0-8194-5429-X", "book_title": "Modeling and Systems Engineering for Astronomy", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161121-130021663", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "JPL", "grant_number": "1250253" }, { "agency": "JPL", "grant_number": "1255406" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Craig-S-C", "name": { "family": "Craig", "given": "Simon C." } }, { "id": "Cullum-M-J", "name": { "family": "Cullum", "given": "Martin J." } } ] }, "doi": "10.1117/12.550929", "primary_object": { "basename": "278_1.pdf", "url": "https://authors.library.caltech.edu/records/cxrpz-68x31/files/278_1.pdf" }, "pub_year": "2004", "author_list": "LoBosco, David M.; Blaurock, Carl; et el." }, { "id": "https://authors.library.caltech.edu/records/1sa5x-sbd61", "eprint_id": 24981, "eprint_status": "archive", "datestamp": "2023-08-22 02:21:32", "lastmod": "2024-01-13 05:20:51", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kheradvar-A", "name": { "family": "Kheradvar", "given": "A." } }, { "id": "Gorman-R-C", "name": { "family": "Gorman", "given": "R. C." } }, { "id": "Gorman-J-H-III", "name": { "family": "Gorman", "given": "J. H., III" } }, { "id": "Zeeshan-A", "name": { "family": "Zeeshan", "given": "A." } }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "M." } } ] }, "title": "Evaluation of isovolumic relaxation phase in the process of ventricular remodeling following myocardial infarction", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "isovolumic relaxation; pressure drop time constant; twisting; ventricular remodeling", "note": "\u00a9 2004 IEEE.\nIssue Date: 1-5 Sept. 2004.\nDate of Current Version: 14 March 2005.", "abstract": "The course of cardiac remodeling after an acute\ncardiac MI, might affect the orientation of the cardiac muscle fibers as well as their contraction behavior. This may result in alteration of the untwisting during isovolumic relaxation phase, which might have effects on rapid early filling phase. In the present article, the variation of the time constant of isovolumic pressure drop (\u03c4) has been studied during the course of cardiac remodeling after different types of induced myocardial infarction (MI) in sheep. The results for each group show different patterns of change in \u03c4. The normalized \u03c4\ncurve in all three groups of anteroapical, anterobasal and\nposterobasal MI group show a rise 30 minutes after infarction. Two weeks later, the pressure drop constants decline to a lower level than baseline and by eight weeks after infarction, the time constant reached around the baseline level.", "date": "2004-09", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "3654-3657", "id_number": "CaltechAUTHORS:20110822-140411786", "isbn": "0-7803-8439-3", "book_title": "EMBC 2004 : 26th Annual International Conference of the IEEE Engineering in Medicine and Biology Society", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110822-140411786", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/IEMBS.2004.1404027", "pub_year": "2004", "author_list": "Kheradvar, A.; Gorman, R. C.; et el." }, { "id": "https://authors.library.caltech.edu/records/a5jv7-1rs11", "eprint_id": 24989, "eprint_status": "archive", "datestamp": "2023-08-19 14:09:22", "lastmod": "2024-01-13 05:22:12", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Forouhar-A-S", "name": { "family": "Forouhar", "given": "A. S." } }, { "id": "Hove-J-R", "name": { "family": "Hove", "given": "J. R." } }, { "id": "Calvert-C", "name": { "family": "Calvert", "given": "C." } }, { "id": "Flores-J", "name": { "family": "Flores", "given": "J." } }, { "id": "Jadvar-H", "name": { "family": "Jadvar", "given": "H." } }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "M." } } ] }, "title": "Electrocardiographic Characterization of Embryonic Zebrafish", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Zebrafish, heart, electrophysiology, ECG", "note": "\u00a9 2004 IEEE. Issue Date: 1-5 Sept. 2004. Date of Current Version: 14 March 2005.", "abstract": "The zebrafish (Danio rerio) has emerged as one of the primary experimental models of developmental cardiovascular research. Recent progress in flow visualization techniques along with the existing genetic map of the species has made zebrafish amenable to a variety of experiments relating cardiac developmental structure and function. One essential tool in establishing the proper functioning of the heart is the electrocardiogram (ECG). This study presents a methodology whereby the ECGs of embryonic zebrafish could be used in assessing the electrophysiological consequences of genetically-, mechanically-, or pharmacokinetically-induced cardiac perturbations. Five day post-fertilization (dpf) embryos produced repeating bimodal ECGs with clearly distinguished atrial (P) and ventricular (R) depolarization waves. P-R intervals along with P-P intervals are cited.", "date": "2004-09", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "3615-3617", "id_number": "CaltechAUTHORS:20110823-085037968", "isbn": "0-7803-8439-3", "book_title": "EMBC 2004 : 26th Annual International Conference of the IEEE Engineering in Medicine and Biology Society", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110823-085037968", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/IEMBS.2004.1404016", "pub_year": "2004", "author_list": "Forouhar, A. S.; Hove, J. R.; et el." }, { "id": "https://authors.library.caltech.edu/records/64d44-9gx48", "eprint_id": 87669, "eprint_status": "archive", "datestamp": "2023-08-19 13:57:43", "lastmod": "2024-01-14 20:21:10", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Arias-I", "name": { "family": "Arias", "given": "I." } }, { "id": "Serebrinsky-S", "name": { "family": "Serebrinsky", "given": "S." } }, { "id": "Ortiz-M", "name": { "family": "Ortiz", "given": "M." }, "orcid": "0000-0001-5877-4824" } ] }, "title": "A cohesive model of fatigue of ferroelectric materials under electro-mechanical cyclic loading", "ispublished": "unpub", "full_text_status": "public", "keywords": "Fatigue, nucleation, ferroelectrics, electric loading, mechanical loading", "note": "\u00a9 2004 Society of Photo-Optical Instrumentation Engineers (SPIE). \n\nWe are grateful for support provided by the Army Research Office through Caltech's MURI on Engineering Microstructural Complexity in Ferroelectric Devices.\n\nPublished - 371.pdf
", "abstract": "A cohesive fatigue-crack nucleation and growth model for ferroelectric materials under electro-mechanical loading is presented. The central feature of the model is a hysteretic cohesive law which couples the mechanical and electrical fields. This law can be used in conjunction with general constitutive relations of bulk behavior, possibly including domain switching, in order to predict fatigue crack growth under arbitrary loading conditions. Another appealing feature of the model is its ability to predict fatigue-crack nucleation. Despite the scarcity and uncertainty of the experimental data, comparisons with PZT fatigue-life data are encouraging.", "date": "2004-07-21", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "371-378", "id_number": "CaltechAUTHORS:20180709-154444981", "isbn": "0819453048", "book_title": "Smart Structures and Materials 2004: Active Materials: Behavior and Mechanics", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180709-154444981", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Army Research Office (ARO)" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Lagoudas-D-C", "name": { "family": "Lagoudas", "given": "Dimitris C." } } ] }, "doi": "10.1117/12.540097", "primary_object": { "basename": "371.pdf", "url": "https://authors.library.caltech.edu/records/64d44-9gx48/files/371.pdf" }, "pub_year": "2004", "author_list": "Arias, I.; Serebrinsky, S.; et el." }, { "id": "https://authors.library.caltech.edu/records/xw7qb-cdp97", "eprint_id": 88248, "eprint_status": "archive", "datestamp": "2023-08-19 13:57:33", "lastmod": "2024-01-14 20:30:44", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Arias-I", "name": { "family": "Arias", "given": "Irene" } }, { "id": "Achenbach-J-D", "name": { "family": "Achenbach", "given": "Jan D." } } ] }, "title": "A model for the ultrasonic detection of surface-breaking cracks by the scanning laser-source technique", "ispublished": "unpub", "full_text_status": "public", "keywords": "Laser ultrasonics, thermoelastic regime, line-source, surface-breaking crack, modelling, Scanning Laser Source technique", "note": "\u00a9 2004 Society of Photo-optical Instrumentation Engineers (SPIE). \n\nThis work was carried out in the course of research funded by the Federal Aviation Administration under Contract #DFTA 03-98-D-0008 through the Air Transportation Center of Excellence in Airworthiness Assurance.\n\nPublished - 123.pdf
", "abstract": "A model for the Scanning Laser Source (SLS) technique is presented. The SLS is a novel laser based inspection method for the ultrasonic detection of small surface-breaking cracks. The generated ultrasonic signal is monitored as a line-focused laser is scanned over the defect. Characteristic changes in the amplitude and the frequency content are observed. The modelling approach is based on the decomposition of the field generated by the laser in a cracked two-dimensional half-space, by virtue of linear superposition, into the incident and the scattered fields. The incident field is that generated by laser illumination of a defect-free half-space. A thermoelastic model has been used which takes account of the effect of thermal diffusion, as well as the finite width and duration of the laser source. The scattered field incorporates the interactions of the incident field with the surface-breaking crack. It has been analyzed numerically by a direct frequency domain boundary element method. A comparison with an experiment for a large defect shows that the model captures the observed phenomena.", "date": "2004-07-20", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "123-131", "id_number": "CaltechAUTHORS:20180725-105501299", "isbn": "9780819453105", "book_title": "Nondestructive Evaluation and Health Monitoring of Aerospace Materials and Composites III", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180725-105501299", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Federal Aviation Administration (FAA)", "grant_number": "DFTA 03-98-D-0008" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Shull-P-J", "name": { "family": "Shull", "given": "Peter J." } }, { "id": "Gyekenyesi-A-L", "name": { "family": "Gyekenyesi", "given": "Andrew L." } } ] }, "doi": "10.1117/12.540109", "primary_object": { "basename": "123.pdf", "url": "https://authors.library.caltech.edu/records/xw7qb-cdp97/files/123.pdf" }, "pub_year": "2004", "author_list": "Arias, Irene and Achenbach, Jan D." }, { "id": "https://authors.library.caltech.edu/records/a7m1g-59e52", "eprint_id": 3303, "eprint_status": "archive", "datestamp": "2023-08-22 01:43:38", "lastmod": "2024-01-11 23:25:18", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Parkin-K-L-G", "name": { "family": "Parkin", "given": "Kevin L. G." } }, { "id": "Culick-F-E-C", "name": { "family": "Culick", "given": "Fred E. C." } } ] }, "title": "Feasibility and Performance of the Microwave Thermal Rocket Launcher", "ispublished": "unpub", "full_text_status": "public", "keywords": "space vehicles; propulsion; masers; plasma production; atmospheric electromagnetic wave propagation; force measurement; hydrogen", "note": "\u00a92004 American Institute of Physics \n\nThe author is grateful to Prof. Albert Ratner for numerous helpful discussions and to the Caltech President's Fund for supporting this work under grant PF-495 / NASA contract NAS7-1407.", "abstract": "Beamed-energy launch concepts employing a microwave thermal thruster are feasible in principle, and microwave sources of sufficient power to launch tons into LEO already exist. Microwave thermal thrusters operate on an analogous principle to nuclear thermal thrusters, which have experimentally demonstrated specific impulses exceeding 850 seconds. Assuming such performance, simple application of the rocket equation suggests that payload fractions of 10% are possible for a single stage to orbit (SSTO) microwave thermal rocket. We present an SSTO concept employing a scaled X-33 aeroshell. The flat aeroshell underside is covered by a thin-layer microwave absorbent heat-exchanger that forms part of the thruster. During ascent, the heat-exchanger faces the microwave beam. A simple ascent trajectory analysis incorporating X-33 aerodynamic data predicts a 10% payload fraction for a 1 ton craft of this type. In contrast, the Saturn V had 3 non-reusable stages and achieved a payload fraction of 4%.", "date": "2004-03-30", "date_type": "published", "publisher": "American Institute of Physics", "place_of_pub": "Melville, NY", "pagerange": "407-417", "id_number": "CaltechAUTHORS:PARaipcp04a", "isbn": "0-7354-0175-6", "book_title": "Beamed energy propulsion : Second International Symposium on Beamed Energy Propulsion : Sendai, Japan, 20-23 October 2003", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:PARaipcp04a", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "name": { "family": "Komurasaki", "given": "Kimiya" } } ] }, "doi": "10.1063/1.1721019", "primary_object": { "basename": "PARaipcp04a.pdf", "url": "https://authors.library.caltech.edu/records/a7m1g-59e52/files/PARaipcp04a.pdf" }, "pub_year": "2004", "author_list": "Parkin, Kevin L. G. and Culick, Fred E. C." }, { "id": "https://authors.library.caltech.edu/records/5v1by-jbd51", "eprint_id": 3304, "eprint_status": "archive", "datestamp": "2023-08-22 01:43:43", "lastmod": "2024-01-11 23:25:20", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Parkin-K-L-G", "name": { "family": "Parkin", "given": "Kevin L. G." } }, { "id": "DiDomenico-L-D", "name": { "family": "DiDomenico", "given": "Leo D." } }, { "id": "Culick-F-E-C", "name": { "family": "Culick", "given": "Fred E. C." } } ] }, "title": "The Microwave Thermal Thruster Concept", "ispublished": "unpub", "full_text_status": "public", "keywords": "space vehicles; propulsion; microwave devices; masers; atmospheric electromagnetic wave propagation; plasma production; power measurement; force measurement", "note": "\u00a92004 American Institute of Physics \n\nWe would like to thank Prof. William Bridges, Prof. David Rutledge, Prof. Hans Hornung, Mr. Tobias Kippenburg, Mr. Sean Spillane, Dr. Mark Barton, and Dr. Jordin Kare for helpful conversations. We would also like to thank the Caltech President's Fund for funding this work under grant PF-495 / NASA contract NAS7-1407.", "abstract": "The microwave thermal thruster heats propellant via a heat-exchanger then expands it through a rocket nozzle to produce thrust. The heat-exchanger is simply a microwave-absorbent structure through which propellant flows in small channels. Nuclear thermal thrusters are based on an analogous principle, using neutrons rather than microwaves, and have experimentally demonstrated specific impulses exceeding 850 seconds. A microwave equivalent will likely have a similar specific impulse, since both nuclear and microwave thermal thrusters are ultimately constrained by material thermal limits, rather than the energy-density limits of chemical propellants. We present the microwave thermal thruster concept by characterizing a novel variation for beamed-energy launch. In reducing the thruster concept to practice, the enabling physical process is microwave absorption by refractory materials, and we examine semiconductor and susceptor-based approaches to achieving this absorption within the heat-exchanger structure.", "date": "2004-03-30", "date_type": "published", "publisher": "American Institute of Physics", "place_of_pub": "Melville, NY", "pagerange": "418-429", "id_number": "CaltechAUTHORS:PARaipcp04b", "isbn": "0-7354-0175-6", "book_title": "Beamed energy propulsion : Second International Symposium on Beamed Energy Propulsion : Sendai, Japan, 20-23 October 2003", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:PARaipcp04b", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1063/1.1721020", "primary_object": { "basename": "PARaipcp04b.pdf", "url": "https://authors.library.caltech.edu/records/5v1by-jbd51/files/PARaipcp04b.pdf" }, "pub_year": "2004", "author_list": "Parkin, Kevin L. G.; DiDomenico, Leo D.; et el." }, { "id": "https://authors.library.caltech.edu/records/27q24-5gf17", "eprint_id": 50113, "eprint_status": "archive", "datestamp": "2023-08-19 12:52:02", "lastmod": "2023-10-17 22:31:25", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Khokhlov-A-M", "name": { "family": "Khokhlov", "given": "A. M." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "J. M." } }, { "id": "Pintgen-F", "name": { "family": "Pintgen", "given": "F." } }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "J. E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "Numerical Study of the Detonation Wave Structure in Ethylene-oxygen Mixtures", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2004 by the University of Chicago, California Institute of Technology. Published by the American Institute of Aeronautics and Astronautics, Inc. with permission.\n\nAIAA 2004-0792.\n\nPublished - 385526.pdf
", "abstract": "We examine a transition from a weakly to a highly unstable regime of a cellular\ndetonation in stoichiometric ethylene-oxygen systems with varied dilution. The\nstructure and propagation of cellular detonations is calculated using two-dimensional,\ntime-dependent, reactive Euler fluid-dynamics algorithm. A dynamically adapting mesh\nis used to resolve reaction zones, shocks, contact surfaces, and vortices in flow. A simplified\nchemical model with Arrhenius kinetics is used for all mixtures. Effects of dilution are\nmodeled by varying the adiabatic index \u03b3 and molecular weight of matter. Results are\ncompared to experimental data obtained in a detonation tube by simultaneous visualization\nof a chemical species (OH), density gradients in the reaction zone, and to soot foil\nrecords. Due to a strong sensitivity of the post-shock temperature to variations of \u03b3,\nthe degree of chemical - fluid dynamics coupling inside the detonation structure varies\nsignificantly with dilution. Variations of the equation of state with dilution can account\nfor and could be the main mechanism explaining a wide range of detonation behavior\nobserved in the experiments.", "date": "2004-01", "date_type": "published", "publisher": "AIAA", "place_of_pub": "Reston, VA", "id_number": "CaltechAUTHORS:20140930-083310072", "isbn": "978-1-62410-078-9", "book_title": "42nd AIAA Aerospace Sciences Meeting and Exhibit", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140930-083310072", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2004-792", "primary_object": { "basename": "385526.pdf", "url": "https://authors.library.caltech.edu/records/27q24-5gf17/files/385526.pdf" }, "pub_year": "2004", "author_list": "Khokhlov, A. M.; Austin, J. M.; et el." }, { "id": "https://authors.library.caltech.edu/records/4420n-bbv98", "eprint_id": 51654, "eprint_status": "archive", "datestamp": "2023-08-19 12:46:42", "lastmod": "2023-10-18 16:59:33", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Jackson-S-I", "name": { "family": "Jackson", "given": "S. I." } }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "J. E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "Detonation Initiation via Imploding Shock Waves", "ispublished": "unpub", "full_text_status": "public", "note": "Copyright \u00a9 2004 by California Institute of Technology. Published by the American Institute of Aeronautics and Astronautics,\nInc. with permission\n\nThe authors would like to thank P. Buraczewski for his design work as well as J. Haggerty, B. St. John,\nand A. Kiani for their patience and expertise during the construction process. We are also grateful to Dr. G.\nRoy at the Office of Naval Research and Dr. J. Blevins and Dr. C. Morris at NASA MSFC for their support\nand would like to acknowledge discussions on shock implosion with Dr. C. Li and Dr. K. Kailasanath.\nThis work was supported by the Office of Naval Research Grant Detonation Initiation by Annular Jets\nand Shock Waves (ONR grant number N00014-03-1-0931) and the National Aeronautics and Space Administration through the Graduate Student Researchers Program (Grant number NGT8-52937).\n\nPublished - detonation_initiation.pdf
", "abstract": "An imploding annular shock wave driven by a jet of air was used to initiate detonations\ninside a 76 mm diameter tube. The tube was filled with a test gas composed of either\nstoichiometric ethylene-oxygen or propane-oxygen diluted with nitrogen. The strength of\nthe imploding shock wave and the sensitivity of the test gas were varied in an effort to\nfind the minimum shock strength required for detonation of each test mixture. The results\nshow that the minimum required shock strength increases with mixture sensitivity and\nsuggest that impractically large shock driver pressures are required to initiate detonations\nin ethylene-air or propane-air mixtures when using this technique.", "date": "2004", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautic", "id_number": "CaltechAUTHORS:20141112-111650713", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141112-111650713", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-03-01-0931" }, { "agency": "NASA Graduate Student Research Fellowship", "grant_number": "NGT8-52937" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2004-3919", "primary_object": { "basename": "detonation_initiation.pdf", "url": "https://authors.library.caltech.edu/records/4420n-bbv98/files/detonation_initiation.pdf" }, "pub_year": "2004", "author_list": "Jackson, S. I. and Shepherd, J. E." }, { "id": "https://authors.library.caltech.edu/records/qp1gf-49896", "eprint_id": 41509, "eprint_status": "archive", "datestamp": "2023-08-19 12:46:02", "lastmod": "2024-01-13 06:04:19", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bobba-K", "name": { "family": "Bobba", "given": "Kumar" } }, { "id": "Doyle-J-C", "name": { "family": "Doyle", "given": "John" }, "orcid": "0000-0002-1828-2486" }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "Mory" } } ] }, "title": "A Reynolds number independent model for turbulence in Couette flow", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Turbulence, vortices, input-output measures", "note": "\u00a9 2004 Kluwer Academic.", "abstract": "In this paper we study theoretically and computationally the dynamics\nof linearized stream-wise constant Navier-Stokes equations, under\nexternal time varying deterministic disturbances.", "date": "2004", "date_type": "published", "publisher": "Kluwer Academic", "place_of_pub": "Boston, MA", "pagerange": "145-149", "id_number": "CaltechAUTHORS:20130924-130804582", "isbn": "9781402017759", "book_title": "IUTAM Symposium on Reynolds Number Scaling in Turbulent Flow", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130924-130804582", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Smits-A-J", "name": { "family": "Smits", "given": "Alexander J." } } ] }, "pub_year": "2004", "author_list": "Bobba, Kumar; Doyle, John; et el." }, { "id": "https://authors.library.caltech.edu/records/x7weq-emn82", "eprint_id": 72443, "eprint_status": "archive", "datestamp": "2023-08-19 11:49:21", "lastmod": "2023-10-23 22:34:52", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "LoBosco-D-M", "name": { "family": "LoBosco", "given": "David M." } }, { "id": "Miller-D-W", "name": { "family": "Miller", "given": "David W." }, "orcid": "0000-0001-6099-0614" }, { "id": "Blaurock-C", "name": { "family": "Blaurock", "given": "Carl" } } ] }, "title": "Multidisciplinary Control of a Sparse Interferometric Array Satellite Testbed", "ispublished": "unpub", "full_text_status": "public", "keywords": "sparse aperture, multiple-aperture optical systems, fizeau interferometer, phased telescope array, attitude control systems, control of optomechanical systems", "note": "\u00a9 2003 American Institute of Aeronautics and Astronautics. \n\nThis research was supported by the NRO Director's Innovation Initiative (DII) and Mide Technology Corporation. Authors would like to thank Alice K. Liu at NASA Goddard Space Flight Center for her initial contribution to the ARGOS attitude control system.\n\nPublished - ARGOS_AIAAGNC.pdf
", "abstract": "The MIT Adaptive Reconnaissance Golay-3 Optical Satellite (ARGOS) is a wide-angle Fizeau interferometer spacecraft testbed. Designing a space-based interferometer, which requires such high tolerances on pointing and alignment for its apertures, presents unique multidisciplinary challenges in the areas of structural dynamics, controls and multi-aperture phasing active optics. In meeting these challenges, emphasis is placed on modularity in spacecraft subsystems and optics as a means of allowing expandability and upgradeability. For the interferometer to function properly, unique methods of coherent wave front sensing are developed and used for error detection in control of the Fast Steering Mirrors (FSMs). The space environment is simulated by floating ARGOS on a frictionless air-bearing that allows it to track fast moving satellites such as the International Space Station (ISS), planets or point stars. A System Identification is performed on ARGOS to determine its dynamic properties and to design optimal controllers for\nthe Attitude Control System (ACS). ACS sensors include an electronic compass with a 2-axis tip-tilt sensor, a viewfinder camera with centroiding algorithm, and a 3-axis rate gyroscope. Nonlinear, quaternion-based control is employed using reaction wheels as the spacecraft's actuators.", "date": "2003-08", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics (AIAA)", "id_number": "CaltechAUTHORS:20161130-104041149", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161130-104041149", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "National Reconnaissance Office" }, { "agency": "Mide Technology Corporation" }, { "agency": "NASA" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.2003-5433", "primary_object": { "basename": "ARGOS_AIAAGNC.pdf", "url": "https://authors.library.caltech.edu/records/x7weq-emn82/files/ARGOS_AIAAGNC.pdf" }, "pub_year": "2003", "author_list": "Chung, Soon-Jo; LoBosco, David M.; et el." }, { "id": "https://authors.library.caltech.edu/records/5behc-07189", "eprint_id": 4963, "eprint_status": "archive", "datestamp": "2023-08-22 00:45:05", "lastmod": "2023-10-16 18:01:35", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Valentino-J-P", "name": { "family": "Valentino", "given": "Joseph P." } }, { "id": "Darhuber-A-A", "name": { "family": "Darhuber", "given": "Anton A." } }, { "id": "Troian-S-M", "name": { "family": "Troian", "given": "Sandra M." }, "orcid": "0000-0003-1224-6377" }, { "id": "Wagner-S", "name": { "family": "Wagner", "given": "Sigurd" } } ] }, "title": "Thermocapillary actuation of liquids using patterned microheater arrays", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 Copyright 2003 IEEE. Reprinted with permission. \n\nThis work is funded by NSF grant CTS-0088774, MRSEC grant DMR-9809483, and a NJCST grant.", "abstract": "We demonstrate a microfluidic actuation technique capable of directing nanoliter liquid samples on the surface of a glass substrate through the use of both electronically addressable heater arrays and chemical patterning. Pathways for liquid movement are delineated by the arrangement of microheaters, which also provide the thermocapillary actuating force. The drops are confined by selectively depositing a fluorinated monolayer to the surface, which defines the channel edges. Operating voltages in the range of 2-3V were used to move, split, and trap liquids. This fluid transportation technique enables direct access to liquid samples for handling and diagnostic purposes and offers a low power alternative to existing microfluidic systems.", "date": "2003-07-28", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Los Alamitos, CA", "pagerange": "667-669", "id_number": "CaltechAUTHORS:VALtransducers03", "isbn": "0-7803-7731-1", "book_title": "Proceedings of the 12th International Conference on TRANSDUCERS, Solid-State Sensors, Actuators and Microsystems, Boston, June 8-12, 2003", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:VALtransducers03", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "primary_object": { "basename": "VALtransducers03.pdf", "url": "https://authors.library.caltech.edu/records/5behc-07189/files/VALtransducers03.pdf" }, "pub_year": "2003", "author_list": "Valentino, Joseph P.; Darhuber, Anton A.; et el." }, { "id": "https://authors.library.caltech.edu/records/yek7m-rrj53", "eprint_id": 50343, "eprint_status": "archive", "datestamp": "2023-08-19 10:33:21", "lastmod": "2023-10-17 22:57:03", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Pintgen-F", "name": { "family": "Pintgen", "given": "F." } }, { "id": "Austin-J-M", "name": { "family": "Austin", "given": "J. M." } }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "J. E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "Detonation Front Structure: Variety and Characterization", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2003 Torus-Press.\n\nThis work was supported by the Office of Naval Research, Multidisciplinary University\nResearch Initiative Multidisciplinary Study of Pulse Detonation Engine,\ngrant 00014-99-1-0744, subcontract 1686-ONR-0744.", "abstract": "The structure of multifront or cellular detonation waves has been studied\nusing Schlieren, planar laser-induced fluorescence (PLIF) imaging of the\nOH radical, and soot foils in three mixtures with varying regularity.\nThese are: stoichiometric H_2-O_2 diluted with Ar, stoichiometric H_2-O_2 diluted with N_2, and stoichiometric H_2-N_2O diluted with N_2, all at\n20 kPa initial pressure. Very different structures are observed in each\nmixture. These differences are most striking on the PLIF images, which\nare used as a starting point for a qualitative discussion and interpretation\nof the features seen on the Schlieren images and soot foils. It is clear\nthat the detonation propagation mechanism in mixtures with irregular\ncellular structure may be much more complex than in mixtures with\nregular cellular structure.", "date": "2003", "date_type": "published", "publisher": "Torus-Press", "place_of_pub": "Moscow", "pagerange": "105-116", "id_number": "CaltechAUTHORS:20141010-143811840", "isbn": "9785945880122", "book_title": "Confined detonations and pulse detonation engines", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141010-143811840", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "00014-99-1-0744, subcontract 1686-ONR-0744" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Roy-G-D", "name": { "family": "Roy", "given": "Gabriel D." } } ] }, "pub_year": "2003", "author_list": "Pintgen, F.; Austin, J. M.; et el." }, { "id": "https://authors.library.caltech.edu/records/dksq3-t4x69", "eprint_id": 98245, "eprint_status": "archive", "datestamp": "2023-08-22 00:02:27", "lastmod": "2024-01-14 21:54:53", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Aubry-S", "name": { "family": "Aubry", "given": "S." } }, { "id": "Ortiz-M", "name": { "family": "Ortiz", "given": "M." }, "orcid": "0000-0001-5877-4824" } ] }, "title": "Variational Methods in Non-Convex Plasticity", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Crystals; microstructure; laminates; lamellar boundaries; misorientation angle; lamellar-boundary spacings; plasticity; large deformations; latent hardening; relaxation", "note": "\u00a9 Springer Science+Business Media Dordrecht 2003. \n\nWe are grateful for support provided by the US Department of Energy through Caltech's ASCI/ASAP Center for the Simulation of the Dynamic Behavior of Solids. We are also indebted to Darcy Hughes for many useful discussions and suggestions, and for making her data available to us.", "abstract": "We show how the theory of crystals with microstructure developed by Ortiz et al. can be applied to predict salient aspects of the body of experimental data compiled by Hughes et al. regarding lamellar dislocation structures in crystals deformed to large strains. The theory correctly predicts the statistics of misorientation angles and lamellar boundary spacings; and the scaling of the average misorientation and spacing with increasing macroscopic strain.", "date": "2003", "date_type": "published", "publisher": "Springer", "place_of_pub": "Dordrecht", "pagerange": "55-66", "id_number": "CaltechAUTHORS:20190826-124740658", "isbn": "9789048162390", "book_title": "IUTAM Symposium on Computational Mechanics of Solid Materials at Large Strains", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190826-124740658", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Department of Energy (DOE)" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Miehe-C", "name": { "family": "Miehe", "given": "Christian" } } ] }, "doi": "10.1007/978-94-017-0297-3_5", "pub_year": "2003", "author_list": "Aubry, S. and Ortiz, M." }, { "id": "https://authors.library.caltech.edu/records/vpc73-16z28", "eprint_id": 72192, "eprint_status": "archive", "datestamp": "2023-08-19 10:24:04", "lastmod": "2024-01-13 20:20:36", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Miller-D-W", "name": { "family": "Miller", "given": "David W." }, "orcid": "0000-0001-6099-0614" }, { "id": "de-Weck-O-L", "name": { "family": "de-Weck", "given": "Olivier L." } } ] }, "title": "Design and implementation of sparse aperture imaging systems", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2002 International Society for Optical Engineering. \n\nThis research was supported by the NRO Director's Innovation Initiative (DII) under contracts number, NRO-000-01-C-0207.\n\nPublished - 181_1.pdf
", "abstract": "In order to better understand the technological difficulties involved in designing and building a sparse aperture array, the challenge of building a white light Golay-3 telescope was undertaken. The MIT Adaptive Reconnaissance Golay-3 Optical Satellite (ARGOS) project exploits wide-angle Fizeau interferometer technology with an emphasis on modularity in the optics and spacecraft subsystems. Unique design procedures encompassing the nature of coherent wavefront sensing, control and combining as well as various system engineering aspects to achieve cost effectiveness, are developed. To demonstrate a complete spacecraft in a 1-g environment, the ARGOS system is mounted on a frictionless air-bearing, and has the ability to track fast orbiting satellites like the ISS or the planets. Wavefront sensing techniques are explored to mitigate initial misalignment and to feed back real-time aberrations into the optical control loop. This paper presents the results and the lessons learned from the conceive, design and implementation phases of ARGOS. A preliminary assess-ment shows that the beam combining problem is the most challenging aspect of sparse optical arrays. The need for optical control is paramount due to tight beam combining tolerances. The wavefront sensing/control requirements appear to be a major technology and cost driver.", "date": "2002-12-01", "date_type": "published", "publisher": "Society of Photo-Optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "181-192", "id_number": "CaltechAUTHORS:20161121-093035571", "isbn": "0-8194-4628-9", "book_title": "Highly Innovative Space Telescope Concepts", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161121-093035571", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "National Reconnaissance Office", "grant_number": "NRO-000-01-C-0207" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "MacEwen-H-A", "name": { "family": "MacEwen", "given": "Howard A." } } ] }, "doi": "10.1117/12.460077", "primary_object": { "basename": "181_1.pdf", "url": "https://authors.library.caltech.edu/records/vpc73-16z28/files/181_1.pdf" }, "pub_year": "2002", "author_list": "Chung, Soon-Jo; Miller, David W.; et el." }, { "id": "https://authors.library.caltech.edu/records/fz6km-s5b40", "eprint_id": 27586, "eprint_status": "archive", "datestamp": "2023-08-19 10:05:24", "lastmod": "2024-01-13 05:45:48", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Dabiri-J-O", "name": { "family": "Dabiri", "given": "J. O." }, "orcid": "0000-0002-6722-9008" }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "M." }, "orcid": "0000-0003-0754-4193" } ] }, "title": "Toward empirical evaluation of left ventricle function: A novel mathematical mapping", "ispublished": "unpub", "full_text_status": "public", "keywords": "ventricle, myocardium, mechanics, modeling", "note": "\u00a9 2002 IEEE. \n\nDate of Current Version: 06 January 2003.\n\nPublished - DABiembs02.pdf
", "abstract": "A strategy is developed to facilitate quantitative\nanalysis of left ventricle morphology based on clinically\nmeasured surface geometry and muscle fiber patterns rather\nthan lower order geometric approximations previously\nrequired. A transfer function is derived which maps measured\nthree-dimensional ventricle surfaces and associated muscle\nfiber patterns to a right circular cylinder, while preserving characteristic kinematics of the system. Functional analysis of ventricular morphology at various stages of the cardiac cycle proceeds by using classical methods on the cylindrical ventricle model, with substantially reduced analytical complexity when compared to similar calculations on the real ventricle shape.\nFunctional morphology of the real ventricle shape at any stage of the cardiac cycle is subsequently deduced by applying the inverse of the transfer function in order to map the computed right circular cylinder back to its corresponding real ventricle shape. Limitations of the method are discussed in the context of real left ventricle performance, and extension of the method for analysis of functional morphology in other biomechanical systems is explored.", "date": "2002-10", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "1270-1271", "id_number": "CaltechAUTHORS:20111102-112552555", "isbn": "0-7803-7612-9", "book_title": "Second Joint EMBS-BMES Conference 2002", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20111102-112552555", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/IEMBS.2002.1106382", "primary_object": { "basename": "DABiembs02.pdf", "url": "https://authors.library.caltech.edu/records/fz6km-s5b40/files/DABiembs02.pdf" }, "pub_year": "2002", "author_list": "Dabiri, J. O. and Gharib, M." }, { "id": "https://authors.library.caltech.edu/records/swqcq-5hr02", "eprint_id": 27607, "eprint_status": "archive", "datestamp": "2023-08-19 10:05:31", "lastmod": "2024-01-13 05:45:57", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Iwaniec-A", "name": { "family": "Iwaniec", "given": "A." } }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "M." } } ] }, "title": "Bladeless blood pump - Feasibility of the design as an LVAD device", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2002 IEEE. Date of Current Version: 06 January 2003. We would like to thank IRC Grubstake program of Caltech.", "abstract": "Preliminary experimental results show that our design for a constant-flow bladeless pump has the potential to serve as a left ventricle assist device (LVAD). Tests show the ability of the design to pump above 1 liter/min, the same order of magnitude as current technology. Distinguishing features of the design include its flexibility, scalability and simplicity. Modifications to the design show significant improvements in its pumping performance, demonstrating its potential to become a commercial device.", "date": "2002-10", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, N.J.", "pagerange": "1605-1606", "id_number": "CaltechAUTHORS:20111103-110102231", "isbn": "0-7803-7612-9", "book_title": "Second Joint EMBS-BMES Conference 2002", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20111103-110102231", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "7597394", "name": "INSPEC Accession Number" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/IEMBS.2002.1106560", "pub_year": "2002", "author_list": "Iwaniec, A. and Gharib, M." }, { "id": "https://authors.library.caltech.edu/records/znfmh-07b52", "eprint_id": 27580, "eprint_status": "archive", "datestamp": "2023-08-21 23:43:30", "lastmod": "2024-01-13 05:45:42", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Gharib-M", "name": { "family": "Gharib", "given": "M." } }, { "id": "Beizai-M", "name": { "family": "Beizai", "given": "M." } }, { "id": "Saber-N-R", "name": { "family": "Saber", "given": "N. R." } } ] }, "title": "Experimental and computational studies of negative near-wall shear stress in the human aorta and its correlation with various stages of CHF", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "aorta; heart failure; retrograde; endothelium; computational fluid dynamics", "note": "\u00a9 2002 IEEE.\n\nIssue Date: 2002; Date of Current Version: 06 January 2003.", "abstract": "In this article, we report our in vitro observations demonstrating that reduced blood flow combined with increased heartbeat can lead to a retrograde flow adjacent to the vessel wall and thereby high negative wall shear stress over a major part of cardiac cycle. We attempt to map the correlation between the level of retrograde flow in the descending aorta and the severity of congestive heart failure (CHF), using both experimental methods and computational fluid dynamics (CFD) simulations.", "date": "2002-10", "date_type": "published", "publisher": "IEEE", "pagerange": "1254-1255", "id_number": "CaltechAUTHORS:20111102-095344509", "isbn": "0-7803-7612-9", "book_title": "Second Joint EMBS-BMES Conference 2002", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20111102-095344509", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "7591607", "name": "INSPEC Accession Number" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/IEMBS.2002.1106374", "pub_year": "2002", "author_list": "Gharib, M.; Beizai, M.; et el." }, { "id": "https://authors.library.caltech.edu/records/vek30-48b57", "eprint_id": 13118, "eprint_status": "archive", "datestamp": "2023-08-19 10:05:10", "lastmod": "2023-10-17 21:47:14", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Acevedo-Bolton-G", "name": { "family": "Acevedo-Bolton", "given": "G." } }, { "id": "Hove-J-R", "name": { "family": "Hove", "given": "J. R." } }, { "id": "Koester-R", "name": { "family": "Koester", "given": "R." } }, { "id": "Forouhar-A", "name": { "family": "Forouhar", "given": "A." } }, { "id": "Fraser-S-E", "name": { "family": "Fraser", "given": "S. E." }, "orcid": "0000-0002-5377-0223" }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "M." }, "orcid": "0000-0003-0754-4193" } ] }, "title": "In-Vivo Applications of Microscale Digital Particle Image Velocimetry", "ispublished": "unpub", "full_text_status": "public", "keywords": "DPIV, hemodynamics, cardiogenesis, microscopy", "note": "\u00a9 2002 IEEE. Reprinted with permission. \n\nPublication Date: 23-26 Oct. 2002.\n\nPublished - ACEiembs02.pdf
", "abstract": "Digital particle image velocimetry (DPIV) is an extremely powerful technique for quantitative flow measurements. In order to perform hemodynamic measurements in embryonic hearts, DPIV analysis was performed on both Zebrafish (Danio rerio) and Quail (Coturnix coturnix japonica) embryos. A protocol for performing DPIV at the microscale with microscopy and high-speed imaging is presented. Results show the presence of vortices and jets at low Reynolds numbers implying a high shear on vessel walls, and suggest that hemodynamics may play an important role in future heart development studies.", "date": "2002-10", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "1303-1304", "id_number": "CaltechAUTHORS:ACEiembs02", "isbn": "0780376129", "book_title": "Second Joint EMBS/BMES Conference, Houston TX, 23-25 October 2002", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:ACEiembs02", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/IEMBS.2002.1106399", "primary_object": { "basename": "ACEiembs02.pdf", "url": "https://authors.library.caltech.edu/records/vek30-48b57/files/ACEiembs02.pdf" }, "pub_year": "2002", "author_list": "Acevedo-Bolton, G.; Hove, J. R.; et el." }, { "id": "https://authors.library.caltech.edu/records/539m4-1hz26", "eprint_id": 41247, "eprint_status": "archive", "datestamp": "2023-08-21 23:43:52", "lastmod": "2024-01-13 06:03:55", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Gharib-M", "name": { "family": "Gharib", "given": "Mory" } }, { "id": "Pereira-F", "name": { "family": "Pereira", "given": "Francisco" } }, { "id": "Dabiri-D", "name": { "family": "Dabiri", "given": "Dana" } }, { "id": "Modarress-D", "name": { "family": "Modarress", "given": "Darius" } } ] }, "title": "Quantitative Flow Visualization - Toward a Comprehensive Flow Diagnostic Tool", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "imaging; visualization; PIV; DPIV; diagnostics", "note": "\u00a9 2002 New York Academy of Sciences.\n\nArticle first published online: 24 Jan. 2006.\n\nThis research was supported by the Office of Naval Research (Contract\nN000140010110). Defocusing digital particle image velocimetry (DDPIV) technology\nis protected under a U.S. patent through the California Institute of Technology.", "abstract": "Quantitative flow visualization has many roots and has taken several\napproaches. The advent of digital image processing has made it practical\nto extract useful information from every kind of flow image. In a direct\napproach, the image intensity or color (wavelength or frequency) can be used\nas an indication of concentration, density and temperature field, or gradients\nof these scalar fields in the flow.\nFor whole-field velocity measurement, the\nmethod of choice for experimental fluid mechanicians has been digital particle\nimage velocimetry (DPIV). This paper presents a novel approach to extend the\nDPIV technique from a planar method to a full three-dimensional volume\nmapping technique.", "date": "2002-10", "date_type": "published", "publisher": "New York Academy of Sciences", "place_of_pub": "New York, NY", "pagerange": "1-9", "id_number": "CaltechAUTHORS:20130911-110931833", "isbn": "1-57331-370-X", "book_title": "Visualization and imaging in transport phenomena", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130911-110931833", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "N000140010110" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1111/j.1749-6632.2002.tb04546.x", "pub_year": "2002", "author_list": "Gharib, Mory; Pereira, Francisco; et el." }, { "id": "https://authors.library.caltech.edu/records/sjrvh-hxe54", "eprint_id": 72981, "eprint_status": "archive", "datestamp": "2023-08-19 09:52:08", "lastmod": "2023-10-24 14:53:05", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chung-Soon-Jo", "name": { "family": "Chung", "given": "Soon-Jo" }, "orcid": "0000-0002-6657-3907" }, { "id": "Miller-D-W", "name": { "family": "Miller", "given": "David W." }, "orcid": "0000-0001-6099-0614" } ] }, "title": "Design, Implementation and Operation of a Sparse Aperture Imaging Satellite Testbed", "ispublished": "unpub", "full_text_status": "public", "keywords": "sparse aperture, multiple-aperture optical systems, telescopes, fizeau interferometer, phased telescope array", "note": "\u00a9 2002.\n\nPublished - Design_Implementation_and_Operation_of_a_Sparse_Aperture_Imaging.pdf
", "abstract": "In order to better understand the technological difficulties involved in designing and building a sparse aperture array, the challenge of building a white light Golay-3 telescope was undertaken. The MIT Adaptive Reconnaissance Golay-3 Optical Satellite (ARGOS) project exploits wide-angle Fizeau interferometer technology with an emphasis on modularity in the optics and spacecraft subsystems. Unique design procedures encompassing the nature of coherent wavefront sensing, control and combining as well as various system engineering aspects to achieve cost effectiveness, are developed. To demonstrate a complete spacecraft in a 1-g environment, the ARGOS system is mounted on a frictionless air-bearing, and has the ability to track fast orbiting satellites like the ISS or the planets. Wavefront sensing techniques are explored to mitigate initial misalignment and to feed back real-time aberrations into the optical control loop. This paper presents the results and the lessons learned from the conceive, design, implement and operate phases of ARGOS. A preliminary assessment shows that the beam combining problem is the most challenging aspect of sparse optical arrays. The need for optical control is paramount due to tight beam combining tolerances. The wavefront sensing/control requirements appear to be a major technology and cost driver.", "date": "2002-08", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "id_number": "CaltechAUTHORS:20161220-112255420", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161220-112255420", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "primary_object": { "basename": "Design_Implementation_and_Operation_of_a_Sparse_Aperture_Imaging.pdf", "url": "https://authors.library.caltech.edu/records/sjrvh-hxe54/files/Design_Implementation_and_Operation_of_a_Sparse_Aperture_Imaging.pdf" }, "pub_year": "2002", "author_list": "Chung, Soon-Jo and Miller, David W." }, { "id": "https://authors.library.caltech.edu/records/90mk3-4rw15", "eprint_id": 27559, "eprint_status": "archive", "datestamp": "2023-08-19 09:48:11", "lastmod": "2024-01-13 05:45:28", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Arienti-Marco", "name": { "family": "Arienti", "given": "Marco" }, "orcid": "0000-0001-8166-0016" }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "Joseph E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "Superseismic Loading and Shock Polars: An Example of Fluid-Solid Coupling", "ispublished": "unpub", "full_text_status": "public", "keywords": "shock wave effects, explosions, interface phenomena, deformation, solids, fluids", "note": "\u00a9 2002 American Institute of Physics. \n\nIssue Date: 8 July 2002. \n\nThis work was carried out at Caltech ASCI ASAP and funded by Contract B341492 under DOE Contract W-7405-ENG-48.\n\nPublished - ARIaipcp02.pdf
", "abstract": "We propose a two-dimensional problem involving fluid-solid coupling where a solution is given in closed form. The upper half of the domain is modeled as an isotropic solid;\nthe lower part as a compressible gas. The loading of the solid at the fluid-solid boundary is called superseismic when its speed is larger than the speed of propagation of disturbances in the bulk of the material. The loading is modeled by a shock coupled to the deformation of the\nboundary. The problem is relevant to high explosive applications, since it is very similar to the interaction between an explosive and the casing in a cylinder test experiment. Within this framework, we show the existence of self-similar solutions in the reference frame moving\nwith the shock wave.", "date": "2002-07-08", "date_type": "published", "publisher": "American Institute of Physics", "place_of_pub": "Melville, N.Y.", "pagerange": "251-254", "id_number": "CaltechAUTHORS:20111101-135243222", "isbn": "0-7354-0068-7", "book_title": "Shock Compression of Condensed Matter-2001", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20111101-135243222", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Department of Energy (DOE)", "grant_number": "B341492" }, { "agency": "Department of Energy (DOE)", "grant_number": "W-7405-ENG-48" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Furnish-M-D", "name": { "family": "Furnish", "given": "M. D." } }, { "id": "Thadhani-N-N", "name": { "family": "Thadhani", "given": "N. N." } }, { "id": "Horie-Y", "name": { "family": "Horie", "given": "Y." } } ] }, "doi": "10.1063/1.1483527", "primary_object": { "basename": "ARIaipcp02.pdf", "url": "https://authors.library.caltech.edu/records/90mk3-4rw15/files/ARIaipcp02.pdf" }, "pub_year": "2002", "author_list": "Arienti, Marco and Shepherd, Joseph E." }, { "id": "https://authors.library.caltech.edu/records/1wnen-kb247", "eprint_id": 3393, "eprint_status": "archive", "datestamp": "2023-08-21 23:32:05", "lastmod": "2024-01-11 23:25:22", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Meyers-M-A", "name": { "family": "Meyers", "given": "M. A." } }, { "id": "Gregori-F", "name": { "family": "Gregori", "given": "F." } }, { "id": "Kad-B-K", "name": { "family": "Kad", "given": "B. K." } }, { "id": "Schneider-M-S", "name": { "family": "Schneider", "given": "M. S." } }, { "id": "Kalantar-D-H", "name": { "family": "Kalantar", "given": "D. H." } }, { "id": "Remington-B-A", "name": { "family": "Remington", "given": "B. A." } }, { "id": "Wark-J-S", "name": { "family": "Wark", "given": "J. S." } }, { "id": "Boehly-T", "name": { "family": "Boehly", "given": "T." } }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "G." }, "orcid": "0000-0002-2912-0001" } ] }, "title": "Plastic Deformation in Laser-Induced Shock Compression of Monocrystalline Copper", "ispublished": "unpub", "full_text_status": "public", "keywords": "high-pressure effects; shock waves; plastic deformation; copper; dislocations; twinning", "note": "\u00a92002 American Institute of Physics \n\nResearch supported by the Department of Energy Grants DEFG0398DP00212 and DEFG0300SF2202.", "abstract": "Copper monocrystals were subjected to shock compression at pressures of 10\u201360 GPa by a short (3 ns initial) duration laser pulse. Transmission electron microscopy revealed features consistent with previous observations of shock-compressed copper, albeit at pulse durations in the \u00b5s regime. The results suggest that the defect structure is generated at the shock front. A mechanism for dislocation generation is presented, providing a realistic prediction of dislocation density as a function of pressure. The threshold stress for deformation twinning in shock compression is calculated from the constitutive equations for slip, twinning, and the Swegle-Grady relationship.", "date": "2002-07-08", "date_type": "published", "publisher": "American Institute of Physics", "place_of_pub": "Melville, NY", "pagerange": "619-622", "id_number": "CaltechAUTHORS:MEYaipcp02", "isbn": "0-7354-0068-7", "book_title": "Shock compression of condensed matter--2001 : proceedings of the Conference of the American Physical Society Topical Group on Shock Compression of Condensed Matter held in Atlanta, Georgia, June 24-29, 2001", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:MEYaipcp02", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "name": { "family": "Furnish", "given": "Michael D." } }, { "name": { "family": "Horie", "given": "Yasuyuki" } }, { "name": { "family": "Thadhani", "given": "Naresh N." } } ] }, "doi": "10.1063/1.1483615", "primary_object": { "basename": "MEYaipcp02.pdf", "url": "https://authors.library.caltech.edu/records/1wnen-kb247/files/MEYaipcp02.pdf" }, "pub_year": "2002", "author_list": "Meyers, M. A.; Gregori, F.; et el." }, { "id": "https://authors.library.caltech.edu/records/jdf1z-r2j24", "eprint_id": 2823, "eprint_status": "archive", "datestamp": "2023-08-21 23:31:55", "lastmod": "2024-01-11 23:25:13", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Zhuang-S", "name": { "family": "Zhuang", "given": "Shiming" } }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "Guruswami" }, "orcid": "0000-0002-2912-0001" }, { "id": "Grady-D-E", "name": { "family": "Grady", "given": "Dennis E." } } ] }, "title": "Influence of Interface Scattering on Shock Waves in Heterogeneous Solids", "ispublished": "unpub", "full_text_status": "public", "keywords": "shock wave effects; surface scattering; inhomogeneous media; composite material interfaces; polymers", "note": "\u00a92002 American Institute of Physics \n\nThe research reported here was supported by the Solid Mechanics program at the Army Research Office (Dr. M. A. Zikry, Program Manager) and is gratefully acknowledged.\n\nPublished - ZHUaipcp02.pdf
", "abstract": "In heterogeneous media, the scattering due to interfaces between dissimilar materials play an important role in shock wave dissipation and dispersion. In this work the influence of interface scattering effect on shock waves was studied by impacting flyer plates onto periodically layered polycarbonate/6061 aluminum, polycarbonate/304 stainless steel and polycarbonate/glass composites. The experimental results (using VISAR and stress gauges) indicate that the rise time of the shock front decreases with increasing shock strength, and increases with increasing mechanical impedance mismatch between layers; the strain rate at the shock front increases by about the square of the shock stress. Experimental and numerical results also show that due to interface scattering effect the shock wave velocity in periodically layered composites decreases. In some cases the shock velocity of a layered heterogeneous composite can be lower than that of either of its components.", "date": "2002-07-08", "date_type": "published", "publisher": "American Institute of Physics", "place_of_pub": "Melville, NY", "pagerange": "709-712", "id_number": "CaltechAUTHORS:ZHUaipcp02", "isbn": "0735400687", "book_title": "Shock compression of condensed matter--2001 : proceedings of the Shock COmpression of Condensed Matter held in Atlanta, Georgia, June 24-29, 2001", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:ZHUaipcp02", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "name": { "family": "Furnish", "given": "Michael D." } }, { "name": { "family": "Thadhani", "given": "Naresh N." } }, { "name": { "family": "Horie", "given": "Yasuyuki" } } ] }, "doi": "10.1063/1.1483600", "primary_object": { "basename": "ZHUaipcp02.pdf", "url": "https://authors.library.caltech.edu/records/jdf1z-r2j24/files/ZHUaipcp02.pdf" }, "pub_year": "2002", "author_list": "Zhuang, Shiming; Ravichandran, Guruswami; et el." }, { "id": "https://authors.library.caltech.edu/records/y3p0p-q2t55", "eprint_id": 2824, "eprint_status": "archive", "datestamp": "2023-08-21 23:32:00", "lastmod": "2024-01-11 23:25:15", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "Guruswami" }, "orcid": "0000-0002-2912-0001" }, { "id": "Rosakis-A-J", "name": { "family": "Rosakis", "given": "Ares J." }, "orcid": "0000-0003-0559-0794" }, { "id": "Hodowany-J", "name": { "family": "Hodowany", "given": "Jon" } }, { "id": "Rosakis-P", "name": { "family": "Rosakis", "given": "Phoebus" } } ] }, "title": "On the Conversion of Plastic Work into Heat During High-Strain-Rate Deformation", "ispublished": "unpub", "full_text_status": "public", "keywords": "plastic deformation; aluminium alloys; titanium; temperature measurement; heat; mechanical energy storage", "note": "\u00a92002 American Institute of Physics \n\nThe research reported here was supported by the Office of Naval Research and the National Science Foundation and is gratefully acknowledged.\n\nPublished - RAVaipcp02.pdf
", "abstract": "Heat generation in metals during high-strain-rate plastic deformation was investigated. Experiments were designed to measure the partition of plastic work into heat and stored energy during dynamic deformations under adiabatic conditions. A Kolsky pressure bar was used to determine mechanical properties at high strain rates while a servo-hydraulic material testing system was used at low strain rates. For dynamic loading, in-situ temperature changes were measured using a high-speed infrared detector. The dependence of the fraction of plastic work converted to heat on strain and strain rate was determined for an aluminum 2024-T3 alloy and alpha-titanium. The flow stress and the fraction of plastic work converted to heat for 2024-T3 aluminum alloy were found to be a function of strain but not of the strain rate while they were found to be strongly dependent on strain rate for alpha-titanium.", "date": "2002-07-08", "date_type": "published", "publisher": "American Institute of Physics", "place_of_pub": "Melville, NY", "pagerange": "557-562", "id_number": "CaltechAUTHORS:RAVaipcp02", "isbn": "0735400687", "book_title": "Shock compression of condensed matter--2001 : proceedings of the Shock COmpression of Condensed Matter held in Atlanta, Georgia, June 24-29, 2001", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:RAVaipcp02", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "name": { "family": "Furnish", "given": "Michael D." } }, { "name": { "family": "Thadhani", "given": "Naresh N." } }, { "name": { "family": "Horie", "given": "Yasuyuki" } } ] }, "doi": "10.1063/1.1483600", "primary_object": { "basename": "RAVaipcp02.pdf", "url": "https://authors.library.caltech.edu/records/y3p0p-q2t55/files/RAVaipcp02.pdf" }, "pub_year": "2002", "author_list": "Ravichandran, Guruswami; Rosakis, Ares J.; et el." }, { "id": "https://authors.library.caltech.edu/records/z7exy-2k432", "eprint_id": 27709, "eprint_status": "archive", "datestamp": "2023-08-19 09:48:21", "lastmod": "2024-01-13 05:46:34", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Morano-Eric-O", "name": { "family": "Morano", "given": "Eric O." } }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "Joseph E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "Effect of reaction rate periodicity on detonation propagation", "ispublished": "unpub", "full_text_status": "public", "keywords": "detonation, reaction kinetics, shock waves, explosions", "note": "\u00a9 2002 American Institute of Physics. \n\nIssue Date: 8 July 2002. \n\nThis work was carried out at Caltech ASCI ASAP and funded by Contract B341492 under DOE Contract W-7405-ENG-48.\n\nPublished - MORaipcp02.pdf
", "abstract": "As an alternative to homogeneous reaction rates, we implement \"synthetic\" hot-spots through a depletion rate that is a function of the local pressure multiplied by a periodic function of the spatial coordinates. We investigate through numerical simulations how the detonation propagation is affected by the heterogeneous rate.", "date": "2002-07-08", "date_type": "published", "publisher": "American Institute of Physics", "place_of_pub": "Melville, N.Y.", "pagerange": "446-449", "id_number": "CaltechAUTHORS:20111109-132717938", "isbn": "0-7354-0068-7", "book_title": "Shock Compression of Condensed Matter 2001", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20111109-132717938", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Department of Energy (DOE)", "grant_number": "B341492" }, { "agency": "Department of Energy (DOE)", "grant_number": "W-7405-ENG-48" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Furnish-M-D", "name": { "family": "Furnish", "given": "M. D." } }, { "id": "Thadhani-N-N", "name": { "family": "Thadhani", "given": "N. N." } }, { "id": "Horie-Y", "name": { "family": "Horie", "given": "Y." } } ] }, "doi": "10.1063/1.1483574", "primary_object": { "basename": "MORaipcp02.pdf", "url": "https://authors.library.caltech.edu/records/z7exy-2k432/files/MORaipcp02.pdf" }, "pub_year": "2002", "author_list": "Morano, Eric O. and Shepherd, Joseph E." }, { "id": "https://authors.library.caltech.edu/records/8qprj-c2v32", "eprint_id": 99139, "eprint_status": "archive", "datestamp": "2023-08-21 22:52:27", "lastmod": "2023-10-18 17:53:40", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Vural-M", "name": { "family": "Vural", "given": "M." } }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "G." }, "orcid": "0000-0002-2912-0001" } ] }, "title": "High Strain Rate Testing of Sandwich Core Materials", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Plateau Stress; Energy Dissipation Capacity; Progressive Deformation; Quartz Single Crystal; Balsa Wood", "note": "\u00a9 2002 Kluwer Academic Publishers. \n\nThis research was supported by the Office of Naval Research (Dr. Y. D. S. Rajapakse, Scientific Officer) and is gratefully acknowledged. MV gratefully acknowledges the support provided by T\u00dcB\u0130TAK (The Scientific and Technical Research Council of Turkey) through the NATO Advanced Science Fellowship.", "abstract": "Mechanical response of a cellular sandwich core material, balsa wood, is investigated over its entire density spectrum from 55 to 380 kg/m^3. Specimens were compression loaded along the grain direction in both quasi-static and dynamic strain rates from 10^(\u22123) to 10^3 s^(\u22121). Results show that while the initial failure stress is very sensitive to the rate of loading, plateau (crushing) stress remains unaffected by the strain rate. Kinematics of deformation and micro inertial effects are suggested and discussed to explain this different behavior. Specific energy dissipation capacity of balsa wood was measured and determined to be comparable with those of fiber-reinforced polymers. As in quasi-static loading, buckling and kink band formation were identified to be two major failure modes in dynamic loading as well.", "date": "2002", "date_type": "published", "publisher": "Kluwer Academic Publishers", "place_of_pub": "Dordrecht", "pagerange": "31-42", "id_number": "CaltechAUTHORS:20191008-090739158", "isbn": "978-1-4020-0683-8", "book_title": "Recent Advances in Experimental Mechanics: In Honor of Isaac M. Daniel", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191008-090739158", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)" }, { "agency": "T\u00fcrkiye Bilimsel ve Teknolojik Ara\u015ft\u0131rma Kurumu (T\u00dcB\u0130TAK)" }, { "agency": "North Atlantic Treaty Organization (NATO)" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Gdoutos-E-E", "name": { "family": "Gdoutos", "given": "Emmanuel E." } } ] }, "doi": "10.1007/0-306-48410-2_4", "pub_year": "2002", "author_list": "Vural, M. and Ravichandran, G." }, { "id": "https://authors.library.caltech.edu/records/ej9tm-c3704", "eprint_id": 101465, "eprint_status": "archive", "datestamp": "2023-08-21 22:54:06", "lastmod": "2024-01-14 22:07:43", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Needleman-A", "name": { "family": "Needleman", "given": "A." } }, { "id": "Coker-Demirkan", "name": { "family": "Coker", "given": "D." }, "orcid": "0000-0001-7385-7089" }, { "id": "Rosakis-A-J", "name": { "family": "Rosakis", "given": "A. J." }, "orcid": "0000-0003-0559-0794" } ] }, "title": "Dynamic Crack Growth along Interfaces", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Wave Speed; Bond Line; Crack Speed; Bimaterial Interface; Shear Wave Speed", "note": "\u00a9 2002 Springer Science+Business Media Dordrecht. \n\nA.N. is grateful for the support provided by the Office of Naval Research through grant N00014-97-1-0179. D.C. and A.J.R. gratefully acknowledge the support of the Office of Naval Research through grant N00014-95-1-0453.", "abstract": "For remotely loaded cracks in isotropic elastic solids, the energy flux into the crack tip vanishes as the crack speed increases to the Rayleigh wave speed of the material, see [1]. However, theoretical and numerical studies dating back to the mid 1970's, e.g. Andrews [2], Burridge et al. [3] and Broberg [4, 5], have indicated that faster crack speeds should be possible under shear loading conditions.", "date": "2002", "date_type": "published", "publisher": "Springer", "place_of_pub": "Dordrecht", "pagerange": "261-270", "id_number": "CaltechAUTHORS:20200221-133523276", "isbn": "978-90-481-5977-2", "book_title": "IUTAM Symposium on Analytical and Computational Fracture Mechanics of Non-Homogeneous Materials", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200221-133523276", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-97-1-0179" }, { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-95-1-0453" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Karihaloo-B-L", "name": { "family": "Karihaloo", "given": "B. L." } } ] }, "doi": "10.1007/978-94-017-0081-8_29", "pub_year": "2002", "author_list": "Needleman, A.; Coker, D.; et el." }, { "id": "https://authors.library.caltech.edu/records/fde8n-wwd04", "eprint_id": 101383, "eprint_status": "archive", "datestamp": "2023-08-21 22:53:50", "lastmod": "2023-10-19 22:40:44", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Rosakis-A-J", "name": { "family": "Rosakis", "given": "A. J." }, "orcid": "0000-0003-0559-0794" }, { "id": "Yu-Chengxiang-Rena", "name": { "family": "Yu", "given": "C." }, "orcid": "0000-0003-4176-0324" }, { "id": "Ortiz-M", "name": { "family": "Ortiz", "given": "M." }, "orcid": "0000-0001-5877-4824" }, { "id": "Coker-D", "name": { "family": "Coker", "given": "D." }, "orcid": "0000-0001-7385-7089" }, { "id": "Pandolfi-A", "name": { "family": "Pandolfi", "given": "A." }, "orcid": "0000-0002-7084-7456" } ] }, "title": "Experimental and Numerical Investigation of Shear-dominated Intersonic Crack Growth and Friction in Unidirectional Composites", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Energy Release Rate; Cohesive Element; Shear Wave Speed; Rayleigh Wave Speed; Dynamic Crack Growth", "note": "\u00a9 2002 Kluwer Academic Publishers. \n\nThis investigation was supported by the Office of Naval Research (Dr. Y. D. S. Rajapakse, Scientific Officer) through grant #N00014-95-1-0453 to Caltech and is gratefully acknowledged.", "abstract": "Dynamic crack growth in unidirectional graphite/epoxy composite materials subjected to in-plane impact loading is investigated experimentally and numerically. The experiments are conducted using CGS (Coherent Gradient Sensing) Interferometry in conjunction with high-speed photography to visualize the crack growth events. Cracks are found to propagate at subsonic speeds in the Mode-I case, whereas in both mixed mode and Mode-II the crack tip speed clearly exceeds the shear wave speed of the laminate. For these intersonically growing shear (Mode-II) cracks a shock wave emanating from the crack tip is observed. This provides direct evidence that the cracks propagate faster than the shear wave speed of the composite. The crack tip speed is initally observed to jump to a level close to the axial longitudinal wave speed along the fibers (7500 m/s) and then to stabilize to a lower level of approximately 6500 m/s. This speed corresponds to the speed at which the energy release rate required for shear crack growth is non-zero as determined from asymptotic analysis. The CGS interferograms also reveal the existence of large-scale frictional contact of the crack faces behind the moving shear cracks. In addition high speed thermographic measurements are conducted that show concentrated hot spots behind the crack tip indicating crack face frictional contact. These experiments are modeled by a detailed dynamic finite element calculation involving cohesive elements, adaptive remeshing using subdivision and edge collapse, composite elements, and penalty contact. The numerical calculations are calibrated on the basis of fundamental material properties measured in the laboratory. The computational results are found to be in excellent agreement with the optical experimental measurements (crack speed record and near tip deformation field structure). For shear crack growth, the numerics also confirm the optical observation of large-scale crack face contact.", "date": "2002", "date_type": "published", "publisher": "Kluwer Academic Publishers", "place_of_pub": "Dordrecht", "pagerange": "275-288", "id_number": "CaltechAUTHORS:20200219-114918280", "isbn": "978-1-4020-0683-8", "book_title": "Recent Advances in Experimental Mechanics: In Honor of Isaac M. Daniel", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200219-114918280", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-95-1-0453" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Gdoutos-E-E", "name": { "family": "Gdoutos", "given": "Emmanuel E." } } ] }, "doi": "10.1007/0-306-48410-2_27", "pub_year": "2002", "author_list": "Rosakis, A. J.; Yu, C.; et el." }, { "id": "https://authors.library.caltech.edu/records/0x446-8q595", "eprint_id": 99190, "eprint_status": "archive", "datestamp": "2023-08-21 22:52:59", "lastmod": "2024-01-14 21:59:24", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Dimotakis-P-E", "name": { "family": "Dimotakis", "given": "Paul E." } } ] }, "title": "Challenges in Turbulent Mixing with Combustion", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Shear Layer; Direct Numerical Simulation; Turbulent Combustion; Scalar Dissipation Rate; Direct Numerical Simulation Result", "note": "\u00a9 2002 Springer Science+Business Media Dordrecht. \n\nI would like to acknowledge discussions with A. Cook, S. J. Chapman, and T. Mattner on the Rayleigh-Taylor instability, with H. Wang on the sensitivity to molecular transport coefficients, and the on-going work on the effects of volume viscosity with H. Lam. This paper and the recent experimental and computational work discussed was supported by AFOSR grants F49620-98-1-0052, F49620-00-1-0036, and F49620-01-1-0006, and DOE contract W-7405-ENG-48, which are gratefully acknowledged. Finally, I would like to thank A. Pollard for his gracious invitation to attend and contribute to this Symposium.", "abstract": "Turbulent combustion combines the complexities of turbulence and mixing, challenges not met in the twentieth century, with the complexity and subtlety of chemical kinetics. This discussion focuses on progress and some turbulent-mixing issues in chemically reacting flows stemming from experimental, modeling, and direct-numerical simulation (DNS) studies. The mixing transition will be discussed. DNS studies of the Rayleigh-Taylor instability in miscible fluids reveal an early-time diffusive growth and a strong sensitivity to initial conditions. Recent experiments address the assumption of isotropy in turbulence and mixing. Experiments in high-speed shear layers elucidate some effects of compressibility on the mixed-fluid field. Issues involving molecular-transport coefficients will also be discussed.", "date": "2002", "date_type": "published", "publisher": "Springer", "place_of_pub": "Dordrecht", "pagerange": "95-112", "id_number": "CaltechAUTHORS:20191009-111729565", "isbn": "978-90-481-6074-7", "book_title": "IUTAM Symposium on Turbulent Mixing and Combustion", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191009-111729565", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "F49620-98-1-0052" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "F49620-00-1-0036" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "F49620-01-1-0006" }, { "agency": "Department of Energy (DOE)", "grant_number": "W-7405-ENG-48" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Pollard-A", "name": { "family": "Pollard", "given": "A." } }, { "id": "Candel-S", "name": { "family": "Candel", "given": "S." } } ] }, "doi": "10.1007/978-94-017-1998-8_8", "pub_year": "2002", "author_list": "Dimotakis, Paul E." }, { "id": "https://authors.library.caltech.edu/records/ypr41-9rp58", "eprint_id": 63999, "eprint_status": "archive", "datestamp": "2023-08-19 08:47:12", "lastmod": "2024-01-13 16:39:48", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Burcsu-E", "name": { "family": "Burcsu", "given": "E." } }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "G." }, "orcid": "0000-0002-2912-0001" }, { "id": "Bhattacharya-K", "name": { "family": "Bhattacharya", "given": "K." }, "orcid": "0000-0003-2908-5469" } ] }, "title": "Observation of Domain Motion in Single-Crystal Barium Titanate under Combined Electromechanical Loading Conditions", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2002 Springer. \n\nWe gratefully acknowledge the support of the Army Research Office (M.A. Zikry, Program Manager) under grant DAAD 19-99-1-0319. This work was supported in part by the MRSEC Program of the National Science Foundation under Award Number DMR-0080065.", "abstract": "The nonlinear electromechanical behavior of ferroelectric materials is governed by the motion of domains. Since many common ferroelectric materials, such as barium titanate and PZT, are also ferroelastic, the domain motion is highly affected by stress as well as electric field. Experiments are performed on (001) and (100) oriented single crystals of barium titanate under combined electromechanical loading conditions. The crystal is subjected to a constant compressive stress (dead load) and an oscillating electric field along the [001] direction. Global deformation and polarization are measured as a function of electric field at different values of compressive stress. The use of semi-transparent electrodes and transmitted illumination allows in situ, real-time microscopic observations of domain patterns using a long working-distance, polarizing microscope. The combined electromechanical loading results in a cycle of stress and electric field induced 90\u00b0 domain switching. This is an electrostrictive behavior with measured strains of up to 0.9%.", "date": "2002", "date_type": "published", "publisher": "Springer", "place_of_pub": "New York, NY", "pagerange": "63-70", "id_number": "CaltechAUTHORS:20160127-085635071", "isbn": "978-90-481-6071-6", "book_title": "IUTAM Symposium on Mechanics of Martensitic Phase Transformation in Solids", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160127-085635071", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Army Research Office (ARO)", "grant_number": "DAAD 19-99-1-0319" }, { "agency": "NSF", "grant_number": "DMR-0080065" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Sun-Qing-Ping", "name": { "family": "Sun", "given": "Qing-Ping" } } ] }, "doi": "10.1007/978-94-017-0069-6_8", "pub_year": "2002", "author_list": "Burcsu, E.; Ravichandran, G.; et el." }, { "id": "https://authors.library.caltech.edu/records/h3cnd-vqd54", "eprint_id": 41288, "eprint_status": "archive", "datestamp": "2023-08-19 08:44:52", "lastmod": "2023-10-24 23:36:51", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Pereira-F", "name": { "family": "Pereira", "given": "F." } }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "M." }, "orcid": "0000-0003-0754-4193" }, { "id": "Dabiri-D", "name": { "family": "Dabiri", "given": "D." } }, { "id": "Modarress-D", "name": { "family": "Modarress", "given": "D." } } ] }, "title": "Instantaneous whole field measurement of velocity and size of air microbubbles in two-phase flows using DDPIV", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2002 Springer.\n\nThe visit of Dr. F. Pereira to the C.Q.V. was made possible by a fellowship of the\nFunda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia, Portugal. The research was supported\nby the Office of Naval Research (contract N00014-97-1-0303), under the direction\nof Dr. Edwin P. Rood and Dr. Mark Hyman. The Defocusing Digital Particle\nImage Velocimetry (DDPIV) technology is protected under a U.S. pending patent\nfiled by California Institute of Technology.", "abstract": "Defocusing digital particle image velocimetry (DDPIV) is the natural extension of\ndigital particle image velocimetry (DPIV), planar or quasi three-dimensional, to a true and unique\nthree-dimensional PIV technique. This work presents the defocusing optical concept by which the\ndepth information can be retrieved, thus overriding the limitation to in-plane measurements of\nactual PIV techniques, either standard or stereo-based. The concept is implemented into a three-dimensional\nimaging system specifically designed for the purpose of mapping two-phase bubbly\nflows. Digital images of the bubble field are recorded and analysed to provide information both on\nthe physical location of every single particle/bubble and on its respective size, which is estimated\nfrom the scattered light intensity. The calculation of the true three-component velocity field is\ndone by local spatial cross-correlation between two consecutive sets of particle/bubble locations.\nThe spatial resolution and uncertainty limits are established based on a simplified model of the\ndefocusing optical system. Accuracy measurements show that the average error on the\ndisplacements is about 0.02 pixels. The methodology used to measure the size is laid out by\napplication of the Mie scattering theory. A DDPIV prototype instrument was fabricated on specific\nrequirements. The instrument records high resolution images of the bubble field and is capable of\nproviding bubble size and bubble location within a cubic foot volume. The technique is applied to\nthe study of the dynamics of sub-millimeter air bubbles in a three-dimensional vertical flow\ngenerated by a propeller. Velocity, bubble size distribution and void fraction for these flows are\ndiscussed.", "date": "2002", "date_type": "published", "publisher": "Springer", "place_of_pub": "New York", "pagerange": "269-287", "id_number": "CaltechAUTHORS:20130912-105402726", "isbn": "9783540428374", "book_title": "Laser techniques for fluid mechanics", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130912-105402726", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia (FCT)" }, { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-97-1-0303" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Adrian-R-J", "name": { "family": "Adrian", "given": "R. J." } } ] }, "doi": "10.1007/978-3-662-08263-8_16", "pub_year": "2002", "author_list": "Pereira, F.; Gharib, M.; et el." }, { "id": "https://authors.library.caltech.edu/records/gsdnb-2cy80", "eprint_id": 63981, "eprint_status": "archive", "datestamp": "2023-08-19 07:59:55", "lastmod": "2024-01-13 16:32:25", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Burcsu-E", "name": { "family": "Burcsu", "given": "Eric" } }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "G." }, "orcid": "0000-0002-2912-0001" }, { "id": "Bhattacharya-K", "name": { "family": "Bhattacharya", "given": "Kaushik" }, "orcid": "0000-0003-2908-5469" } ] }, "title": "Electromechanical behavior of 90-degree domain motion in barium titanate single crystals", "ispublished": "unpub", "full_text_status": "public", "keywords": "ferroelectric crystals, barium titanate, domain switching, electrostriction", "note": "\u00a9 2001 Society of Photo-Optical Instrumentation Engineers. \n\nWe gratefully acknowledge the support of the Army Research Office (M.A. Zikry, Program Manager) under grant DAAD 19-99-1-0319. This work was supported in part by the MRSEC Program of the National Science Foundation under Award Number DMR-0080065.\n\nPublished - 121_1.pdf
", "abstract": "It is well known that many common ferroelectric materials are also ferroelastic, thus the nonlinear behavior of these materials, as governed by domain motion, is highly affected by stress, as well as electric field. The combined influence of stress and electric field on domain motion and the electrostrictive response of ferroelectric single crystals is investigated. Experiments are performed on (001) and (100) oriented single crystals of barium titanate under combined electro-mechanical loading. The crystal is exposed to a constant compressive stress and an oscillating electric field along the [001] direction. Global deformation and polarization are measured as a function of electric field at different values of compressive stress. The use of semi-transparent electrodes and transmitted illumination allow in situ, real-time microscopic observations of domain motion using a long working-distance, polarizing microscope. The combined electro-mechanical loading results in a cycle of stress and electric field induced 90-degree domain switching. The magnitude of the global deformation increases with stress, with maximum steady state actuation strain of 0.57%.", "date": "2001-07-11", "date_type": "published", "publisher": "Society of Photo-Optical Instrumentation Engineers", "place_of_pub": "Bellingham, WA", "pagerange": "121-130", "id_number": "CaltechAUTHORS:20160126-135845277", "isbn": "0-8194-4019-1", "book_title": "Smart Structures and Materials 2001: Active Materials: Behavior and Mechanics", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160126-135845277", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Army Research Office (ARO)", "grant_number": "DAAD 19-99-1-0319" }, { "agency": "NSF", "grant_number": "DMR-0080065" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Lynch-C-S", "name": { "family": "Lynch", "given": "Christopher S." } } ] }, "doi": "10.1117/12.432748", "primary_object": { "basename": "121_1.pdf", "url": "https://authors.library.caltech.edu/records/gsdnb-2cy80/files/121_1.pdf" }, "pub_year": "2001", "author_list": "Burcsu, Eric; Ravichandran, G.; et el." }, { "id": "https://authors.library.caltech.edu/records/asy7m-a7e51", "eprint_id": 91474, "eprint_status": "archive", "datestamp": "2023-08-19 06:11:15", "lastmod": "2024-01-14 21:15:21", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chasiotis-Ioannis", "name": { "family": "Chasiotis", "given": "Ioannis" }, "orcid": "0000-0001-6521-8332" }, { "id": "Knauss-W-G", "name": { "family": "Knauss", "given": "Wolfgang G." } } ] }, "title": "Microtensile tests with the aid of probe microscopy for the study of MEMS materials", "ispublished": "unpub", "full_text_status": "public", "keywords": "MEMS, polysilicon, tensile test, mechanical properties, UV adhesive grip, Atomic Force Microscopy, Digital Image Correlation, surface roughness", "note": "\u00a9 2000 Society of Photo-Optical Instrumentation Engineers (SPIE). \n\nThe authors gratefully acknowledge the support by the Airforce Office of Scientific Research (Round Robin Program) through grant F49629-97-1-0324, under the direction of Major Brian Sanders and grant F49620-99-1-0091, under Drs. T. Hahn and D. Segalman.\n\nPublished - 96.pdf
", "abstract": "Mechanical tests of thin films require novel and sophisticated methods that can address the geometry and microstructure of the films. A new method of micro-tensile testing of MicroElectroMechanical Systems (MEMS) films has been demonstrated. An improved apparatus has been designed and implemented to measure the elastic tensile properties. (Young's modulus, Poisson's ration and tensile strength) of surface micromachined polysilicon specimans. The tensile specimans are dog-bone shaped ending in a large paddle for convenient electrostatic or, in the improved apparatus, UV adhesive gripping. The test section of the specimens is 400\u00b5m long with 2\u00b5mx50\u00b5m cross section. The method employs Atomic Force Microscope (AFM) acquired surface topologies of deforming specimans to determine (fields of) strain by way of the Digital Image Correlation method (DIC). With this method, high strength of non- linearly behaving materials under different environmental conditions can be tested by measuring the strains directly on the surface of the film with nanometer resolution in in-place and out-of-plane measurements.", "date": "2000-08-11", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "96-103", "id_number": "CaltechAUTHORS:20181204-132724650", "isbn": "9780819438317", "book_title": "Materials and Device Characterization in Micromachining III", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181204-132724650", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "F49629-97-1-0324" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "F49620-99-1-0091" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Vladimirsky-Y", "name": { "family": "Vladimirsky", "given": "Yuli" } }, { "id": "Coane-P-J", "name": { "family": "Coane", "given": "Philip J." } } ] }, "doi": "10.1117/12.395616", "primary_object": { "basename": "96.pdf", "url": "https://authors.library.caltech.edu/records/asy7m-a7e51/files/96.pdf" }, "pub_year": "2000", "author_list": "Chasiotis, Ioannis and Knauss, Wolfgang G." }, { "id": "https://authors.library.caltech.edu/records/py5gp-bsx44", "eprint_id": 28266, "eprint_status": "archive", "datestamp": "2023-08-19 05:59:28", "lastmod": "2023-10-24 17:46:30", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Zarandi-M", "name": { "family": "Zarandi", "given": "M." } }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "M." } } ] }, "title": "Pulsatile flow in curved vessels", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2000 IEEE. Date of Current Version: 06 August 2002.", "abstract": "Three distinct secondary flow patterns are observed in the authors' experimental study. The first one is the known Dean flow, which is a double-circulation pattern. The second and the third patterns, which are discovered for the first time, are the clockwise and counterclockwise single-circulation patterns. The transition from one pattern to another is dependent on the spatial boundary conditions and independent of the temporal boundary conditions. The secondary flow velocity gradient and hence its shear stress is comparable to the axial flow velocity gradient and shear stress in the case of single circulation pattern. For the Dean flow or double-circulation secondary flow pattern, shear stress values are much less than those for the axial flow. This finding has potential pathological consequences.", "date": "2000-07", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "249-250", "id_number": "CaltechAUTHORS:20111201-092425965", "isbn": "0-7803-6466-X", "book_title": "Proceedings of the 22nd Annual International Conference of the IEEE Engineering in Medicine and Biology Society", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20111201-092425965", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "6880639", "name": "INSPEC Accession Number" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1109/IEMBS.2000.900718", "pub_year": "2000", "author_list": "Zarandi, M. and Gharib, M." }, { "id": "https://authors.library.caltech.edu/records/g7p4f-bgb71", "eprint_id": 41679, "eprint_status": "archive", "datestamp": "2023-08-19 05:55:43", "lastmod": "2024-01-13 06:04:32", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Burcsu-E", "name": { "family": "Burcsu", "given": "Eric" } }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "G." }, "orcid": "0000-0002-2912-0001" }, { "id": "Bhattacharya-K", "name": { "family": "Bhattacharya", "given": "K." }, "orcid": "0000-0003-2908-5469" } ] }, "title": "Mechanics of large electrostriction in ferroelectrics", "ispublished": "unpub", "full_text_status": "public", "keywords": "ferroelectric crystals, barium titanate, domain switching, electrostriction", "note": "\u00a9 2000 SPIE.\n\nWe greatfully acknowledge the support of the Army Research Office (M.A. Zikry, Program Manager) under grant #\nDAAD 19-99-1-0319. K.B. would also like to acknowledge the support of the Airforce Office of Scientific Research\nunder grant # MURI F49620-98-1-0433.\n\nPublished - Burcsu_2000p296.pdf
", "abstract": "The complex arrangement of domains observed in ferroelectric crystals is a consequence of multiple energy minima\nof the crystal free energy density. Since the total energy is a sum of the free energy, and electrical and mechanical\nwork, switching between the different energetically equivalent domain states can be achieved by both electrical and\nmechanical means. For many ferroelectric materials, this results in an electrostrictive phenomenon resulting from\ndomain switching. In the current study, the electrostrictive behavior of single crystal ferroelectric perovskites has\nbeen investigated experimentally. Experiments have been performed in which a crystal of barium titanate is exposed\nto a constant compressive stress and an oscillating electric field and global deformation is measured. The combined\nelectromechanical loading results in a cycle of stress and electric field induced 90-degree domain switching. The\ndomain switching cycle results in a measurable strain response theoretically limited by the crystallographic unit cell\ndimensions. Induced strains of more than 0.8% have been measured in barium titanate. Larger strains of up to 5%\nare predicted for other materials of the same class.", "date": "2000-06-14", "date_type": "published", "publisher": "International Society for Optical Engineering", "place_of_pub": "Bellingham, WA", "pagerange": "296-304", "id_number": "CaltechAUTHORS:20131004-100114192", "isbn": "0-8194-3610-0", "book_title": "Smart structures and materials 2000. Active materials, behavior and mechanics", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131004-100114192", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Army Research Office (ARO)", "grant_number": "DAAD 19-99-1-0319" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "F49620-98-1-0433" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Lynch-C", "name": { "family": "Lynch", "given": "Chris" } } ] }, "doi": "10.1117/12.388214", "primary_object": { "basename": "Burcsu_2000p296.pdf", "url": "https://authors.library.caltech.edu/records/g7p4f-bgb71/files/Burcsu_2000p296.pdf" }, "pub_year": "2000", "author_list": "Burcsu, Eric; Ravichandran, G.; et el." }, { "id": "https://authors.library.caltech.edu/records/58d3p-wsn86", "eprint_id": 95275, "eprint_status": "archive", "datestamp": "2023-08-21 20:45:15", "lastmod": "2023-10-20 19:04:21", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Leyva-I-A", "name": { "family": "Leyva", "given": "I. A." } }, { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "H. G." }, "orcid": "0000-0002-4903-8419" } ] }, "title": "Shock Detachment Process in Hypervelocity Flow over a Cone", "ispublished": "unpub", "full_text_status": "public", "keywords": "Shock detachment; Hypervelocity Flow; High Enthalpy; Nonequilibrium Cone Flows", "note": "\u00a9 2000 University of Southampton. \n\nThe authors would like to thank T5 members for helping to set up and run the experiments and Joe Olejniczak for providing the nonequilibrium code and endless help on its use.\n\nPublished - TR000560.pdf
", "abstract": "A comprehensive experimental and computational study of the shock detachment process in hypervelocity flow over cones is presented. The experiments are carried out in the T5 hypervelocity shock tunnel. The computations are mostly done with a code for axisymmetric thermo-chemical nonequilibrium flow. The data obtained confirm a previous theoretical model that predicts lower growth rate of the detachment distance with increasing cone half-angle for nonequilibrium flows than for frozen and equilibrium flows. The lower growth rate is related to the behavior of the sonic line in relaxing flows. The growth of the subsonic region is studied in detail from attached to detached conditions. A comparison between measured and computed interferograms is also made. Measured and computed heat flux distributions are compared, and differences between flows with attached and detached shocks are discussed.", "date": "2000", "date_type": "published", "publisher": "University of Southampton", "place_of_pub": "Southampton, United Kingdom", "pagerange": "1607-1612", "id_number": "CaltechAUTHORS:20190506-174243874", "isbn": "085432707X", "book_title": "Proceedings of the 22nd International Symposium on Shock Waves", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190506-174243874", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Ball-G-J", "name": { "family": "Ball", "given": "G. J." } }, { "id": "Hillier-R", "name": { "family": "Hillier", "given": "R." } }, { "id": "Roberts-G-T", "name": { "family": "Roberts", "given": "G. T." } } ] }, "doi": "10.7907/GRNB-AA64", "primary_object": { "basename": "TR000560.pdf", "url": "https://authors.library.caltech.edu/records/58d3p-wsn86/files/TR000560.pdf" }, "pub_year": "2000", "author_list": "Leyva, I. A. and Hornung, H. G." }, { "id": "https://authors.library.caltech.edu/records/hnran-m8n69", "eprint_id": 41543, "eprint_status": "archive", "datestamp": "2023-08-19 05:05:21", "lastmod": "2023-10-24 23:49:31", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Gharib-M-R", "name": { "family": "Gharib", "given": "M. R." } }, { "id": "Leonard-A", "name": { "family": "Leonard", "given": "A." } }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "M." } } ] }, "title": "A fluid force deduction technique for vibrating structures in cross-flow", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2000 Balkema.", "abstract": "An experimental technique is introduced for deducing the unsteady fluid forces, F(t), on elastically\nvibrating structures using their oscillation trace y(t) , and the free stream velocity U. This new technique\ninvolves an accurate modeling of the elastic structure as an ordinary differential equation and employing\ntime-dependent oscillation traces, y(t) and/or the acceleration a(t), to extract the side force on the structure.\nFiltering the oscillation signals and modeling the non-linear damping terms in the structural equation turn out\nto be the challenges of this technique. This technique may be applied in force studies relating vortex patterns\nand the the unsteady forces as well as methods for predicting or modeling fluid forces and amplitudes. Although\nthe results are not compared with any independent technique, the unsteady lift coefficient traces show\nhigh values of above three as observed by other researchers.", "date": "2000", "date_type": "published", "publisher": "Balkema", "place_of_pub": "Rotterdam", "pagerange": "85-89", "id_number": "CaltechAUTHORS:20130930-085939898", "isbn": "90-5809-129-5", "book_title": "Flow-induced vibration", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130930-085939898", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Ziada-S", "name": { "family": "Ziada", "given": "Samir" } }, { "id": "Staubli-T", "name": { "family": "Staubli", "given": "Thomas" } } ] }, "pub_year": "2000", "author_list": "Gharib, M. R.; Leonard, A.; et el." }, { "id": "https://authors.library.caltech.edu/records/nkgcy-fe128", "eprint_id": 41467, "eprint_status": "archive", "datestamp": "2023-08-19 05:05:13", "lastmod": "2023-10-24 23:45:59", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Gharib-M", "name": { "family": "Gharib", "given": "Morteza" } }, { "id": "Dabiri-D", "name": { "family": "Daribi", "given": "Dana" } } ] }, "title": "Digital Particle Image Velocimetry", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2000 World Scientific Publishing Company.", "abstract": "Particle Image Velocimetry (PIV) can be considered one of the most important\nachievements of flow diagnostic technologies in the modern history of fluid mechanics.\nIn this chapter, our intent is to provide a general understanding of the\nconcepts behind this powerful global quantitative flow visualization method as\nwell as some if its novel applications. Various technical aspects of digital particle\nimage velocimetry have been the subject of numerous papers and books\nin the available literature. Throughout this paper, some key references will be\nintroduced for the reader to consult for deeper exposure to the subject.", "date": "2000", "date_type": "published", "publisher": "World Scientific Publishing Company", "place_of_pub": "Singapore", "pagerange": "123-147", "id_number": "CaltechAUTHORS:20130923-092418330", "isbn": "9781848160361", "book_title": "Flow Visualization: Techniques and Examples", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130923-092418330", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Smits-A-J", "name": { "family": "Smits", "given": "Alexander J." } }, { "id": "Lim-T-T", "name": { "family": "Lim", "given": "T. T." } } ] }, "pub_year": "2000", "author_list": "Gharib, Morteza and Daribi, Dana" }, { "id": "https://authors.library.caltech.edu/records/jx7s7-jft50", "eprint_id": 20888, "eprint_status": "archive", "datestamp": "2023-08-19 04:44:35", "lastmod": "2023-10-20 23:33:51", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Seywert-C", "name": { "family": "Seywert", "given": "C." } }, { "id": "Culick-F-E-C", "name": { "family": "Culick", "given": "F. E. C." } } ] }, "title": "Some Influences of Noise on Combustion Instabilities and Combustor Dynamics", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1999, Jannaf. This work was supported partly by the California Institute of Technology; partly\nby the Caltech Multidisciplinary University Research Initiative under ONR Grant No. N00014-95-1-1338\n(Dr. Judah Goldwasser, Program Manager); partly by the Air Force Office of Scientific Research (Dr. Mitat\nBirkan, Program Manager); partly by ENEL (Dr. Giancarlo Benelli, Program Manager); and partly by the\nDepartment of Energy Advanced Gas Turbine Systems Research (AGTSR) Program under Subcontract No.\n98-02-SR072 (Dr. Larry Golan, Program Manager).", "abstract": "The chief purpose of this paper is to investigate the influences of noise, more generally stochastic\nsources of any sort, on linear and nonlinear unsteady motions in combustion chambers. To be definite,\nour primary applications here relate to combustion instabilities in solid propellant rockets, particularly\nlinear stability. Two aspects are especially relevant to practical applications: the direct effects of noise on\nstability; and extraction of information about stability margin from noisy pressure records taken for stable\nmotors. However, the formulation and results are relevant to combustors generally. A fundamental issue\nis the distinction between and relative importance of self-excited (linearly unstable) oscillations on the one\nhand and forced oscillation on the other. This has been a controversial and occasionally misunderstood\ntopic for many years. The essential ideas can be clarified unambiguously within the context of global\ndynamics treated here. We are not so concerned with the details of data processing as with the physical\ninterpretation of the results.", "date": "1999-10", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20101118-105039121", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20101118-105039121", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech Multidisciplinary University Research Initiative", "grant_number": "ONR N00014-95-1-1338" }, { "agency": "Air Force Office of Scientific Research (AFOSR)" }, { "agency": "ENEL" }, { "agency": "Department of Energy Advanced Gas Turbine Systems Research (AGTSR)", "grant_number": "98-02-SR072" } ] }, "other_numbering_system": { "items": [ { "name": "Guggenheim Jet Propulsion Center" } ] }, "local_group": { "items": [ { "id": "Guggenheim-Jet-Propulsion-Center" }, { "id": "GALCIT" } ] }, "pub_year": "1999", "author_list": "Seywert, C. and Culick, F. E. C." }, { "id": "https://authors.library.caltech.edu/records/ftxb1-71311", "eprint_id": 104382, "eprint_status": "archive", "datestamp": "2023-08-19 03:50:12", "lastmod": "2023-10-20 20:24:12", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Voelkl-T", "name": { "family": "Voelkl", "given": "T." } }, { "id": "Pullin-D-I", "name": { "family": "Pullin", "given": "D. I." } }, { "id": "Henderson-R-D", "name": { "family": "Henderson", "given": "R. D." } } ] }, "title": "The Stretched-Vortex SGS Model in Physical Space", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1999 Springer Science+Business Media Dordrecht. \n\nThis work was supported partially by the National Science Foundation under Grant CTS-9634222 and partially by the Academic Strategic Alliances Program of the Accelerated Strategic Computing Initiative (ASCII ASAP) under subcontract no. B341492 of DOE contract W-7405-ENG-48.", "abstract": "The stretched-vortex subgrid stress model for the large-eddy simulation of turbulent flows has been developed to the stage where it can be applied to realistic flow at large Reynolds numbers [1] [2]. The basic assumption of this model [3] is that the subgrid vortex structure consists of straight, stretched vortices containing a nearly axisymmetric subgrid vorticity field. Vortices of this type, such as the Burgers vortex and the stretched-spiral vortex have provided fair quantitative estimates of turbulence fine-scale properties [4]. These structures are probably an oversimplified model of fine-scale turbulence, but may nevertheless contain sufficient of the vortex-stretching and energy cascade physics characteristic of the small scales to provide a reasonable basis for subgrid-stress modelling for LES. The resulting subgrid stresses are\n\u03a4_(ij)=K(\u03b4_(ij)\u2212e^v_ie^v_j).\n(1)\nwhere K is the subgrid energy and e_i^ v , i = 1, 2, 3 are the direction cosines of the subgrid vortex axis. The local subgrid dissipation \u03f5_(sgs) is equal to the product of K with the component of S_(ij) aligned with the vortex axis. A class of simple models is obtained when it is assumed that the subgrid vortices are aligned with the eigenvectors of the rate-of-strain tensor S_(ij) [1]. Utilizing an assumed Kolmogorov form for the local subgrid energy spectrum, the model estimates the turbulent energy production at the resolved-scale cutoff in terms of the model parameters \u03f5 and the Kolmogorov prefactor K\u2080 and adjusts these parameters locally so as to continue the cascade through the cutoff to the subgrid vortex structures where the dissipation takes place.", "date": "1999", "date_type": "published", "publisher": "Springer", "place_of_pub": "Dordrecht", "pagerange": "459-464", "id_number": "CaltechAUTHORS:20200714-123705635", "isbn": "978-94-010-5924-4", "book_title": "Recent Advances in DNS and LES", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200714-123705635", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "CTS-9634222" }, { "agency": "Department of Energy (DOE)", "grant_number": "B341492" }, { "agency": "Department of Energy (DOE)", "grant_number": "W-7405-ENG-48" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Knight-D", "name": { "family": "Knight", "given": "Doyle" } }, { "id": "Sakell-L", "name": { "family": "Sakell", "given": "Leonidas" } } ] }, "doi": "10.1007/978-94-011-4513-8_39", "pub_year": "1999", "author_list": "Voelkl, T.; Pullin, D. I.; et el." }, { "id": "https://authors.library.caltech.edu/records/rbwrz-m0881", "eprint_id": 88782, "eprint_status": "archive", "datestamp": "2023-08-19 03:18:45", "lastmod": "2024-01-14 20:38:16", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chasiotis-Ioannis", "name": { "family": "Chasiotis", "given": "Ioannis" }, "orcid": "0000-0001-6521-8332" }, { "id": "Knauss-W-G", "name": { "family": "Knauss", "given": "Wolfgang G." } } ] }, "title": "Mechanical properties of thin polysilicon films by means of probe microscopy", "ispublished": "unpub", "full_text_status": "public", "keywords": "Polysilicon, tensile test, mechanical properties, electrostatic grip, Atomic Force Microscopy, Digital Image Correlation, surface roughness, stiction", "note": "\u00a9 1998 Society of Photo-Optical Instrumentation Engineers (SPIE). \n\nThe authors would like to acknowledge Dr. Y. C. Tai of Electrical Engineering Department at Caltech and his graduate student Xing Yang for their help in releasing process. This work has been supported in part by the Airforce Office of Scientific Research (Round Robin Program) through grant F 49629-97-1-0324, under the direction of Major Brian Sanders.\n\nPublished - 66.pdf
", "abstract": "A new method for tensile testing of thin films is being developed. An electrostatic grip apparatus was designed and implemented to measure the elastic and ultimate tensile properties (Young's modulus, Poisson's ratio and tensile strength) of surface micromachined polysilicon specimens. The tensile specimens are 'dog-bone' shaped ending in a large 'paddle' for electrostatic gripping. The test section of the specimens is 400 micrometers long and with 2 micrometer X 50 micrometer cross section. The method employs Atomic Force Microscope (AFM) or Scanning Tunneling Microscope (STM) acquired surface topologies of deforming specimens to determine (fields of) strains. By way of the method of Digital Image Correlation (DIC), the natural surface roughness features are used as distributed markers. The effect of markers artificially deposited on the surface is examined computationally. Also the significance of other parameters on property measurements, such as surface roughness, has been examined computationally. Initial results obtained using the tensile test apparatus are presented.", "date": "1998-09-01", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "66-75", "id_number": "CaltechAUTHORS:20180813-091037460", "isbn": "9780819429711", "book_title": "Materials and Device Characterization in Micromachining", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180813-091037460", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "F 49629-97-1-0324" } ] }, "collection": "CaltechAUTHORS", "local_group": { "items": [ { "id": "GALCIT", "value": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Friedrich-C-R", "name": { "family": "Friedrich", "given": "Craig R." } }, { "id": "Vladimirsky-Y", "name": { "family": "Vladimirsky", "given": "Yuli" } } ] }, "doi": "10.1117/12.324072", "primary_object": { "basename": "66.pdf", "url": "https://authors.library.caltech.edu/records/rbwrz-m0881/files/66.pdf" }, "pub_year": "1998", "author_list": "Chasiotis, Ioannis and Knauss, Wolfgang G." }, { "id": "https://authors.library.caltech.edu/records/5ck70-j6f85", "eprint_id": 83864, "eprint_status": "archive", "datestamp": "2023-08-19 02:15:58", "lastmod": "2023-10-18 14:26:32", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ortiz-M", "name": { "family": "Ortiz", "given": "Michael" }, "orcid": "0000-0001-5877-4824" }, { "id": "Phillips-R", "name": { "family": "Phillips", "given": "Rob" }, "orcid": "0000-0003-3082-2809" } ] }, "title": "Nanomechanics of Defects in Solids", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1999 Academic Press. \n\nIt is our special pleasure to acknowledge fruitful collaborations with Ron Miller, David Rodney, Vijay Shenoy, and Ellad Tadmor. Tadmor's Ph.D. thesis laid the groundwork for all subsequent efforts on the quasicontinuum method and included the first applications to the problem of nanoindentation. Shenoy developed the version of the quasicontinuum method in which multiple grains could be accounted for simultaneously, whereas Rodney created the first three-dimensional version of the code. We are also grateful to the AFOSR which funded much of this work through Grant F49620-95-I-0264 and the NSF which supported much of this work under Grants CMS-9414648 and DMR-9632524.", "abstract": "This chapter examines different aspects of nanomechanics of defects in solids. The methods by which the classical boundary-value problems of continuum mechanics can be imbued with atomistic content are reviewed. Microscopic modeling is founded on the fundamental assertion that beneath the details of observed macroscopic phenomenology, there is a set of microscopic processes which, when understood, rationalize the observed macroscopic behavior to the extent of enabling quantitative predictions. The microscopic simulation of materials is based on the evolution of degrees of freedom that are governed by the Schrodinger equation. It is found that either phenomenologically, or through explicit calculational strategies, the electronic degrees of freedom is implicitly subsumed in the effective pair potential. Once the pair potential has been identified, it is a straightforward matter to evaluate radial derivatives and the corresponding force fields. The energy associated with each distortion may be computed explicitly by recourse to direct atomistics. The contribution due to slip may be extracted by subtracting off the bulk elastic energy. As a result, the exact misfit energy is determined from atomistics. The cohesive-zone theories applied to fracture are also elaborated.", "date": "1998", "date_type": "published", "publisher": "Academic Press", "place_of_pub": "San Diego, CA", "pagerange": "1-79", "id_number": "CaltechAUTHORS:20171213-092247784", "isbn": "978-0-12-002036-2", "book_title": "Advances in Applied Mechanics", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171213-092247784", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "F49620-95-I-0264" }, { "agency": "NSF", "grant_number": "CMS-9414648" }, { "agency": "NSF", "grant_number": "DMR-9632524" } ] }, "collection": "CaltechAUTHORS", "local_group": { "items": [ { "id": "GALCIT", "value": "GALCIT" } ] }, "contributors": { "items": [ { "id": "van-der-Giessen-E", "name": { "family": "van der Giessen", "given": "Erik" } }, { "id": "Wu-T-Y-T", "name": { "family": "Wu", "given": "Theodore Y." } } ] }, "doi": "10.1016/S0065-2156(08)70184-4", "pub_year": "1998", "author_list": "Ortiz, Michael and Phillips, Rob" }, { "id": "https://authors.library.caltech.edu/records/0jnxk-hhn26", "eprint_id": 104409, "eprint_status": "archive", "datestamp": "2023-08-22 12:29:12", "lastmod": "2023-10-20 20:25:51", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Knauss-W-G", "name": { "family": "Knauss", "given": "W. G." } } ] }, "title": "Volume/Shear Interaction in Glassy Polymers", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Glass Transition Temperature; Creep Rate; Maximum Shear Stress; Shear Behavior; Glassy Polymer", "note": "\u00a9 1998 Springer-Verlag Berlin Heidelberg.", "abstract": "It has been demonstrated in the past that the nonlinear time- or rate-dependent shear behavior of glassy polymers is susceptible to volumetric changes. Following from models based on free volume effects in the glass transition range it has been shown analytically that many effects of nonlinear behavior could possibly be traced to volumetric changes and associated dilatational internal clock mechanisms.", "date": "1998", "date_type": "published", "publisher": "Springer-Verlag", "place_of_pub": "Heidelberg", "pagerange": "21", "id_number": "CaltechAUTHORS:20200716-135556381", "isbn": "978-3-642-51064-9", "book_title": "Progress and Trends in Rheology V", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200716-135556381", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Emri-I", "name": { "family": "Emri", "given": "I." } } ] }, "doi": "10.1007/978-3-642-51062-5_7", "pub_year": "1998", "author_list": "Knauss, W. G." }, { "id": "https://authors.library.caltech.edu/records/cd3d9-kbe54", "eprint_id": 21914, "eprint_status": "archive", "datestamp": "2023-08-19 01:51:19", "lastmod": "2024-01-13 00:09:07", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Roh-T-S", "name": { "family": "Roh", "given": "T. S." } }, { "id": "Culick-F-E-C", "name": { "family": "Culick", "given": "F. E. C." } } ] }, "title": "Numerical study of acoustic oscillations and combustion instabilities in solid propellant rocket", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 1997. This work has been partially supported by the Caltech Multidisciplinary University Research Initiative\nunder ONR Grant No. N00014-95-1-1338; Dr. Richard S. Miller of the Office of Naval Research is Program Manager. Approved for public release; distribution is unlimited.\n\nSubmitted - 392_Roh_TS_1997.pdf
", "abstract": "A numerical analysis of unsteady motions in solid rocket motors has been conducted. A fully coupled\nimplicit scheme based on a dual time-stepping integration algorithm has been adopted to solve the governing\nequations and associated boundary conditions. A narrow pressure pulse is imposed at the head end to\nsimulate unsteady acoustic oscillations in the combustion chamber. Pressure increases when the front of the\npulse reaches near the nozzle area. Self-generated oscillations with frequency of standing wave propagates\nupstream in the combustion chamber. Investigation of transient response of gas-phase dynamics to traveling\npressure wave and its effects on propellant combustion reveals several aspects: Combustion responses have\na strong relationship with vorticity fluctuations in case of high turbulent intensity on the propellant surface.\nTemperature fluctuations of the propellant surface in the head end region seem to be very unstable and\nindependent of the pressure wave. Surface temperature without turbulence effect looks more sensitive to\ntemperature fluctuations in the primary flame zone. Stability of surface temperature is strongly related to\nturbulent intensity on the propellant surface.", "date": "1997-10", "date_type": "published", "publisher": "Chemical Propulsion Information Agency", "id_number": "CaltechAUTHORS:20110128-075156436", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110128-075156436", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech Multidisciplinary University Research Initiative", "grant_number": "ONR N00014-95-1-1338" } ] }, "other_numbering_system": { "items": [ { "name": "Guggenheim Jet Propulsion Center" } ] }, "local_group": { "items": [ { "id": "Guggenheim-Jet-Propulsion-Center" }, { "id": "GALCIT" } ] }, "primary_object": { "basename": "392_Roh_TS_1997.pdf", "url": "https://authors.library.caltech.edu/records/cd3d9-kbe54/files/392_Roh_TS_1997.pdf" }, "pub_year": "1997", "author_list": "Roh, T. S. and Culick, F. E. C." }, { "id": "https://authors.library.caltech.edu/records/aj1wf-adt86", "eprint_id": 41307, "eprint_status": "archive", "datestamp": "2023-08-19 00:44:32", "lastmod": "2024-03-05 16:52:11", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Dabiri-D", "name": { "family": "Dabiri", "given": "Dana" } }, { "id": "Zhang-X", "name": { "family": "Zhang", "given": "Xin" } }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "Morteza" }, "orcid": "0000-0003-0754-4193" } ] }, "title": "Quantitative Visualization of Three-Dimensional Free Surface Slopes and Elevations", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1997 CRC Press.\n\nThe authors would like to thank Ed Rood and the Office of Naval Research Fluid Dynamics\nProgram for supporting this work (ONR-URI, Grant No. N00014-92-J-1610).", "abstract": "A new technique that integrates optics, colorimetry, and digital image\nprocessing is developed to measure the three-dimensional surface slope and elevation\nfor time-evolving flows. The setup requires that a lens be placed at a distance of its\nfocal length away from a diffuse, uniform, white light source which is covered with\nan appropriate transparent color palette. This setup then produces a system of color\nrays where beams of the same color are parallel to themselves, yet oriented in\ndifferent directions with respect to beams of other colors. This arrangement is used\nin one of two modes. In the first mode, the reflective mode, the arrangement is set\nto illuminate the free surface from above the free surface. A three-chip color camera\nplaced far above the free surface captures the reflected rays from the free surface\n(hence the name reflective mode). In the second mode, the refractive mode, the\narrangement illuminates the free surface from below the free surface. A three-chip\ncolor camera placed far above the free surface captures the refracted rays from the\nfree surface (hence the name refractive mode). For both modes, each of the three\nRGB color signals from the color camera is recorded onto separate laser disk\nrecorders. These modes then allow for measurements of the free surface slope by\ncreating a one-to-one correspondence between different colors and the free surface\nslopes. These data can then be integrated to derive the free surface elevation.\nApplications to various problems are discussed.", "date": "1997", "date_type": "published", "publisher": "CRC Press", "place_of_pub": "Boca Raton, FL", "pagerange": "1-21", "id_number": "CaltechAUTHORS:20130913-081844588", "isbn": "9780849326578", "book_title": "Atlas of Visualization III", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130913-081844588", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR-URI)", "grant_number": "N00014-92-J-1610" } ] }, "collection": "CaltechAUTHORS", "local_group": { "items": [ { "id": "GALCIT", "value": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Gakkai-K-J", "name": { "family": "Gakkai", "given": "Kashika J\u014dh\u014d" } } ] }, "pub_year": "1997", "author_list": "Dabiri, Dana; Zhang, Xin; et el." }, { "id": "https://authors.library.caltech.edu/records/c33gk-64k25", "eprint_id": 106862, "eprint_status": "archive", "datestamp": "2023-08-22 11:29:22", "lastmod": "2024-01-15 18:15:33", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Rosakis-A-J", "name": { "family": "Rosakis", "given": "A. J." }, "orcid": "0000-0003-0559-0794" }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "G." }, "orcid": "0000-0002-2912-0001" }, { "id": "Zhou-M", "name": { "family": "Zhou", "given": "M." } } ] }, "title": "Dynamically Growing Shear Bands in Metals: A Study of Transient Temperature and Deformation Fields", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Shear Band; Impact Velocity; Adiabatic Shear Band; Dynamic Crack Propagation; Length History", "note": "\u00a9 1997 Springer Science+Business Media Dordrecht. \n\nThe authors gratefully acknowledge support from the Army Research Office through grant No. DAAH 04-93-G0037 under Dr. K. Iyer. We are also grateful to Dr. Y. Rajapakse for support from the Office of Naval Research through grant No. N00014-90-J-1340. The computations were carried out on a Cray C98 computer at the Goddard Space Center and a Cray Y-MP2E/232 computer at the Jet Propulsion Laboratory. Many helpful discussions with Prof. M. Ortiz of Caltech are also acknowledged.", "abstract": "The objective of our work is (1) to establish the critical conditions for initiation and growth of shear bands in pre-notched plates subjected to asymmetric impact loading (dynamic mode II, see Fig. 1); and (2) to investigate and characterize the transition in the modes of failure when such plates are subjected to a variety of loading rates (impact velocities). These failure modes which may feature either dynamic shear band growth, dynamic crack propagation or both, (see Fig. 1), have been observed in structural materials such as the high strength steels and heat-resistant titanium alloy considered in the present work. The approach is to study both the dynamic mechanical deformations and the processes of heat generation and thermal softening. This necessitates the simultaneous use of high speed optical and infrared diagnostics in the experiments. In parallel to the experimental study, full-scale thermomechanical finite element simulations are conducted to assist the development of criteria for shear band initiation and propagation. The calculations make use of constitutive parameters measured in house through material testing in a variety of strain rates. Such a combined experimental and numerical approach enables us to make direct comparisons between measurements and predictions obtained using various material constitutive and failure models.", "date": "1997", "date_type": "published", "publisher": "Springer", "place_of_pub": "Dordrecht", "pagerange": "141-150", "id_number": "CaltechAUTHORS:20201201-105030731", "isbn": "978-94-010-6379-1", "book_title": "IUTAM Symposium on Nonlinear Analysis of Fracture", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201201-105030731", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Army Research Office (ARO)", "grant_number": "DAAH 04-93-G0037" }, { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-90-J-1340" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Willis-J-R", "name": { "family": "Willis", "given": "J. R." } } ] }, "doi": "10.1007/978-94-011-5642-4_14", "pub_year": "1997", "author_list": "Rosakis, A. J.; Ravichandran, G.; et el." }, { "id": "https://authors.library.caltech.edu/records/4gb8w-gdf75", "eprint_id": 83881, "eprint_status": "archive", "datestamp": "2023-08-19 00:50:07", "lastmod": "2023-10-18 14:27:55", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Gioia-Gustavo", "name": { "family": "Gioia", "given": "Gustavo" } }, { "id": "Ortiz-M", "name": { "family": "Ortiz", "given": "Michael" }, "orcid": "0000-0001-5877-4824" } ] }, "title": "Delamination of Compressed Thin Films", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1997 Academic Press. \n\nThis work has been funded by the National Science Foundation through\nBrown University's Materials Research Group on \"Micro-Mechanics of\nFailure Resistant Materials.\" We are grateful to Ashraf F. Bastawros of\nBrown University for making available to us the unpublished micrograph\nin Figure 8.", "abstract": "In this article, we specifically concern ourselves with the buckling-driven delamination mechanism, whereby a portion of the film buckles away from the substrate, thereby forming a blister (also termed buckle or wrinkle). Blisters may grow by interfacial fracture, a process which, under the appropriate conditions, may result in the catastrophic failure of the component. Blisters are often observed to adopt convoluted-even bizarre shapes and to fold into intricate patterns. A principal objective of this article is to review some recent developments based on the use of direct methods of the calculus of variations which have proven useful for understanding the mechanics of folding of thin films (Ortiz and Gioia, 1994). These developments are reviewed in Section III, which is extracted from the original publication. The remaining sections are devoted to the application of these principles to the problem of predicting the shape of thin-film blisters.", "date": "1997", "date_type": "published", "publisher": "Academic Press", "place_of_pub": "San Diego, CA", "pagerange": "119-192", "id_number": "CaltechAUTHORS:20171213-102407537", "isbn": "978-0-12-002033-1", "book_title": "Advances in Applied Mechanics", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171213-102407537", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Hutchinson-J-W", "name": { "family": "Hutchinson", "given": "John W." } }, { "id": "Wu-T-Y-T", "name": { "family": "Wu", "given": "Theodore Y." } } ] }, "doi": "10.1016/S0065-2156(08)70386-7", "pub_year": "1997", "author_list": "Gioia, Gustavo and Ortiz, Michael" }, { "id": "https://authors.library.caltech.edu/records/t2pkr-xgh21", "eprint_id": 20919, "eprint_status": "archive", "datestamp": "2023-08-19 00:32:45", "lastmod": "2023-10-20 23:35:25", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Culick-F-E-C", "name": { "family": "Culick", "given": "F. E. C." } }, { "id": "Roh-T-S", "name": { "family": "Roh", "given": "T. S." } } ] }, "title": "Applications of Various Methods of Analysis to Combustion Instabilities in Solid Propellant Rockets", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 1996, Japan Aerospace Exploration Agency. This work was partly sponsored by the California Institute of Technology and partly by the\nCaltech Multidisciplinary University Research Initiative under ONR Grant No. N00014-95-1-1338. Dr. Richard S. Miller of the Office of Naval Research is Program Manager.\n\nPublished - 333724a.pdf
Submitted - 386_Culick_FE_1996.pdf
", "abstract": "Instabilities of motions in a combustion chamber are consequences of the coupled dynamics of\ncombustion processes and of the flow in the chamber. The extreme complexities of the problem\nalways require approximations of various sorts to make progress in understanding the\nmechanisms and behavior of combustion instabilities. This paper covers recent progress in the\nsubject, mainly summarizing efforts in two areas: approximate analysis based on a form of\nGalerkin's method, particularly useful for understanding the global linear and nonlinear\ndynamics of combustion instabilities and numerical simulations intended to accommodate as\nfully as possible fundamental chemical processes in both the condensed and gaseous phases.\nOne purpose of current work is to bring closer together these approaches to produce more\ncomprehensive and detailed realistic results applicable to the interpretation of observations\nand for design of new rockets for both space and military applications. Particularly important\nare the goals of determining the connections between chemical composition and instabilities;\nand the influences of geometry on nonlinear behavior.", "date": "1996-11-01", "date_type": "published", "publisher": "Japan Aerospace Exploration Agency", "id_number": "CaltechAUTHORS:20101119-113430324", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20101119-113430324", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech Multidisciplinary University Research Initiative", "grant_number": "N00014-95-1-1338" } ] }, "other_numbering_system": { "items": [ { "id": "653", "name": "CPIA Publication" } ] }, "local_group": { "items": [ { "id": "Guggenheim-Jet-Propulsion-Center" }, { "id": "GALCIT" } ] }, "primary_object": { "basename": "333724a.pdf", "url": "https://authors.library.caltech.edu/records/t2pkr-xgh21/files/333724a.pdf" }, "related_objects": [ { "basename": "386_Culick_FE_1996.pdf", "url": "https://authors.library.caltech.edu/records/t2pkr-xgh21/files/386_Culick_FE_1996.pdf" } ], "pub_year": "1996", "author_list": "Culick, F. E. C. and Roh, T. S." }, { "id": "https://authors.library.caltech.edu/records/rh141-ctf45", "eprint_id": 41600, "eprint_status": "archive", "datestamp": "2023-08-20 06:54:39", "lastmod": "2023-10-24 23:52:47", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Gharib-M", "name": { "family": "Gharib", "given": "Mory" } } ] }, "title": "New trends and directions in quantitative flow visualization methods", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1996 TAPPI Press.", "abstract": "Visualization, in its various forms, has always contributed to\nendeavors of art, science and engineering. Tapping a\nremarkable means of the human brain to grasp complexity, it\nhas helped practitioners in all three endeavors achieve a better\nunderstanding of aesthetic, natural and technological objects,\nphenomena and processes. In science and engineering,\nwherever adequate visualization has been part of the creative\nprocess, it has yielded new insights into complex phenomena\nand catalyzed better descriptions and predictive models.\nExamples range from unmanned space exploration, weather\nsatellites, astronomy, the impetus for the recent advances in\nour understanding of turbulence, complicated industrial\nprocesses to aerodynamics, and all kinds of in vivo and in vitro\nmedical imaging applications. Usually, the nature of this\nunderstanding is qualitative; therefore, a subsequent\nquantitative measurement is essential for further progress.\nQuantitative single point measurement techniques such as hot\nwire anemometry or laser Doppler velocimetry are often used\nto obtain Eulerian velocity fields. These two techniques are\ntypically limited to simultaneous sampling at a few spatial\nlocations. In this respect, the global nature of the information\ncontained in a single flow image invites one to develop\nquantitative methods to obtain multi-point spatial and\ntemporal velocity or vorticity fields from such images. Indeed,\nsubstantial progress in many complex fields of science and\ntechnology has often awaited the development of adequate,\nquantitative-imaging methods capable of revealing global\ninformation about the phenomena understudy. In this talk, we\nfocus on the strive to advance present state-of-the-art,\nquantitative imaging.", "date": "1996", "date_type": "published", "publisher": "Technical Association of the Pulp and Paper Industry", "place_of_pub": "Atlanta, GA", "pagerange": "19", "id_number": "CaltechAUTHORS:20131002-091605663", "isbn": "0-89852-668-X", "book_title": "1996 Engineering Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131002-091605663", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "pub_year": "1996", "author_list": "Gharib, Mory" }, { "id": "https://authors.library.caltech.edu/records/9h4at-43c55", "eprint_id": 21916, "eprint_status": "archive", "datestamp": "2023-08-20 06:52:33", "lastmod": "2024-01-13 00:09:09", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Culick-F-E-C", "name": { "family": "Culick", "given": "F. E. C." } } ] }, "title": "Combustion instabilities in propulsion systems", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1996 Kluwer Academic Publishers.", "abstract": "The purpose of this paper is to give a broad overview of the field of combustion instabilities in propulsion systems. Virtually all of the material included here has appeared elsewhere, either in primary research reports or in reviews. None of the propulsion systems are covered in great detail, but sufficiently to establish the fundamental point that while there are obvious practical\ndifferences among the systems, for understanding and treating combustion instabilities, much is to be gained by treating the various phenomena within a common framework. In that context, the systems are distinguished chiefly by geometry and the kinds of propellants used. On that basis, a general framework can be constructed to serve both practical and theoretical purposes.", "date": "1996", "date_type": "published", "publisher": "Kluwer Academic Publishers", "place_of_pub": "Boston", "pagerange": "173-241", "id_number": "CaltechAUTHORS:20110128-112158907", "isbn": "978-0-7923-3888-8", "book_title": "Unsteady Combustion", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110128-112158907", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "name": "Guggenheim Jet Propulsion Center" } ] }, "local_group": { "items": [ { "id": "Guggenheim-Jet-Propulsion-Center" }, { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Culick-F-E-C", "name": { "family": "Culick", "given": "F. E. C." } }, { "id": "Heitor-M-V", "name": { "family": "Heitor", "given": "Manuel V." } }, { "id": "Whitelaw-J-H", "name": { "family": "Whitelaw", "given": "James H." } } ] }, "pub_year": "1996", "author_list": "Culick, F. E. C." }, { "id": "https://authors.library.caltech.edu/records/yyths-79s58", "eprint_id": 87140, "eprint_status": "archive", "datestamp": "2023-08-20 06:30:33", "lastmod": "2024-01-14 20:14:53", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Corvasce-C", "name": { "family": "Corvasce", "given": "C." } }, { "id": "Spagnolo-V", "name": { "family": "Spagnolo", "given": "V." } }, { "id": "Scamarcio-G", "name": { "family": "Scamarcio", "given": "G." } }, { "id": "Lugar\u00e0-M", "name": { "family": "Lugar\u00e0", "given": "M." } }, { "id": "Adduci-F", "name": { "family": "Adduci", "given": "F." } }, { "id": "Ferrara-M", "name": { "family": "Ferrara", "given": "M." } }, { "id": "Sibilano-M", "name": { "family": "Sibilano", "given": "M." } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "S." }, "orcid": "0000-0001-9373-3278" }, { "id": "Del-Guidice-M", "name": { "family": "Del Guidice", "given": "M." } }, { "id": "Re-M-G", "name": { "family": "Re", "given": "M. G." } } ] }, "title": "Quantum-well-laser mirror degradation investigated by microprobe optical spectroscopy", "ispublished": "unpub", "full_text_status": "public", "keywords": "diode laser, catastrophic optical damage (COD), Raman micro-probe spectroscopy, photoluminescence micro-probe spectroscopy", "note": "\u00a9 1995 Society of Photo-Optical Instrumentation Engineers (SPIE). \n\nThis work has been partially supported by Italian CNR (Research National Council).\n\nPublished - 360.pdf
", "abstract": "A study of facet degradation of InGaAs quantum well lasers is reported. We tune up a Raman and photoluminescence micro-probe technique for determining the crystal structure and the temperature profile of the cladding layer, in steps of approximately 1 micrometer, with a temperature resolution better than 1 degree Kelvin. The cladding layer composition and cross- section temperature profile have been monitored during operation. A clear correlation between the facet degradation and the type of protective coating is found.", "date": "1995-11-03", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "360-364", "id_number": "CaltechAUTHORS:20180614-161010885", "isbn": "0819420212", "book_title": "International Conference on Optical Diagnostics of Materials and Devices for Opto-, Micro-, and Quantum Electronics", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180614-161010885", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Consiglio Nazionale delle Ricerche (CNR)" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Svechnikov-S-V", "name": { "family": "Svechnikov", "given": "Sergey V." } }, { "id": "Valakh-M-Ya", "name": { "family": "Valakh", "given": "Mikhail Ya." } } ] }, "doi": "10.1117/12.226195", "primary_object": { "basename": "360.pdf", "url": "https://authors.library.caltech.edu/records/yyths-79s58/files/360.pdf" }, "pub_year": "1995", "author_list": "Corvasce, C.; Spagnolo, V.; et el." }, { "id": "https://authors.library.caltech.edu/records/f7zft-8k719", "eprint_id": 79693, "eprint_status": "archive", "datestamp": "2023-08-22 10:12:42", "lastmod": "2023-10-26 17:02:23", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "B\u00e9langer-J", "name": { "family": "B\u00e9langer", "given": "J." } }, { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "H." }, "orcid": "0000-0002-4903-8419" } ] }, "title": "Transverse Jet Mixing and Combustion Experiments in the Hypersonic Shock Tunnel T5 at GALCIT", "ispublished": "unpub", "full_text_status": "public", "keywords": "SCRAM-Jet engine; Hydrogen combustion; Hypervelocity flow", "note": "\u00a9 1995 Springer-Verlag Berlin Heidelberg.", "abstract": "For ground simulation of the flows that occur in SCRAM-Jet propulsion of hyper-velocity vehicles in which the hydrogen fuel is used as a coolant, it is essential that not only the enthalpy and pressure of the air flow, but also that the pressure and speed of the hydrogen be reproduced. Both can be achieved in the free-piston shock tunnel T5 together with the new small, combustion-heated hydrogen injection shock tunnel at GALCIT. Critical elements that need to be examined are the combustion efficiency and the turbulent mixing rate, especially at the unavoidable zero-shear condition, where the fuel and air speeds are the same. Results are presented from tests with a simple configuration consisting of a rectangular duct in which the injection system was mounted flush with one of the walls. The conditions cover a range of pressures from low values chosen to match previous experiments with the same duct from the HYPULSE expansion tube facility at the General Applied Sciences Laboratory, to values corresponding to the conditions closer to those in a real SCRAM-Jet engine.", "date": "1995", "date_type": "published", "publisher": "Springer", "place_of_pub": "Berlin", "pagerange": "157-162", "id_number": "CaltechAUTHORS:20170801-132303710", "isbn": "978-3-642-78831-4", "book_title": "Shock Waves @ Marseille I - Hypersonics, Shock Tube & Shock Tunnel Flow", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170801-132303710", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Brun-R", "name": { "family": "Brun", "given": "Raymond" } }, { "id": "Dumitrescu-L-Z", "name": { "family": "Dumitrescu", "given": "Lucien Z." } } ] }, "doi": "10.1007/978-3-642-78829-1_25", "pub_year": "1995", "author_list": "B\u00e9langer, J. and Hornung, H." }, { "id": "https://authors.library.caltech.edu/records/zazfc-kz558", "eprint_id": 106260, "eprint_status": "archive", "datestamp": "2023-08-20 05:12:03", "lastmod": "2023-10-20 23:17:17", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Liu-Charles-T", "name": { "family": "Liu", "given": "C. T." }, "orcid": "0000-0002-4314-8713" }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "G." }, "orcid": "0000-0002-2912-0001" } ] }, "title": "Effect of Loading Rate on Crack Tip Behavior- An Experimental and Numerical Investigation", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 Springer-Verlag Berlin Heidelberg 1995. \n\nWe gratefully acknowledge the support of the Air Force Office of Scientific Research and the encouragement of the technical monitor Dr. Walter Jones.", "abstract": "During the past few years, a considerable amount of research has been performed in the field of fracture and crack growth in highly filled polymeric materials [1\u20136]. Since these materials behave like viscoelastic materials, the fracture behavior near the crack tip can be strongly influenced by loading rate, temperature and constitutive behavior. In order to obtain a better understanding of the fracture behavior near the crack tip, knowledge of the displacement, strain and stress fields near the crack tip is indispensable.", "date": "1995", "date_type": "published", "publisher": "Springer Berlin Heidelberg", "place_of_pub": "Berlin, Heidelberg", "pagerange": "2063-2068", "id_number": "CaltechAUTHORS:20201023-102058758", "isbn": "9783642796562", "book_title": "Computational Mechanics '95: Theory and Applications", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201023-102058758", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Atluri-S-N", "name": { "family": "Atluri", "given": "S. N." } }, { "id": "Yagawa-G", "name": { "family": "Yagawa", "given": "G." } }, { "id": "Cruse-T", "name": { "family": "Cruse", "given": "Thomas" } } ] }, "doi": "10.1007/978-3-642-79654-8_343", "pub_year": "1995", "author_list": "Liu, C. T. and Ravichandran, G." }, { "id": "https://authors.library.caltech.edu/records/c7ea0-5th34", "eprint_id": 106636, "eprint_status": "archive", "datestamp": "2023-08-20 05:12:31", "lastmod": "2023-10-20 23:39:25", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Sanderson-S-R", "name": { "family": "Sanderson", "given": "S. R." } }, { "id": "Sturtevant-B", "name": { "family": "Sturtevant", "given": "B." } } ] }, "title": "Shock wave interactions in hypervelocity flow", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Shock-on-shock interaction, Shock impingement, Hypervelocity flow", "note": "\u00a9 Springer-Verlag Berlin Heidelberg 1995. \n\nThis work was supported by the Air Force Office of Scientific Research under Grant No. F 49620-92-J-0110.", "abstract": "The impingement of shock waves on blunt bodies in steady supersonic flow is known to cause extremely high local heat transfer rates and surface pressures. Although these problems have been studied in cold hypersonic flow, the effects of dissociative relaxation processes are unknown. In this paper we report a model aimed at determining the boundaries of the possible interaction regimes for an ideal dissociating gas. Local analysis about shock wave intersection points in the pressure-flow deflection angle plane with continuation of singular solutions is the fundamental tool employed. Further, we discuss an experimental investigation of the nominally two-dimensional mean flow that results from the impingement of an oblique shock wave on the leading edge of a cylinder. The effects of variations in shock impingement geometry were visualized using differential interferometry. Generally, real gas effects are seen to increase the range of shock impingement points for which enhanced heating occurs. They also reduce the type IV (Edney 1968 a,b) interaction supersonic jet width and influence the type II-III transition process.", "date": "1995", "date_type": "published", "publisher": "Springer Berlin Heidelberg", "place_of_pub": "Berlin, Heidelberg", "pagerange": "69-74", "id_number": "CaltechAUTHORS:20201111-190742416", "isbn": "9783642788314", "book_title": "Shock Waves @ Marseille I: Hypersonics, Shock Tube & Shock Tunnel Flow", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201111-190742416", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "F 49620-92-J-0110" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Brun-R", "name": { "family": "Brun", "given": "Raymond" } }, { "id": "Dumitrescu-L-Z", "name": { "family": "Dumitrescu", "given": "Lucien Z." } } ] }, "doi": "10.1007/978-3-642-78829-1_10", "pub_year": "1995", "author_list": "Sanderson, S. R. and Sturtevant, B." }, { "id": "https://authors.library.caltech.edu/records/eycmr-dn393", "eprint_id": 52231, "eprint_status": "archive", "datestamp": "2023-08-20 05:07:03", "lastmod": "2023-10-18 19:41:16", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Roshko-A", "name": { "family": "Roshko", "given": "A." } } ] }, "title": "Flow visualization as a basic research tool", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1995 Begell House. \n\nI wish to acknowledge the contributions of the many students and colleagues,\nsome of them mentioned here, with whom I have been associated and everyone of whom added original ideas to the uses of flow-visualization. In particular, I wish to mention Hans W. Liepmann, who turned me on to this fascinating world when I first obtained a schlieren photo of a transonic flow.", "abstract": "In this presentation, we briefly describe some of the research projects in\nGALCIT in which flow visualization played a central role.", "date": "1995", "date_type": "published", "publisher": "Begell House", "place_of_pub": "New York, NY", "pagerange": "983-994", "id_number": "CaltechAUTHORS:20141201-131151732", "isbn": "1567000363", "book_title": "Flow visualization VII : proceedings of the Seventh International Symposium on Flow Visualization, September 11-14, 1995, Seattle, Washington", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141201-131151732", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Crowder-J-P", "name": { "family": "Crowder", "given": "J. P." } } ] }, "pub_year": "1995", "author_list": "Roshko, A." }, { "id": "https://authors.library.caltech.edu/records/m47kx-h8y53", "eprint_id": 107721, "eprint_status": "archive", "datestamp": "2023-08-22 10:14:59", "lastmod": "2024-01-15 21:21:09", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Pullin-D-I", "name": { "family": "Pullin", "given": "D. I." } }, { "id": "Saffman-P-G", "name": { "family": "Saffman", "given": "P. G." } } ] }, "title": "Vortex models of the fine scales of turbulence", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Probability Density Function; Isotropic Turbulence; Vorticity Field; Inertial Range; Vorticity Distribution", "note": "\u00a9 Springer-Verlag Berlin Heidelberg 1995. \n\nDIP was partially supported by NSF Grant CTS-9311811 and PGS was partially supported by the Department of Energy under Grant No. DE-FG03-89ER25073.", "abstract": "We survey the current status, prospects and problems of vortex models of the fine scales of turbulence. We begin with the attempt by Synge and Lin in the 1940's to calculate the longitudinal velocity correlation for isotropic tubulence using an ensemble of Hill's spherical vortices. A discussion of models based on the Burgers vortex is followed by a detailed description of the use of an ensemble of randomly oriented stretched spiral-vortex solutions of the Navier-Stokes equations to predict/postdict several small-scale properties of stationary homogeneous tubulence at large wavenumber. These include the spectra of various quantities and the one-point velocity gradient statistics.", "date": "1995", "date_type": "published", "publisher": "Springer", "place_of_pub": "Berlin", "pagerange": "61-74", "id_number": "CaltechAUTHORS:20210125-155052849", "isbn": "978-3-540-60486-0", "book_title": "Small-Scale Structures in Three-Dimensional Hydrodynamic and Magnetohydrodynamic Turbulence", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210125-155052849", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "CTS-9311811" }, { "agency": "Department of Energy (DOE)", "grant_number": "DE-FG03-89ER25073" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Meneguzzi-Maurice", "name": { "family": "Meneguzzi", "given": "Maurice" } }, { "id": "Pouquet-Annick", "name": { "family": "Pouquet", "given": "Annick" } }, { "id": "Sulem-Pierre-Louis", "name": { "family": "Sulem", "given": "Pierre-Louis" } } ] }, "doi": "10.1007/BFb0102400", "pub_year": "1995", "author_list": "Pullin, D. I. and Saffman, P. G." }, { "id": "https://authors.library.caltech.edu/records/dvbta-wh554", "eprint_id": 106261, "eprint_status": "archive", "datestamp": "2023-08-20 05:12:10", "lastmod": "2024-01-15 18:14:09", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "H. G." }, "orcid": "0000-0002-4903-8419" }, { "id": "Germain-P", "name": { "family": "Germain", "given": "P." } } ] }, "title": "An Exploratory Study of Transition on a Slender Cone in Hypervelocity Flow", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Hypervelocity, transition, shock tunnel, sharp cone", "note": "\u00a9 Springer-Verlag Berlin Heidelberg 1995. \n\nThis work was supported by AFOSR URI grant F49620-93-1-0338 (Dr. J. Tishkoff) and AFOSR grant F49610-92-J-0110 (Dr. L. Sakell).", "abstract": "Results are presented from an experimental exploratory study of laminar, transitional and turbulent boundary layers on a slender, sharp cone at zero incidence in hypervelocity flow. The study was conducted in the hypervelocity shock tunnel T5, whose high operating pressure permits achieving the necessary high Reynolds numbers at high total enthalpy. Surface heat transfer rate and resonantly enhanced flow visualization were used to determine transition location and flow structure. Results indicate that the transition mechanism at the conditions tested is via the Tollmien-Schlichting instability. No detailed information about the noise spectrum in the facility is available. A strong, gas-dependent increase of the transition Reynolds number evaluated at the reference temperature on specific total enthalpy was observed. This effect increases monotonically with the dissociation energy of the gas.", "date": "1995", "date_type": "published", "publisher": "Springer Berlin Heidelberg", "place_of_pub": "Berlin, Heidelberg", "pagerange": "155-162", "id_number": "CaltechAUTHORS:20201023-102059086", "isbn": "9783642797675", "book_title": "Laminar-Turbulent Transition", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201023-102059086", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "F49620-93-1-0338" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "F49610-92-J-0110" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Kobayashi-Ryoji", "name": { "family": "Kobayashi", "given": "Ryoji" } } ] }, "doi": "10.1007/978-3-642-79765-1_18", "pub_year": "1995", "author_list": "Hornung, H. G. and Germain, P." }, { "id": "https://authors.library.caltech.edu/records/kz81w-3mq21", "eprint_id": 107720, "eprint_status": "archive", "datestamp": "2023-08-22 10:14:52", "lastmod": "2024-01-15 21:21:07", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Mader-H-M", "name": { "family": "Mader", "given": "H. M." } }, { "id": "Zhang-Y", "name": { "family": "Zhang", "given": "Y." } }, { "id": "Phillips-J-C", "name": { "family": "Phillips", "given": "J. C." } }, { "id": "Sparks-R-S-J", "name": { "family": "Sparks", "given": "R. S. J." } }, { "id": "Sturtevant-B", "name": { "family": "Sturtevant", "given": "B." } }, { "id": "Stolper-E-M", "name": { "family": "Stolper", "given": "E." }, "orcid": "0000-0001-8008-8804" } ] }, "title": "Observations of Explosive Exsolution in Liquids", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Bubble Growth; Explosive Eruption; Spherical Bubble; Volcanic Conduit; Bubble Growth Rate", "note": "\u00a9 Springer Science+Business Media Dordrecht 1995.", "abstract": "Explosive two-phase (gas-liquid) flows generated by rapid degassing of supersaturated liquids have been investigated experimentally to simulate conditions in violent volcanic eruptions. Two configurations were examined: i) Decompression of CO\u2082-saturated (P_(CO\u2082) \u22640.7 MPa) water causes explosive bubble growth and foaming. The large volume increase accelerates the two-phase mixture upward to velocities as large as 14 m/s at nearly constant accelerations up to more than 200 g. Constant acceleration implies that the bubble growth rate is proportional to t^(2/3), i.e., bubble size increases with time more rapidly than the t^(1/2) law expected for simple diffusive growth of spherical bubbles in an infinite medium, ii) Rapid mixing of concentrated K\u2082CO\u2083 and HCl solutions generates CO\u2082 supersaturations up to a few MPa. In this case, reaction and degassing generate an increasingly accelerating flow until the reactants become depleted at peak accelerations of about 100 g and velocities up to 45 m/s. In both experiments the rapid expansion causes the foam to fragment into a heterogeneous spray. The experimental flows are comparable to explosive volcanic flows in terms of decompression ratio, velocities, accelerations and in the large range of scales present. In addition, because the flow is confined to a conduit, the large accelerations cause strong extensional strain and longitudinal deformation of the foam. We speculate that widespread tube pumice in Plinian pyroclastic deposits and ignimbrites could preserve evidence of analogous flow conditions.", "date": "1995", "date_type": "published", "publisher": "Springer", "place_of_pub": "Dordrecht", "pagerange": "335-341", "id_number": "CaltechAUTHORS:20210125-154413929", "isbn": "978-94-010-4030-3", "book_title": "IUTAM Symposium on Waves in Liquid/Gas and Liquid/Vapour Two-Phase Systems", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210125-154413929", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "contributors": { "items": [ { "id": "Morioka-Shigeki", "name": { "family": "Morioka", "given": "Shigeki" } }, { "id": "Van-Wijngaarden-Leen", "name": { "family": "Van Wijngaarden", "given": "Leen" } } ] }, "doi": "10.1007/978-94-011-0057-1_28", "pub_year": "1995", "author_list": "Mader, H. M.; Zhang, Y.; et el." }, { "id": "https://authors.library.caltech.edu/records/23b55-thr17", "eprint_id": 41294, "eprint_status": "archive", "datestamp": "2023-08-20 05:03:09", "lastmod": "2023-10-24 23:37:10", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Westerweel-J", "name": { "family": "Westerweel", "given": "J." } }, { "id": "Dabiri-D", "name": { "family": "Dabiri", "given": "D." } }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "M." } } ] }, "title": "Noise reduction by discrete image shifting in DPIV", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1995 Begell House.\nThe research of dr.ir. J. Westerweel has been made possible by a fellowship of the Royal Netherlands\nAcademy of Arts and Sciences. The visit of dr.ir. J. Westerweel to the C.Q.V. was supported by\nURI (N00014-92-J-1618) from the Office of Naval Research.", "abstract": "Image shifting by removing the integer-pixel displacement in cross-correlation analysts of\nsingle-exposure digital image pairs optimizes the accuracy for estimating the location of the\ndisplacement-correlation peak in digital particle image velocimetry (PJV). The effect is predicted\nby an analytical model for the statistical properties of estimators for the displacement. The predicted\nnoise reduction is observed in the analysis of synthetic PIV images of isotropic turbulence and in actual measurements of grid-generated turbulence.", "date": "1995", "date_type": "published", "publisher": "Begell House", "place_of_pub": "New York", "pagerange": "688-694", "id_number": "CaltechAUTHORS:20130912-131326617", "isbn": "9781567000368", "book_title": "Flow visualization VII", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130912-131326617", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Royal Netherlands Academy of Arts and Sciences" }, { "agency": "Office of Naval Research (ONR) URI", "grant_number": "N00014-92-J-1618" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Crowder-J-P", "name": { "family": "Crowder", "given": "J. P." } } ] }, "pub_year": "1995", "author_list": "Westerweel, J.; Dabiri, D.; et el." }, { "id": "https://authors.library.caltech.edu/records/k78eh-6hz86", "eprint_id": 20928, "eprint_status": "archive", "datestamp": "2023-08-20 05:01:46", "lastmod": "2024-01-13 00:06:42", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Culick-F-E-C", "name": { "family": "Culick", "given": "Fred E. C." } }, { "id": "Yang-V", "name": { "family": "Yang", "given": "Vigor" } } ] }, "title": "Overview of Combustion Instabilities in Liquid-Propellant Rocket Engines", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 1995 by F. E. C. Culick and V. Yang. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission. The authors are indebted to Josef M. Wicker for many helpful discussions of feedback loop of combustion instability.\n\nPublished - 380_Culick_FEC_1995.pdf
", "abstract": "N/A", "date": "1995", "date_type": "published", "publisher": "American Institute of Aeonautics and Astrophysics", "place_of_pub": "Washington, DC", "pagerange": "3-37", "id_number": "CaltechAUTHORS:20101122-074028101", "isbn": "978-1-60086-418-6", "book_title": "Liquid Rocket Engine Combustion Instability", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20101122-074028101", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "name": "Guggenheim Jet Propulsion Center" } ] }, "local_group": { "items": [ { "id": "Guggenheim-Jet-Propulsion-Center" }, { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Yang-V", "name": { "family": "Yang", "given": "V." } }, { "id": "Anderson-W", "name": { "family": "Anderson", "given": "W." } } ] }, "primary_object": { "basename": "380_Culick_FEC_1995.pdf", "url": "https://authors.library.caltech.edu/records/k78eh-6hz86/files/380_Culick_FEC_1995.pdf" }, "pub_year": "1995", "author_list": "Culick, Fred E. C. and Yang, Vigor" }, { "id": "https://authors.library.caltech.edu/records/t33zg-34y23", "eprint_id": 79694, "eprint_status": "archive", "datestamp": "2023-08-22 10:12:45", "lastmod": "2023-10-26 17:02:25", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Germain-P", "name": { "family": "Germain", "given": "P." } }, { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "H." }, "orcid": "0000-0002-4903-8419" } ] }, "title": "The Boundary Layer on a Sharp Cone in High-Enthalpy Flow", "ispublished": "unpub", "full_text_status": "public", "keywords": "Hypervelocity; Boundary layer transition; Experiment", "note": "\u00a9 1995 Springer-Verlag Berlin Heidelberg.", "abstract": "The boundary layer on a 5 deg. half-angle cone is studied by measurement of the heat flux distribution and by qualitative flow visualisation. In the laminar layer, heat flux levels are higher in air than in nitrogen because of a larger heat release from oxygen recombination at the wall. By varying the specific reservoir enthalpy in air and N_2, and from measurements in CO_2, it is found that real-gas effects stabilize the boundary layer.", "date": "1995", "date_type": "published", "publisher": "Springer", "place_of_pub": "Berlin", "pagerange": "63-68", "id_number": "CaltechAUTHORS:20170801-133028549", "isbn": "978-3-642-78831-4", "book_title": "Shock Waves @ Marseille I - Hypersonics, Shock Tube & Shock Tunnel Flow", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170801-133028549", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Brun-R", "name": { "family": "Brun", "given": "Raymond" } }, { "id": "Dumitrescu-L-Z", "name": { "family": "Dumitrescu", "given": "Lucien Z." } } ] }, "doi": "10.1007/978-3-642-78829-1_9", "pub_year": "1995", "author_list": "Germain, P. and Hornung, H." }, { "id": "https://authors.library.caltech.edu/records/ga3nt-qqb48", "eprint_id": 41857, "eprint_status": "archive", "datestamp": "2023-08-20 05:03:58", "lastmod": "2023-10-25 14:51:05", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Shank-J", "name": { "family": "Shank", "given": "J." } }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "M." } } ] }, "title": "Super-Resolution Particle Tracking Velocimetry", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1995 Begell House.\nThis work was sponsored by the Defense Advanced Research Project Agency-ACMP\nthrough the URI program under contract number DARPA/ACMP N00014-86-K-0758.", "abstract": "Digital particle image velocimetry (DPIV) is a quantitative flow visualization technique\nthat uses digitally recorded video images to measure the velocity field of fluid flows\n(Willert and Gharib, 1991). In a typical DPIV application, the flow field is seeded with\nsmall particles, a planar region of interest is illuminated with a laser sheet, and images are\nrecorded onto videodisk. Displacement data are recovered from the captured image by\nlocating the peak of the cross-correlation between small portions of the image. The\nspatial resolution of conventional DPN is thus limited to the order of the interrogation\nwindow's size, typically 32x32 pixels. In this paper, we report on the development of an\nimage analysis technique that uses a combination of cross-correlation, pattern recognition,\nand particle tracking to improve the spatial resolution of DPIV to the mean distance\nbetween particles. We refer to this a super-resolution particle tracking velocimetry.", "date": "1995", "date_type": "published", "publisher": "Begell House", "place_of_pub": "New York", "pagerange": "636-640", "id_number": "CaltechAUTHORS:20131010-090427424", "isbn": "9781567000368", "book_title": "Flow Visualization VII", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131010-090427424", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "DARPA/ACMP", "grant_number": "N00014-86-K-0758" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Crowder-J-P", "name": { "family": "Crowder", "given": "J. P." } } ] }, "pub_year": "1995", "author_list": "Shank, J. and Gharib, M." }, { "id": "https://authors.library.caltech.edu/records/dvfsy-6j779", "eprint_id": 41293, "eprint_status": "archive", "datestamp": "2023-08-20 05:03:02", "lastmod": "2023-10-24 23:37:06", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Dabiri-D", "name": { "family": "Dabiri", "given": "Dana" } }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "Morteza" } } ] }, "title": "Digital particle image thermometry and velocimetry", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1995 Begell House.\n\nThis work is sponsored by the Defense Advanced Research Project Agency - ACMP through\nthe URI program under contract number DARPA/ACMP N00014-86-k-0758.", "abstract": "The transport of heat by buoyancy driven convection is a problem of great importance. As\nsuch, there have been many experimental, numerical, and theoretical works done in this field.\nThese works can be classified into one of two areas: external flows, where, for example, the flow\nfrom heated rods and plates placed within a still fluid are studied, and internal flows, where, for\nexample, flows within rectangular or circular cavities are studied.", "date": "1995", "date_type": "published", "publisher": "Begell House", "place_of_pub": "New York", "pagerange": "558-563", "id_number": "CaltechAUTHORS:20130912-130354032", "isbn": "9781567000368", "book_title": "Flow visualization VII", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130912-130354032", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "DARPA/ACMP", "grant_number": "N00014-86-k-0758" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Crowder-J-P", "name": { "family": "Crowder", "given": "J. P." } } ] }, "pub_year": "1995", "author_list": "Dabiri, Dana and Gharib, Morteza" }, { "id": "https://authors.library.caltech.edu/records/wc07q-c4465", "eprint_id": 41855, "eprint_status": "archive", "datestamp": "2023-08-20 05:03:43", "lastmod": "2023-10-25 14:50:55", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Gharib-M", "name": { "family": "Gharib", "given": "Morteza" } }, { "id": "Rambod-E", "name": { "family": "Rambod", "given": "Edmond" } }, { "id": "Sahn-D-J", "name": { "family": "Sahn", "given": "David J." } } ] }, "title": "Quantitative flow visualization as a diagnostic tool for intracardiac fluid dynamics studies", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1995 Begell House.", "abstract": "The cardiovascular system is comprised of two main components: central (the heart) and\nperipheral (the blood vessels). The heart, as the center of this system, is responsible for supplying the\nblood to all body systems such as the brain, liver, muscle, kidney, skin, and blood vessels. Therefore,\nefficient functioning of the heart is imperative for the functionality of all other essential organs.", "date": "1995", "date_type": "published", "publisher": "Begell House", "place_of_pub": "New York", "pagerange": "14-25", "id_number": "CaltechAUTHORS:20131010-085340185", "isbn": "9781567000368", "book_title": "Flow Visualization VII", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131010-085340185", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Crowder-J-P", "name": { "family": "Crowder", "given": "J. P." } } ] }, "pub_year": "1995", "author_list": "Gharib, Morteza; Rambod, Edmond; et el." }, { "id": "https://authors.library.caltech.edu/records/hrtmb-wvc45", "eprint_id": 41300, "eprint_status": "archive", "datestamp": "2023-08-20 05:03:15", "lastmod": "2023-10-24 23:37:33", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Dooley-B-S", "name": { "family": "Dooley", "given": "Bradley S." } }, { "id": "Warncke-A-E", "name": { "family": "Warncke", "given": "Amy E." } }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "Morteza" } }, { "id": "Tryggvason-G", "name": { "family": "Tryggvason", "given": "Gr\u00e9tar" } } ] }, "title": "Vortex ring generation due to the coalescence of a water drop at a free surface", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1995 Begell House.\nThis work received partial support from the Office of Naval Research, ONR-URI\nN00014-92-J-1610, with additional support from the National Science Foundation. Special\nthanks are due to Mr. S. Haase for help with the construction of the experimental apparatus and\nto Dr. P. Atsavapranee for assistance with the photography.", "abstract": "The formation of a vortex ring in a pool by contact with a fluid drop is a familiar\nphenomenon easily generated by milk drops in a glass of water. First observed over a century\nago by Thomson and Newall (1885), however, much about the process is not well understood.\nFor simplicity, much of the work done has been restricted to the case of the the drop and pool\nhaving identical composition. Chapman and Critchlow (1967) characterize the rings formed by\nfalling drops in terms of the drop shape at the time of impact and propose a quantitative model of\nthe vortex ring's generation process. Peck and Sigurdson (1994) analyze the structure of rings as\nthey penetrate into the pool after a fall. Hsiao, et al. (1988) experimentally determine a critical\nWeber number for the falling drop (We \u2248 8) above which a jet, rather than a vortex ring, is\nformed in the pool. It should be noted that the Peck and Sigurdson drops had a We range of 22-25, which seems to contradict the earlier work of Hsiao, et al. To further simplify matters, the\ndegenerate case (We = 0) in which contact between the drop and pool occurs with zero velocity\nmay be examined. Shankar and Kumar (1995) observe the evolutionary behavior of rings so\ngenerated, and characterize the zero velocity case as a function of two dimensionless parameters\nonly. In this work we visualize the formation of the ring rather than its evolution, and\nquantitatively examine a simplified scaling law based on the analyses of Hsiao, et. al and\nShankar and Kumar. This scaling law, when valid, allows the flow conditions to be expressed in\na single dimensionless parameter. Validity, however, requires that surface tension forces\ndominate gravitational and viscous ones in the vortex ring formation process.", "date": "1995", "date_type": "published", "publisher": "Begell House", "place_of_pub": "New York", "pagerange": "392-397", "id_number": "CaltechAUTHORS:20130912-145816021", "isbn": "9781567000368", "book_title": "Flow visualization VII", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130912-145816021", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR-URI) Grant", "grant_number": "N00014-92-J-1610" }, { "agency": "NSF" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Crowder-J-P", "name": { "family": "Crowder", "given": "J. P." } } ] }, "pub_year": "1995", "author_list": "Dooley, Bradley S.; Warncke, Amy E.; et el." }, { "id": "https://authors.library.caltech.edu/records/y2js2-rpr16", "eprint_id": 41858, "eprint_status": "archive", "datestamp": "2023-08-20 05:04:05", "lastmod": "2023-10-25 14:51:07", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Maheo-P-M", "name": { "family": "Maheo", "given": "P. M." } }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "M." } }, { "id": "Henderson-R-D", "name": { "family": "Henderson", "given": "R. D." } } ] }, "title": "Start-up flow past a circular cylinder: A comparison between DPIV and DNS", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1995 Begell House.\nWe are pleased to acknowledge the support of this ongoing research by the Office of\nNaval Research through contract No. N00014-93-1144. R. D. H. acknowledges support from\nthe National Science Foundation under Grant No. CDA-9318145.", "abstract": "There have been a considerable number of theoretical, experimental and computational\nstudies on vortex shedding. Experimental investigations of unsteady flow behind a starting\ncircular cylinder date back to the Prandtl era [1]. The most extensive experiments to date\nfor an impulsively started cylinder are those presented by Bouard and Coutanceau [2]. At\nthe same time, considerable effort has been directed toward finding both analytical and accurate\nfinite-difference solutions. This previous work provided extensive information about\nthe main flow characteristics but was limited in several respects: all the known analytical\nsolutions are only valid for short times; finite-difference methods often suffer from numerical\nstability and dissipation problems; and experimental data is limited in both spatial and temporal\nresolution. The recent development of techniques for measuring instantaneous fields of\nvectors with high spatial and temporal resolution, such as PIV [3] and its digital counterpart\nDPIV [4], was an important achievement for modern experimental fluid mechanics. Furthermore,\nspectral domain decomposition methods have been developed that provide better\naccuracy and take full advantage of parallel supercomputers for high-resolution calculations.\nIn this paper, complementary advanced experimental and numerical techniques are used to\nobtain information on secondary flow quantities such as the vorticity, quantities that are\ncrucial in understanding the dynamics of coherent structures.\n\n\nThe present study deals with the determination of the plane viscous flow around a circular\ncylinder that accelerates linearly from rest to a constant speed U_0 in a quiescent fluid. We\ndefine the Reynolds number as Re \u2261 U_0d/\u03bd, where d is the cylinder diameter and \u03bd is the\nkinematic viscosity of the fluid. In the results presented here, Re \u2248 1000 and the acceleration\ntime is t* \u2261 tU_0/d = 1.575. The objective of this coordinated experimental-computational\nstudy is to compare experimental techniques (DPIV) and numerical simulations (DNS) for\nthe start-up flow past a circular cylinder. We chose this problem because its initial features\nare two-dimensional and it exhibits behavior characteristic of bluff body wake dynamics. The\npurpose of this ongoing research is to try to shed some light on the fundamental mechanisms\ngoverning the vortex formation process by monitoring the evolution of the flow field.", "date": "1995", "date_type": "published", "publisher": "Begell House", "place_of_pub": "New York", "pagerange": "708-714", "id_number": "CaltechAUTHORS:20131010-090910376", "isbn": "9781567000368", "book_title": "Flow Visualization VII", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131010-090910376", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-93-1144" }, { "agency": "NSF", "grant_number": "CDA-9318145" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Crowder-J-P", "name": { "family": "Crowder", "given": "J. P." } } ] }, "pub_year": "1995", "author_list": "Maheo, P. M.; Gharib, M.; et el." }, { "id": "https://authors.library.caltech.edu/records/xgakm-wxb94", "eprint_id": 104494, "eprint_status": "archive", "datestamp": "2023-08-20 05:11:53", "lastmod": "2023-10-20 20:31:32", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Akbar-R", "name": { "family": "Akbar", "given": "R." } }, { "id": "Schendeman-D-W", "name": { "family": "Schwendeman", "given": "D. W." } }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "J. E." }, "orcid": "0000-0003-3181-9310" }, { "id": "Williams-R-L", "name": { "family": "Williams", "given": "R. L." } }, { "id": "Thomas-G-O", "name": { "family": "Thomas", "given": "G. O." } } ] }, "title": "Wave Shaping Channels for Gaseous Detonations", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Detonation, Shock dynamics, Convergence", "note": "\u00a9 Springer-Verlag Berlin Heidelberg 1995.", "abstract": "The problem of detonation wave shaping by converging channels was investigated computationally and experimentally. Whitham's method of shock dynamics, extended to gaseous detonations, was used to design a converging channel to produce an overdriven, planar detonation. The channel was designed for a detonation in a stoichiometric oxygen-acetylene mixture with an inlet Mach number of 7.3 and an exit Mach number of 7.8, corresponding to an overdrive ratio of 1.07. It was tested experimentally at initial pressures ranging from 15 to 60 Torr. Soot foil records indicate smooth wavefronts with a gradual decrease in detonation cell-width along the channel. The overdrive ratios, estimated from changes in cell size, ranged from 1.01 to 1.05.", "date": "1995", "date_type": "published", "publisher": "Springer", "place_of_pub": "Berlin", "pagerange": "465-470", "id_number": "CaltechAUTHORS:20200721-162844821", "isbn": "9783642795343", "book_title": "Shock Waves @ Marseille IV: Shock Structure and Kinematics, Blast Waves and Detonations", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200721-162844821", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Brun-R", "name": { "family": "Brun", "given": "Raymond" } }, { "id": "Dumitrescu-L-Z", "name": { "family": "Dumitrescu", "given": "Lucien Z." } } ] }, "doi": "10.1007/978-3-642-79532-9_77", "pub_year": "1995", "author_list": "Akbar, R.; Schwendeman, D. W.; et el." }, { "id": "https://authors.library.caltech.edu/records/xsn56-pnk93", "eprint_id": 41856, "eprint_status": "archive", "datestamp": "2023-08-20 05:03:50", "lastmod": "2023-10-25 14:51:00", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Dabiri-D", "name": { "family": "Dabiri", "given": "Dana" } }, { "id": "Zhang-X", "name": { "family": "Zhang", "given": "Xin" } }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "Morteza" } } ] }, "title": "A real-time free surface slope mapping technique", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1995 Begell House.\n\nThis work is carried out under a URI grant (N00014-92-J-1618) from the Office of Naval\nResearch.", "abstract": "Recently, there has been an increased interest in the interaction of vortices and turbulence with\nfree surfaces. A central issue in understanding the free surface turbulence is to relate the surface\nelevation to the near surface flow field. In that respect, the Jack of a global surface mapping\ntechnique which could reveal the temporal evolution of the surface elevation has prevented the\nprogress of viable research. Thus, it is the purpose of this work to present a new technique\nintegrating optics, colorimetry, digital image processing, to measure the 3-D surface elevation for a\ntime-evolving flow.\n\nIt is highly undesirable to use a probe which extends through the water surface to study surface\nstructures due to the fact that the probe interacts with the free surface. It is therefore desirable to\nuse optical methods since these techniques do not interfere with the free surface. As suggested by\nCox, it is convenient to measure the water-surface slope instead of the free surface elevation, since\nthe higher frequency waves have lower amplitudes while they maintain higher slopes. Therefore,\nCox (1958) measured the surface slope by the refraction of light through a free surface. A light\nsource of spatially linearly-varying intensity was placed at the bottom of a water tunnel, and a\ntelescope imaged one point on the water surface into a photocell. Therefore, the brightness of the\nlight seen by the photocell was proportioned to one component of the slope of the free surface.\nThis technique is referred to as the \"refraction mode\" since the observed light rays are refracted\nthrough the surface. Likewise, one can perform the experiment by illuminating the surface of the\nwater from air and observing the reflections. This technique is referred to as the \"reflective mode\"\nsince the observed light rays are reflected from the surface. Using a photo diode array and a laser\nas a single point light source, Long and Huang (1976) were able to measure both components of\nthe surface slope at one point. Further work done by Keller and Gotwols (1983), Jahne and Waas\n(1989), and Jahne and Riemer (1990), progressed the technique to allow for two slope component\nmeasurements, one slope at a time. Zhang and Cox (1992) extended this work by allowing the\nmeasurement of two slope components simultaneously, throughout a two-dimensional spatial\ndomain. Since the technique is photographically-based, it allowed data acquisition at only one\npoint in time. In this paper, we report on the development of a real-time version of this technique\nthat facilitates studies of time evolving flows.", "date": "1995", "date_type": "published", "publisher": "Begell House", "place_of_pub": "New York", "pagerange": "290-294", "id_number": "CaltechAUTHORS:20131010-085806642", "isbn": "9781567000368", "book_title": "Flow Visualization VII", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131010-085806642", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR) URI", "grant_number": "N00014-92-J-1618" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Crowder-J-P", "name": { "family": "Crowder", "given": "J. P." } } ] }, "pub_year": "1995", "author_list": "Dabiri, Dana; Zhang, Xin; et el." }, { "id": "https://authors.library.caltech.edu/records/7sxy7-w9420", "eprint_id": 41325, "eprint_status": "archive", "datestamp": "2023-08-20 05:03:20", "lastmod": "2024-01-13 06:04:05", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Raffel-M", "name": { "family": "Raffel", "given": "M." } }, { "id": "Westerweel-J", "name": { "family": "Westerweel", "given": "J." } }, { "id": "Willert-C", "name": { "family": "Willert", "given": "C." }, "orcid": "0000-0002-1668-0181" }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "M." } }, { "id": "Kompenhans-J", "name": { "family": "Kompenhans", "given": "J." } } ] }, "title": "Analytical and experimental investigations of dual-plane PIV", "ispublished": "unpub", "full_text_status": "public", "keywords": "particle image velocimetry, dual-plane correlation, scanning light sheet, three-dimensional flow measurements", "note": "\u00a9 1995 SPIE.\nThe authors would like to thank DLR for supporting Markus Raffel's visit to Caltech (CQV), and the Office of Naval\nResearch through the URI grant ONR-URI-N00014-92-J-1610. The research of Dr.ir. J. Westerweel has been made\npossible by a fellowship of the Royal Netherlands Academy of Arts and Sciences.\n\nPublished - Gharib_1995p75.pdf
", "abstract": "In its 'classical' form particle image velocimetry (PIV) extracts two components of the flow velocity vector by measuring the displacement of tracer particles within a double-pulsed laser light sheet. The method described in this paper is based on the additional recording of a third exposure of the tracer particles in a parallel light sheet, which is slightly displaced with respect to the first one. The particle images resulting from these three exposures are stored on separate frames. The locations of the correlation peaks, as obtained by cross-correlation methods, are used to determine the projections of the velocity vectors onto the plane between both light sheets. In the manner described below, the amplitudes of these peaks are used to obtain information about the velocity component perpendicular to the light sheet planes. The mathematical background of this method is described in the paper. Numerical simulations show the influence of the main parameters (e.g. light sheet thickness, light sheet displacement and out-of-plane component) on the resolution and reliability of the new method. Two different recording procedures and their results will be shown to demonstrate the ease of operation when applying this technique to liquid flows.", "date": "1995", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers", "place_of_pub": "Bellingham, WA", "pagerange": "75-86", "id_number": "CaltechAUTHORS:20130913-132604801", "isbn": "9780819419057", "book_title": "Optical techniques in fluid, thermal, and combustion flow", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130913-132604801", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR-URI)", "grant_number": "N00014-92-J-1610" }, { "agency": "Royal Netherlands Academy of Arts and Sciences" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.1117/12.221511", "primary_object": { "basename": "Gharib_1995p75.pdf", "url": "https://authors.library.caltech.edu/records/7sxy7-w9420/files/Gharib_1995p75.pdf" }, "pub_year": "1995", "author_list": "Raffel, M.; Westerweel, J.; et el." }, { "id": "https://authors.library.caltech.edu/records/p8w6j-5rf39", "eprint_id": 86797, "eprint_status": "archive", "datestamp": "2023-08-20 04:21:29", "lastmod": "2024-01-14 20:14:23", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Goano-M", "name": { "family": "Goano", "given": "M." } }, { "id": "Torasso-E", "name": { "family": "Torasso", "given": "E." } }, { "id": "Montrosset-I", "name": { "family": "Montrosset", "given": "I." } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "S." }, "orcid": "0000-0001-9373-3278" }, { "id": "Re-M", "name": { "family": "Re", "given": "M." } }, { "id": "Reichenbach-D", "name": { "family": "Reichenbach", "given": "D." } } ] }, "title": "Design of high-power ridge waveguide 980-nm pump lasers", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 1994 Society of Photo-Optical Instrumentation Engineers (SPIE). \n\nThe autors acknowledge the contribution of Mr. L. Cicchelli in the development of the latest version of the simulator. M.G., E.T. and I.M. acknowledge the partial support from Camera di Commercio di Torino under Research Grant \"All-Optical Communication Networks\".\n\nPublished - 52.pdf
", "abstract": "The design of ridge waveguide semiconductor pump lasers poses particular simulation problems, since an accurate modeling of the electric and thermal effects and of the optical guiding capabilities is needed. We developed a model whose self-consistent application allows the evaluation of, among others, the threshold current of the lasing mode and the gain margin of the higher order modes, the P-I characteristic, the power coupled in the fiber, and the far field pattern. Particular attention is paid to the experimental verification of the transverse single mode operation region, and its evolution at high injection levels. The appropriate conditions for operation in the 150 - 200 mW single mode output power range have been found.", "date": "1994-06-01", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "52-63", "id_number": "CaltechAUTHORS:20180605-132224863", "isbn": "0-8194-1443-3", "book_title": "Laser Diode Technology and Applications VI", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180605-132224863", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Camera di Commercio di Torino" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Chen-Pei-Chuang", "name": { "family": "Chen", "given": "Pei Chuang" } }, { "id": "Johnson-L-A", "name": { "family": "Johnson", "given": "Lawrence A." } }, { "id": "Temkin-H", "name": { "family": "Temkin", "given": "Henryk" } } ] }, "doi": "10.1117/12.176643", "primary_object": { "basename": "52.pdf", "url": "https://authors.library.caltech.edu/records/p8w6j-5rf39/files/52.pdf" }, "pub_year": "1994", "author_list": "Goano, M.; Torasso, E.; et el." }, { "id": "https://authors.library.caltech.edu/records/mt0r0-7a411", "eprint_id": 87139, "eprint_status": "archive", "datestamp": "2023-08-20 04:14:38", "lastmod": "2024-01-14 20:14:50", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "S." }, "orcid": "0000-0001-9373-3278" }, { "id": "Re-M-G", "name": { "family": "Re", "given": "M. G." } }, { "id": "Beoni-C", "name": { "family": "Beoni", "given": "C." } }, { "id": "Reichenbach-D", "name": { "family": "Reichenbach", "given": "D." } }, { "id": "Vidimari-F", "name": { "family": "Vidimari", "given": "F." } } ] }, "title": "Design of Al-free and Al-based InGaAs/GaAs strained quantum well 980-nm pump lasers including thermal behavior effects on E/O characteristics", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 1994 Society of Photo-Optical Instrumentation Engineers (SPIE). \n\nThe authors are indebt to Prof. I.Montrosset, Dr. M.Goano and Mr. E.Torasso from Politecnico di Torino for their valuable suggestions, and all the Alcatel-Telettra Laser Laboratory staff for their help during the work.\n\nPublished - 20.pdf
", "abstract": "A 2D thermal simulator and a model to evaluate high power lasers characteristics have been developed. With these models it was possible to optimize cavity length of InGaAs/GaAs (Multiple) Quantum Well 980 nm lasers realized both with Al-based and Al-free confining layers. A comprehensive experimental investigation of the influence of cavity length and temperature on the laser emission wavelength has been performed. This allows a fine trimming of the devices to match the Erbium doped fiber absorption bandwidth.", "date": "1994-05-02", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "20-28", "id_number": "CaltechAUTHORS:20180614-160352068", "isbn": "081941445X", "book_title": "Design, Simulation, and Fabrication of Optoelectronic Devices and Circuits", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180614-160352068", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Armenise-M-N", "name": { "family": "Armenise", "given": "Mario Nicola" } } ] }, "doi": "10.1117/12.175004", "primary_object": { "basename": "20.pdf", "url": "https://authors.library.caltech.edu/records/mt0r0-7a411/files/20.pdf" }, "pub_year": "1994", "author_list": "Pellegrino, S.; Re, M. G.; et el." }, { "id": "https://authors.library.caltech.edu/records/tw4wd-f1w64", "eprint_id": 86795, "eprint_status": "archive", "datestamp": "2023-08-20 04:14:33", "lastmod": "2024-01-14 20:14:18", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "S." }, "orcid": "0000-0001-9373-3278" }, { "id": "Pignataro-C", "name": { "family": "Pignataro", "given": "C." } }, { "id": "Caldironi-M", "name": { "family": "Caldironi", "given": "M." } }, { "id": "Dellagiovanna-M", "name": { "family": "Dellagiovanna", "given": "M." } }, { "id": "Vidimari-F", "name": { "family": "Vidimari", "given": "F." } }, { "id": "Carnera-A", "name": { "family": "Carnera", "given": "A." } }, { "id": "Gasparotto-A", "name": { "family": "Gasparotto", "given": "A." } } ] }, "title": "Disordering of InGaAs/GaAs strained quantum well structures induced by rare gas ion implantation", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 1994 Society of Photo-Optical Instrumentation Engineers (SPIE). \n\nWe are deeply indebt to Dr. C. Frigeri, MASPEC Parma, for TEN measurements and to Dr. A. DiPaola for continuous help during the work.\n\nPublished - 38.pdf
", "abstract": "In this work we have investigated the effect of various implantation schemes on In(0.2)GaAs/GaAs/AlGaAs Single Quantum Well, where the implanted species are Argon and Helium, with doses in the range 1E12 to 1E14 at cm^2, at energy spanning 270 - 400 KeV and 30 to 50 KeV for Ar and He, respectively. Repetitive annealing processes were carried out between 735 and 870 degree(s)C and the interdiffusion was deduced by photoluminescence measurements. A maximum of 20 nm shift from He ion implanted Quantum Well with an high degree of reconstruction has been recorded, thus allowing the application of this disordering scheme for the realization of optoelectronic devices.", "date": "1994-05-02", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "38-48", "id_number": "CaltechAUTHORS:20180605-131242041", "isbn": "081941445X", "book_title": "Design, Simulation, and Fabrication of Optoelectronic Devices and Circuits", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180605-131242041", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Armenise-M-N", "name": { "family": "Armenise", "given": "Mario Nicola" } } ] }, "doi": "10.1117/12.175013", "primary_object": { "basename": "38.pdf", "url": "https://authors.library.caltech.edu/records/tw4wd-f1w64/files/38.pdf" }, "pub_year": "1994", "author_list": "Pellegrino, S.; Pignataro, C.; et el." }, { "id": "https://authors.library.caltech.edu/records/z2ta5-p4t53", "eprint_id": 79696, "eprint_status": "archive", "datestamp": "2023-08-20 03:37:52", "lastmod": "2024-01-13 23:27:57", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "H." }, "orcid": "0000-0002-4903-8419" }, { "id": "Wen-C", "name": { "family": "Wen", "given": "C." } }, { "id": "Candler-G-V", "name": { "family": "Candler", "given": "G." } } ] }, "title": "Hypervelocity flow over spheres", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 1994 Springer-Verlag.", "abstract": "Some aspects of the principle of binary scaling of hypervelocity flows with chemical reactions are discussed and tested both numerically and experimentally. The experiments, obtained in a new free-piston shock tunnel, show the value and limitations of binary scaling in very good agreement with the numerical computations. The use of spherical models eliminates end-effect problems previously encountered with cylindrical models. Global quantities, such as the bow shock stand-off distance, follow binary scaling very well. The results include differential interferograms and surface heat transfer measurements of nitrogen, air and carbon dioxide flows.", "date": "1994", "date_type": "published", "publisher": "Springer", "place_of_pub": "Vienna", "pagerange": "163-170", "id_number": "CaltechAUTHORS:20170801-134738846", "isbn": "978-3-211-82495-5", "book_title": "Fluid- and Gasdynamics", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170801-134738846", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Schnerr-G-H", "name": { "family": "Schnerr", "given": "G. H." } }, { "id": "Bohning-R", "name": { "family": "Bohning", "given": "R." } }, { "id": "Frank-W", "name": { "family": "Frank", "given": "W." } }, { "id": "B\u00fchler-K", "name": { "family": "B\u00fchler", "given": "K." } } ] }, "doi": "10.1007/978-3-7091-9310-5_19", "pub_year": "1994", "author_list": "Hornung, H.; Wen, C.; et el." }, { "id": "https://authors.library.caltech.edu/records/k5dq8-dce33", "eprint_id": 79614, "eprint_status": "archive", "datestamp": "2023-08-20 02:10:16", "lastmod": "2023-10-26 16:58:59", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Roshko-A", "name": { "family": "Roshko", "given": "A." } } ] }, "title": "Instability and Turbulence in Shear Flows", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 1993 IUTAM. Published by Elsevier B.V.", "abstract": "Increasing attention is being paid to the large scale structure of turbulence and to the so-called \"coherent\" vortical structures which have been disclosed and studied for a number of turbulent shear flows in laboratory experiments and in numerical simulations. The coherent structures develop from the instability waves which create the flow; they portray the genesis of the turbulence in the primary instability of the global vorticity distribution. This is not in the sense of classical laminar instability, whichinitiates transition to turbulence, but as thedriving instability in the fully developed turbulence. That instability provides the link to the amplitude of the turbulent motion, which in classical turbulent modelling must be calibrated empirically as a fundamental step or steps in the closure of the Reynolds averaged equations of motion. It also rationalizes the dependence on various parameters, such as compressibility, clarifies response to external disturbances, and suggests the possibility of \"turbulence control\". The global instability is being incorporated into new models of turbulent shear flow development and the coherent structures form the basis for new, Lagrangian models of chemical mixing and reaction in these flows.", "date": "1993", "date_type": "published", "publisher": "Elsevier", "place_of_pub": "Amsterdam", "pagerange": "1-24", "id_number": "CaltechAUTHORS:20170731-142554277", "isbn": "978-0-444-88889-1", "book_title": "Theoretical and Applied Mechanics 1992", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170731-142554277", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Bodner-S-R", "name": { "family": "Bodner", "given": "S. R." } }, { "id": "Singer-J", "name": { "family": "Singer", "given": "J." } }, { "id": "Solan-A", "name": { "family": "Solan", "given": "A." } }, { "id": "Hashin-Z", "name": { "family": "Hashin", "given": "Z." } } ] }, "doi": "10.1016/B978-0-444-88889-1.50008-X", "pub_year": "1993", "author_list": "Roshko, A." }, { "id": "https://authors.library.caltech.edu/records/8ej75-5jx95", "eprint_id": 21851, "eprint_status": "archive", "datestamp": "2023-08-20 01:11:02", "lastmod": "2024-01-13 00:08:58", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Culick-F-E-C", "name": { "family": "Culick", "given": "F. E. C." } }, { "id": "Paparizos-Leonidas-G", "name": { "family": "Paparizos", "given": "L." } }, { "id": "Sterling-J", "name": { "family": "Sterling", "given": "J." } }, { "id": "Burnley-V-S", "name": { "family": "Burnley", "given": "V." } } ] }, "title": "Combustion noise and combustion instabilities in propulsion systems", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 1992, AGARD. This work has been supported partly by the\nCalifornia Institute of Technology; by the Office of\nNaval Research; by the Air Force Office of Scientific\nResearch; and by the National Aeronautics and\nSpace Administration.\n\nReprint - 331_Culick_FEC.pdf
", "abstract": "This paper is concerned with some aspects of non-linear behavior of unsteady motions in combustion chambers. The emphasis is on conditions under which organized oscillations having discrete frequencies may exist in the presence of random motions. In order to treat the two types of motions together, and particularly to investigate coupling between noise and combustion instabilities, the unsteady field is represented as a synthesis of acoustic modes having time-varying amplitudes. Each of the amplitudes are written as the sum of two parts, one associated with the random field and the remainder representing the organized oscillations. After spatial averaging, the general problem is reduced to solution of a set of second-order ordinary differential equations whose structure depends on the sorts of nonlinear processes accounted for. This formulation accommodates any physical process; in particular, terms are included to represent noise sources, although only limited modeling is discussed. Our results suggest that random sources of noise have only small effects on combustion instabilities and seem not to be a cause of unstable motions. However, the coupling between the two sorts of unsteady motions may be important as an essential process in a proposed scheme for noise control. It is now a familiar observation that many nonlinear deterministic systems are capable of exhibiting apparently random motions called 'chaos.' This is a particularly interesting possibility for systems which also executed non-deterministic random motions. In combustion chambers, a nonlinear deterministic system (acoustical motions) exists in the presence of noise produced by flow separation, turbulent motions, and energy released by combustion processes. The last part of the paper is directed to the matter of discovering whether or not chaotic motions exist in combustion systems. Analysis has not progressed sufficiently far to answer the question. We report here recent results of processing data taken in one combustor to determine the dimensions of any attractors in the motions. No evidence has been found for chaos in the strict sense, but the method seems to be an important means of investigating the nonlinear behavior of combustion systems.", "date": "1992-04", "date_type": "published", "publisher": "Advisory Group for Aerospace Research and Development, North Atlantic Treaty Organization", "place_of_pub": "Neuilly sur Seine, France", "pagerange": "18-1", "id_number": "CaltechAUTHORS:20110121-134650696", "isbn": "9789283506676", "book_title": "Combat aircraft noise = le bruit g\u00e9n\u00e9r\u00e9 par les avions de combat", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110121-134650696", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech" }, { "agency": "Office of Naval Research (ONR)" }, { "agency": "Air Force Office of Scientific Research (AFOSR)" }, { "agency": "NASA" } ] }, "other_numbering_system": { "items": [ { "name": "Guggenheim Jet Propulsion Center" } ] }, "local_group": { "items": [ { "id": "Guggenheim-Jet-Propulsion-Center" }, { "id": "GALCIT" } ] }, "primary_object": { "basename": "331_Culick_FEC.pdf", "url": "https://authors.library.caltech.edu/records/8ej75-5jx95/files/331_Culick_FEC.pdf" }, "pub_year": "1992", "author_list": "Culick, F. E. C.; Paparizos, L.; et el." }, { "id": "https://authors.library.caltech.edu/records/aqpcg-f6c60", "eprint_id": 50558, "eprint_status": "archive", "datestamp": "2023-08-20 00:46:18", "lastmod": "2023-10-17 23:55:38", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Gilbrech-R-J", "name": { "family": "Gilbrech", "given": "R. J." } }, { "id": "Dimotakis-P-E", "name": { "family": "Dimotakis", "given": "P. E." } } ] }, "title": "Product Formation in Chemically-Reacting Turbulent Jets", "ispublished": "unpub", "full_text_status": "public", "note": "Copyright \u00a91992 by R. J. Gilbrech and P. E. Dimotaki. Published by the American Institute\nof Aeronautics and Astronautics, Inc. with permission.\n\nAIAA 92-0581.\n\nThis work was jaintly funded by the Gas Research Institute through Contracts\n5083-260-0878 and 5087-260-1467, and the Air Force Office of Scientific Research\nthrough Grants 83-0213 and 88-0155.\n\nPublished - product_formation.pdf
", "abstract": "Results from experiments performed in a newly-constructed High Pressure Combustion Facility are presented. The experiments described here are designed to\naddress Reynolds number effects on turbulent mixing and entrainment, and flame length in an axisymmetric, gas-phase turbulent reacting jet, in particular, over a\nlarge range of Reynolds numbers.", "date": "1992", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "id_number": "CaltechAUTHORS:20141020-131026134", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141020-131026134", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gas Research Institute", "grant_number": "5083-260-0878" }, { "agency": "Gas Research Institute", "grant_number": "5087-260-1467" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "83-0213" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "88-0155" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.1992-581", "primary_object": { "basename": "product_formation.pdf", "url": "https://authors.library.caltech.edu/records/aqpcg-f6c60/files/product_formation.pdf" }, "pub_year": "1992", "author_list": "Gilbrech, R. J. and Dimotakis, P. E." }, { "id": "https://authors.library.caltech.edu/records/4cfnq-p9x40", "eprint_id": 52233, "eprint_status": "archive", "datestamp": "2023-08-20 00:47:17", "lastmod": "2023-10-18 19:41:25", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Roshko-A", "name": { "family": "Roshko", "given": "Anatol" } } ] }, "title": "Uses of flow visualization in research", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1992 International Academic Press.", "abstract": "Flow visualization has important applications in engineering studies of complex flow fields and it is an\nindispensable tool in fluid-mechanics research. Some examples of the role which it has played in research\ndiscovery are discussed.", "date": "1992", "date_type": "published", "publisher": "International Academic Press", "place_of_pub": "Beijing", "pagerange": "3-11", "id_number": "CaltechAUTHORS:20141201-132549656", "isbn": "7800031861", "book_title": "Recent advances in experimental fluid mechanics : proceedings of the 1st International Conference on Experimental Fluid Mechanics, June 17-21, 1991, Chengdu, China", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141201-132549656", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Zhuang-F-G", "name": { "family": "Zhuang", "given": "F. G." } } ] }, "pub_year": "1992", "author_list": "Roshko, Anatol" }, { "id": "https://authors.library.caltech.edu/records/10cdj-fj275", "eprint_id": 21891, "eprint_status": "archive", "datestamp": "2023-08-20 00:42:49", "lastmod": "2024-01-13 00:09:02", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Culick-F-E-C", "name": { "family": "Culick", "given": "F. E. C." } }, { "id": "Yang-V", "name": { "family": "Yang", "given": "V." } } ] }, "title": "Prediction of the stability of unsteady motions in solid-propellant rocket motors", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 1990 by F. E. C. Culick and V. Yang. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission. The authors are indebted to S. I. Kim and M. Fuchs for their help in completing some of the calculations and to J. N. Levine for providing the\nnumerical code for the nonlinear combustion instability study. This work was partly supported by the California Institute of Technology and Pennsylvania State University.\n\nPublished - 335_Culick_FEC.pdf
", "abstract": "N/A", "date": "1992", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "place_of_pub": "Washington, DC", "pagerange": "719-779", "id_number": "CaltechAUTHORS:20110125-152359532", "isbn": "978-1-56347-014-1", "book_title": "Nonsteady Burning and Combustion Stability of Solid Propellants", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110125-152359532", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech" }, { "agency": "Pennsylvania State University" } ] }, "other_numbering_system": { "items": [ { "name": "Guggenheim Jet Propulsion Center" } ] }, "local_group": { "items": [ { "id": "Guggenheim-Jet-Propulsion-Center" }, { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "De-Luca-L", "name": { "family": "De-Luca", "given": "Luigi" } }, { "id": "Price-E-W", "name": { "family": "Price", "given": "Edward W." } }, { "id": "Summerfield-M", "name": { "family": "Summerfield", "given": "Martin" } } ] }, "primary_object": { "basename": "335_Culick_FEC.pdf", "url": "https://authors.library.caltech.edu/records/10cdj-fj275/files/335_Culick_FEC.pdf" }, "pub_year": "1992", "author_list": "Culick, F. E. C. and Yang, V." }, { "id": "https://authors.library.caltech.edu/records/3m4jp-cjn26", "eprint_id": 105950, "eprint_status": "archive", "datestamp": "2023-08-22 08:39:33", "lastmod": "2023-10-20 22:53:52", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Sturtevant-B", "name": { "family": "Sturtevant", "given": "B." } }, { "id": "Glicken-H", "name": { "family": "Glicken", "given": "H." } }, { "id": "Hill-L-G", "name": { "family": "Hill", "given": "L." } }, { "id": "Anilkumar-A-V", "name": { "family": "Anilkumar", "given": "A. V." } } ] }, "title": "Explosive volcanism in Japan and the United States: Gaining an understanding by shock tube experiments", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Volcano; Bandai-San St Helens; Eruption; Fragmentation", "note": "\u00a9 Springer-Verlag Berlin Heidelberg 1992.", "abstract": "On 15 July, 1888, Bandai Volcano in central Japan erupted explosively in a style which, in many aspects, was imitated by Mount. St. Helens nearly 100 years later. The episode began with a violent earthquake, and there was a major debris avalanche and many large explosions that resulted in the death of 461 people. The last and largest explosion was directed laterally across the landscape. The eruption and its aftermath were extremely well documented in the press, by scientists and by eye witnesses. We present some of the early photographs and paintings of the eruption of Bandai-San. The eruption of Mount. St. Helens on 18 May, 1980, documented with modern observational methods, caused a revolution in the understanding of explosive volcanism, and so led to a more detailed understanding of the eruption of Bandai Volcano. The information gathered a century ago serves now as an important resource. \n\nPhysical processes which cause the destructiveness of explosive eruptions include the energetic fragmentation of liquid magma into fire ash particles and ejection of the particles and liberated gases through the vent at supersonic speed. It is possible to study these processes at laboratory scale by using shock tube techniques. Impulsive, highly accelerating flows, in which the greater effect of earth's gravity under full scale conditions plays little role, can be generated by rapidly depressurizing volatile liquids or pressurized beds of solid particles. One experiment of each type is described. In the first, superheated refrigerants are used to simulate gas-rich magma, and the explosive vaporization that results ('evaporation wave') is studied as a model of magma fragmentation. In the second, it is shown that accelerating dense dusty gases are inherently unstable to density perturbations, and that the resulting flow experience density fluctuations of order 1000. Implications regarding the interpretation of volcanological deposits and blast effects are described.", "date": "1992", "date_type": "published", "publisher": "Springer Berlin Heidelberg", "place_of_pub": "Berlin, Heidelberg", "pagerange": "129-140", "id_number": "CaltechAUTHORS:20201009-102842916", "isbn": "9783642776502", "book_title": "Shock Waves", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201009-102842916", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Takayama-Kazuyoshi", "name": { "family": "Takayama", "given": "Kazuyoshi" } } ] }, "doi": "10.1007/978-3-642-77648-9_14", "pub_year": "1992", "author_list": "Sturtevant, B.; Glicken, H.; et el." }, { "id": "https://authors.library.caltech.edu/records/h2hsr-v1625", "eprint_id": 79705, "eprint_status": "archive", "datestamp": "2023-08-22 08:38:05", "lastmod": "2023-10-26 17:02:54", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "H." }, "orcid": "0000-0002-4903-8419" }, { "id": "Sturtevant-B", "name": { "family": "Sturtevant", "given": "B." } }, { "id": "B\u00e9langer-J", "name": { "family": "B\u00e9langer", "given": "J." } }, { "id": "Sanderson-S-R", "name": { "family": "Sanderson", "given": "S." } }, { "id": "Brouillette-M", "name": { "family": "Brouillette", "given": "M." } }, { "id": "Jenkins-M", "name": { "family": "Jenkins", "given": "M." } } ] }, "title": "Performance data of the new free-piston shock tunnel T5 at GALCIT", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Hypersonic facility; Shock tunnel", "note": "\u00a9 1992 Springer-Verlag Berlin Heidelberg.\n\nThis work was supported by ONR Grant N00014-90-J-1305, and NASA Grant NAG-1-1209. We would also like to thank Rocketdyne Division of Rockwell International Corporation for manpower support, particularly by Darlene Gieseking, for use of their high-speed video system, and for supplying the NARloy-Z for the nozzle throat insert.", "abstract": "A new free piston shock tunnel has been constructed at the Graduate Aeronautical Laboratories at Caltec. Compression tube length is 30 m and diameter 300 mm. Shock tube length is 12 m and diameter 90 mm. Piston mass is 150 kg and maximum diaphragm burst pressure is 130 MPa. Special features of this facility are that the pressure in the driver gas is monitered throughout the compression process until well after diaphragm rupture, and that the diaphragm burst pressure can be measured dynamically. An analysis of initial performance data including transient behavior of the flow over models is presented.", "date": "1992", "date_type": "published", "publisher": "Springer", "place_of_pub": "Berlin", "pagerange": "603-610", "id_number": "CaltechAUTHORS:20170801-143013008", "isbn": "978-3-642-77650-2", "book_title": "Shock Waves", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170801-143013008", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-90-J-1305" }, { "agency": "NASA", "grant_number": "NAG-1-1209" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Takayama-Kazuyoshi", "name": { "family": "Takayama", "given": "Kazuyoshi" } } ] }, "doi": "10.1007/978-3-642-77648-9_95", "pub_year": "1992", "author_list": "Hornung, H.; Sturtevant, B.; et el." }, { "id": "https://authors.library.caltech.edu/records/ack8r-qbt11", "eprint_id": 93079, "eprint_status": "archive", "datestamp": "2023-08-20 00:39:56", "lastmod": "2024-01-14 21:29:55", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Liu-Cheng", "name": { "family": "Liu", "given": "Cheng" } }, { "id": "Rosakis-A-J", "name": { "family": "Rosakis", "given": "Ares J." }, "orcid": "0000-0003-0559-0794" } ] }, "title": "Interpretation of optical caustic patterns obtained during unsteady crack growth: an analysis based on a higher-order transient expansion", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 1991 Society of Photo-Optical Instrumentation Engineers (SPIE).\n\nPublished - 814.pdf
", "abstract": "The optical caustic method is re-examined considering the presence of transient effects. Based on the higher-order asymptotic expansion provided by Freund and Rosakis, regarding the stress field near a non-uniformly propagating crack tip, the caustic mapping and the initial curve equations are derived. The dynamic stress intensity factor, K^d_I(t), is related to experimentally measurable quantities of the caustic pattern by an explicit expression. It is shown that the classical analysis of caustics is a special case of the new interpretation method. The Broberg problem is used as an example problem to check the feasibility of analysing caustics in the presence of higher-order transient terms. It is shown that the caustic patterns are sensitive to transient effects, and that use of the classical analysis of caustics in the interpretation of the optical patterns for this problem may result in large errors in the value of the stress intensity factor, especially at short times after initiation.", "date": "1991-12-01", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "814-825", "id_number": "CaltechAUTHORS:20190221-110520782", "isbn": "9780819406828", "book_title": "Second International Conference on Photomechanics and Speckle Metrology", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190221-110520782", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Chiang-Fu-Pen", "name": { "family": "Chiang", "given": "Fu-Pen" } } ] }, "doi": "10.1117/12.49532", "primary_object": { "basename": "814.pdf", "url": "https://authors.library.caltech.edu/records/ack8r-qbt11/files/814.pdf" }, "pub_year": "1991", "author_list": "Liu, Cheng and Rosakis, Ares J." }, { "id": "https://authors.library.caltech.edu/records/6xgdj-ghr74", "eprint_id": 93077, "eprint_status": "archive", "datestamp": "2023-08-20 00:39:47", "lastmod": "2024-01-14 21:29:51", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lambros-J-M", "name": { "family": "Lambros", "given": "J." } }, { "id": "Mason-J-J", "name": { "family": "Mason", "given": "J. J." } }, { "id": "Rosakis-A-J", "name": { "family": "Rosakis", "given": "A. J." }, "orcid": "0000-0003-0559-0794" } ] }, "title": "Experimental investigation of dynamic mixed-mode fracture initiation", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 1991 Society of Photo-Optical Instrumentation Engineers (SPIE). \n\nWe would like to thank Prof. L.B. Freund and Dr. Y.J. Lee for their many helpful discussions and for making their numerical data available to us prior to publication. We would also like to thank Dr. H. Tippur for his help and advice given in the early stages of this study. Finally, the support of ONR through Contract N00014-90-J-1340 is gratefully acknowledged.\n\nPublished - 70.pdf
", "abstract": "The use of a coherent gradient sensing (CGS) apparatus is explored in dynamic fracture mechanics investigations. The ability of the method to accurately quantify mixed-mode crack tip deformation fields is tested under dynamic loading conditions. The specimen geometry and loading follow that of Lee and Freund who give the theoretical and numerical mixed mode K values as a function of time for the testing conditions. The CGS system's measurements of KI and KII are compared with the predicted results, and good agreement is found.", "date": "1991-12-01", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "70-83", "id_number": "CaltechAUTHORS:20190221-110520608", "isbn": "9780819406828", "book_title": "Second International Conference on Photomechanics and Speckle Metrology", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190221-110520608", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-90-J-1340" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Chiang-Fu-Pen", "name": { "family": "Chiang", "given": "Fu-Pen" } } ] }, "doi": "10.1117/12.49481", "primary_object": { "basename": "70.pdf", "url": "https://authors.library.caltech.edu/records/6xgdj-ghr74/files/70.pdf" }, "pub_year": "1991", "author_list": "Lambros, J.; Mason, J. J.; et el." }, { "id": "https://authors.library.caltech.edu/records/cyp7x-a0095", "eprint_id": 93078, "eprint_status": "archive", "datestamp": "2023-08-20 00:39:52", "lastmod": "2024-01-14 21:29:53", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Tippur-H-V", "name": { "family": "Tippur", "given": "Hareesh V." } }, { "id": "Krishnaswamy-S", "name": { "family": "Krishnaswamy", "given": "Sridhar" } }, { "id": "Rosakis-A-J", "name": { "family": "Rosakis", "given": "Ares J." }, "orcid": "0000-0003-0559-0794" } ] }, "title": "Crack-tip deformation field measurements using coherent gradient sensing", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 1991 Society of Photo-Optical Instrumentation Engineers (SPIE).\n\nPublished - 176.pdf
", "abstract": "A real time, full field, lateral shearing interferometry - coherent gradient sensing (CGS) - has recently been developed for investigating fracture in transparent and opaque solids. The resulting interference patterns are related to the mechanical fields by means of a first order diffraction analysis. The method has been successfully applied to quasi-static and dynamic crack tip deformation field mapping in homogeneous and bimaterial fracture specimens.", "date": "1991-12-01", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_pub": "Bellingham, WA", "pagerange": "176-191", "id_number": "CaltechAUTHORS:20190221-110520688", "isbn": "9780819406828", "book_title": "Second International Conference on Photomechanics and Speckle Metrology", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190221-110520688", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Chiang-Fu-Pen", "name": { "family": "Chiang", "given": "Fu-Pen" } } ] }, "doi": "10.1117/12.49513", "primary_object": { "basename": "176.pdf", "url": "https://authors.library.caltech.edu/records/cyp7x-a0095/files/176.pdf" }, "pub_year": "1991", "author_list": "Tippur, Hareesh V.; Krishnaswamy, Sridhar; et el." }, { "id": "https://authors.library.caltech.edu/records/tg651-hx139", "eprint_id": 21050, "eprint_status": "archive", "datestamp": "2023-08-20 00:05:25", "lastmod": "2023-10-20 23:43:03", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Culick-F-E-C", "name": { "family": "Culick", "given": "F. E. C." } }, { "id": "Lin-W-H", "name": { "family": "Lin", "given": "W. H." } }, { "id": "Jahnke-C-C", "name": { "family": "Jahnke", "given": "C. C." } }, { "id": "Sterling-J-D", "name": { "family": "Sterling", "given": "J. D." } } ] }, "title": "Modeling for Active Control of Combustion and Thermally Driven Oscillations", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 1991, IEEE. Date of Current Version :10 March 2009. \nThis work was partially supported by the Office of Naval\nResearch, Contract N00014-89-J-1753, the Air Force Office of\nScientific Research, Grant No. 90-0188 and by Caltech funds.\n\nPublished - 318_Culick_FEC_1991.pdf
", "abstract": "Organized oscillations excited and sustained by high densities of energy release in combustion chambers have long caused serious problems in development of propulsion systems. The amplitudes often become sufficiently large to cause unacceptable structural vibrations. Because the oscillations are self-excited, they reach limiting amplitudes (limit cycles) only because of the action of nonlinear processes. Traditionally, satisfactory behavior\nhas been achieved through a combination of trial-and-error\ndesign and testing, with control always involving passive means: geometrical modifications, changes of propellant composition, or devices to enhance dissipation of acoustic energy. Active control has been applied only to small-scale laboratory devices, but the limited success suggests the possibility of serious applications to full-scale propulsion systems. Realization of that potential rests on further experimental work, combined with deeper understanding of the mechanisms causing the oscillations and of the physical behavior of the systems. Effective design of active control systems will require faithful modeling of the relevant processes over broad frequency ranges covering the spectra of natural modes. This paper will cover the general character of the linear and nonlinear behavior of combustion systems, with special attention to acoustics and the mechanisms of excitation.\nThe discussion is intended to supplement the paper by Doyle et al. concerned primarily with controls issues and the observed behavior of simple laboratory devices.", "date": "1991-06", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "2939-2948", "id_number": "CaltechAUTHORS:20101130-075321569", "isbn": "0-87942-565-2", "book_title": "Proceedings of the 1991 American Control Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20101130-075321569", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research", "grant_number": "N00014-89-J-1753" }, { "agency": "Air Force Office of Scientific Research", "grant_number": "90-0188" }, { "agency": "Caltech funds" } ] }, "other_numbering_system": { "items": [ { "name": "Guggenheim Jet Propulsion Center" } ] }, "local_group": { "items": [ { "id": "Guggenheim-Jet-Propulsion-Center" }, { "id": "GALCIT" } ] }, "primary_object": { "basename": "318_Culick_FEC_1991.pdf", "url": "https://authors.library.caltech.edu/records/tg651-hx139/files/318_Culick_FEC_1991.pdf" }, "pub_year": "1991", "author_list": "Culick, F. E. C.; Lin, W. H.; et el." }, { "id": "https://authors.library.caltech.edu/records/xb8vb-e1d47", "eprint_id": 21902, "eprint_status": "archive", "datestamp": "2023-08-19 23:25:13", "lastmod": "2023-10-23 15:29:23", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Culick-F-E-C", "name": { "family": "Culick", "given": "F. E. C." } } ] }, "title": "Combustion Instabilities and Rayleigh's Criterion", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1991 Springer-Verlag.", "abstract": "In 1878, Lord Rayleigh formulated his criterion to explain several \nexamples of acoustic waves excited and maintained by heat addition. It is a\nqualitative explanation successfully capturing the essence of the phenomena\nbut not providing a basis for quantitative predictions. The widespread appeal\nof Rayleigh's criterion merits placing this important result on a more rigorous\nbasis. To do so requires careful formulation grounded in the theory of small\namplitude motions in a compressible fluid. In this chapter, we review the\nconstruction of an approximate analysis and establish the equivalence of\nRayleigh's criterion and the condition for linear stability of small amplitude\nmotions. Thus Rayleigh's criterion is formulated explicitly in the context of\nan analysis applicable to any combustion chamber. Some results are discussed\nfor both linear and nonlinear motions. Recent experimental results discussed\nby others suggest that the criterion may offer a practical means for investigating\nthe causes of instabilities in propulsion systems.", "date": "1991", "date_type": "published", "publisher": "Springer-Verlag", "place_of_pub": "New York", "pagerange": "135-151", "id_number": "CaltechAUTHORS:20110127-073132186", "isbn": "0-387-97417-2", "book_title": "Modern Research Topics in Aerospace Propulsion: in honor of Corrado Casci", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110127-073132186", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "name": "Guggenheim Jet Propulsion Center" } ] }, "local_group": { "items": [ { "id": "Guggenheim-Jet-Propulsion-Center" }, { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Angelino-G", "name": { "family": "Angelino", "given": "G." } }, { "id": "DeLuca-L", "name": { "family": "DeLuca", "given": "L." } }, { "id": "Sirignano-W-A", "name": { "family": "Sirignano", "given": "W. A." } } ] }, "pub_year": "1991", "author_list": "Culick, F. E. C." }, { "id": "https://authors.library.caltech.edu/records/tj4c7-7ng42", "eprint_id": 52234, "eprint_status": "archive", "datestamp": "2023-08-19 23:29:29", "lastmod": "2024-01-13 16:12:45", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Roshko-A", "name": { "family": "Roshko", "given": "Anatol" } } ] }, "title": "The mixing transition in free shear flows", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1991 Springer. \n\nMuch of the experimental work used for reference here was supported by the U. S. Office of Naval Research and the Air Force Office of Scientific Research. Discussions with P. Bernal and R. Breidenthal provided helpful clarifications.", "abstract": "The term \"mixing transition\" denotes an increase in molecular mixedness observed in a\nshear How which has earlier experienced the conventional (momentum) transition from laminar\nflow. First defined by Konrad (1976), from measurements of concentration in a free shear layer,\nthe transition has been described and measured by a number of other methods, in particular by\nflow visualization, by measurement of chemical reaction product and by hot-wire anemometry, in\naqueous as well as gaseous flows. In this presentation we review some of the measurements\nand try to assess what insight they may give on several questions that occur. 1. What is the\nrelation of the mixing transition to Reynolds number and to other events: the momentum transition;\nvortex pairing; development of streamwise vortex structure? 2. How much does interfacial\narea increase during the transition? 3. How fast docs this occur? 4. Docs chaotic advection\nplay a role? The answers arc tentative and incomplete.", "date": "1991", "date_type": "published", "publisher": "Plenum Press", "place_of_pub": "New York, NY", "pagerange": "3-11", "id_number": "CaltechAUTHORS:20141201-133432952", "isbn": "0306440148", "book_title": "The global geometry of turbulence : impact of nonlinear dynamics", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141201-133432952", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)" }, { "agency": "Air Force Office of Scientific Research (AFOSR)" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Jim\u00e9nez-J", "name": { "family": "Jim\u00e9nez", "given": "Javier" } } ] }, "doi": "10.1007/978-1-4615-3750-2_1", "pub_year": "1991", "author_list": "Roshko, Anatol" }, { "id": "https://authors.library.caltech.edu/records/sp1zh-vv293", "eprint_id": 79426, "eprint_status": "archive", "datestamp": "2023-08-19 23:31:15", "lastmod": "2023-10-26 16:12:23", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Fric-T-F", "name": { "family": "Fric", "given": "T. F." } }, { "id": "Roshko-A", "name": { "family": "Roshko", "given": "A." } } ] }, "title": "Structure in the Near Field of the Transverse Jet", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1991 Springer-Verlag Berlin Heidelberg.\n\nWe would like to thank Professor H. G. Hornung for many helpful discussions on the issue of vorticity generation. This work was partially supported by ONR contract #N00014-85-K-0646.", "abstract": "Photographs of a jet issuing from a wall into a crossflow display the four types of vortical structures which exist in the near field: namely, the jet shear layer vortices, the nascent far field vortex pair, the near-wall horseshoe vortices, and a system of vortices in the wake of the jet. It is shown that the wake vorticity is not \"shed\" from the jet but is formed from vorticity which originated in the wall boundary layer. The sources of vorticity for the other types of structures are also briefly discussed.", "date": "1991", "date_type": "published", "publisher": "Springer", "place_of_pub": "Berlin", "pagerange": "225-237", "id_number": "CaltechAUTHORS:20170726-131022892", "isbn": "978-3-642-76089-1", "book_title": "Turbulent Shear Flows 7", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170726-131022892", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-85-K-0646" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Durst-F", "name": { "family": "Durst", "given": "Franz" } }, { "id": "Launder-B-E", "name": { "family": "Launder", "given": "Brian E." } }, { "id": "Reynolds-W-C", "name": { "family": "Reynolds", "given": "William C." } }, { "id": "Schmidt-F-W", "name": { "family": "Schmidt", "given": "Frank W." } }, { "id": "Whitelaw-J-H", "name": { "family": "Whitelaw", "given": "James H." } } ] }, "doi": "10.1007/978-3-642-76087-7_17", "pub_year": "1991", "author_list": "Fric, T. F. and Roshko, A." }, { "id": "https://authors.library.caltech.edu/records/gpm7y-wza86", "eprint_id": 52236, "eprint_status": "archive", "datestamp": "2023-08-19 23:29:36", "lastmod": "2024-01-13 16:12:46", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Roshko-A", "name": { "family": "Roshko", "given": "A." } }, { "id": "Kleiser-L", "name": { "family": "Kleiser", "given": "L." } }, { "id": "Moin-Parviz", "name": { "family": "Moin", "given": "P." }, "orcid": "0000-0002-0491-7065" } ] }, "title": "Panel Discussion: Direct Numerical Simulation or Experiments?", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1991 Springer.", "abstract": "I have been tapped as the moderator for this panel, and I hope that everybody\nelse is prepared to say a few things. I think that our job as panellists is to provoke a little discussion from the audience, and I would like to say a few words to get things started. First,\nto clarify the subject of the discussion a little bit, I think that what is implied in the title by\n\"experiments\" are laboratory experiments. I think that the direct numerical simulations are, in\nfact, also experiments, and that we should be talking about using direct numerical simulation\nin the same way that we use the laboratory, to produce flows that can be studied and brought\ninto the research picture.", "date": "1991", "date_type": "published", "publisher": "Plenum Press", "place_of_pub": "New York, NY", "pagerange": "331-339", "id_number": "CaltechAUTHORS:20141201-135146578", "isbn": "0306440148", "book_title": "The global geometry of turbulence : impact of nonlinear dynamics", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141201-135146578", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Jim\u00e9nez-J", "name": { "family": "Jim\u00e9nez", "given": "Javier" } } ] }, "doi": "10.1007/978-1-4615-3750-2_30", "pub_year": "1991", "author_list": "Roshko, A.; Kleiser, L.; et el." }, { "id": "https://authors.library.caltech.edu/records/pnyep-ka188", "eprint_id": 42108, "eprint_status": "archive", "datestamp": "2023-08-19 22:08:41", "lastmod": "2023-10-25 15:38:50", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Dabiri-D", "name": { "family": "Dabiri", "given": "Dana" } }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "Morteza" } } ] }, "title": "Digital Particle Image Thermometry", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1990 Lissabon.\n\nThis work is sponsored bye the Defense Advanced Research Project\nAgency-ACMP through the URI program under contract number DARPA/ACMP\nN00014-18-k-0758 The authors would like to thank Mr. Alex Weigand for his\nassistance in the heated vortex-ring experiment.", "abstract": "A computerized flow visualization technique capable of automatically\nquantifying the temperature field in a two-dimensional cross section of a flow field\nis described. The temperature sensors used are fast-response temperature-sensitive\nmicro-encapsulated liquid crystal particles. Illuminating the flow by a thin sheet\nof white light, the reflected colors from the liquid-crystal particles were captured\nthrough a 3-chip video color camera and stored onto a videotape for subsequent data\nprocessing. The temperature flow field was obtained through an automatic color-temperature\ncalibration scheme in HSI rather than RGB space, thus allowing for\ndata processing of approximately one-third the time of RGB processing. The\ntechnique is finally applied to the study of a heated vortex-ring and some\npreliminary results are discussed.", "date": "1990", "date_type": "published", "publisher": "Lissabon", "id_number": "CaltechAUTHORS:20131029-094410182", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131029-094410182", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "DARPA/ACMP URI Program", "grant_number": "N00014-18-K-0758" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "pub_year": "1990", "author_list": "Dabiri, Dana and Gharib, Morteza" }, { "id": "https://authors.library.caltech.edu/records/3f8xw-pwx07", "eprint_id": 52238, "eprint_status": "archive", "datestamp": "2023-08-19 22:11:52", "lastmod": "2024-01-13 16:12:50", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Aubry-N", "name": { "family": "Aubry", "given": "Nadine" } }, { "id": "Perry-T", "name": { "family": "Perry", "given": "Tony" } }, { "id": "Lumley-J-L", "name": { "family": "Lumley", "given": "John" } }, { "id": "Holmes-P-J", "name": { "family": "Holmes", "given": "Philip" } }, { "id": "Frisch-U", "name": { "family": "Frisch", "given": "Uriel" } }, { "id": "Sudan-R", "name": { "family": "Sudan", "given": "Ravi" } }, { "id": "Moffatt-K", "name": { "family": "Moffatt", "given": "Keith" } }, { "id": "Phillips-B", "name": { "family": "Phillips", "given": "Bill" } }, { "id": "Marsden-J-E", "name": { "family": "Marsden", "given": "Jerry" } }, { "id": "George-B", "name": { "family": "George", "given": "Bill" } }, { "id": "Roshko-A", "name": { "family": "Roshko", "given": "Anatol" } }, { "id": "Hussain-F", "name": { "family": "Hussain", "given": "Fazle" } }, { "id": "Reynolds-B", "name": { "family": "Reynolds", "given": "Bill" } }, { "id": "Leonard-A", "name": { "family": "Leonard", "given": "Tony" } }, { "id": "Moin-Parviz", "name": { "family": "Moin", "given": "Parviz" }, "orcid": "0000-0002-0491-7065" } ] }, "title": "Discussion on the utility of dynamical systems approach", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1990 Springer.", "abstract": "I have a rather provocative question to ask the speakers. What I am wondering is:\nWhen you apply the proper orthogonal decomposition - I know this is a procedure\nyou use and it is probably standard - you remove the mean flow and you only look at\nthe perturbations. Why do not you include the mean flow, because if you did you\nwould suppress the cubic terms, and also you would be getting something that would\nbe closer to what people call coherent structures, such as hairpin vortices.", "date": "1990", "date_type": "published", "publisher": "Springer-Verlag", "place_of_pub": "Berlin", "pagerange": "292-305", "id_number": "CaltechAUTHORS:20141201-140640640", "isbn": "978-3-540-52535-6", "book_title": "Whither Turbulence? Turbulence at the Crossroads : Proceedings of a Workshop Held at Cornell University, Ithaca, NY, March 22\u201324, 1989", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141201-140640640", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Lumley-J-L", "name": { "family": "Lumley", "given": "John L." } } ] }, "doi": "10.1007/3-540-52535-1_50", "pub_year": "1990", "author_list": "Aubry, Nadine; Perry, Tony; et el." }, { "id": "https://authors.library.caltech.edu/records/teqz9-6x245", "eprint_id": 52241, "eprint_status": "archive", "datestamp": "2023-08-19 22:12:06", "lastmod": "2024-01-13 16:12:54", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Smits-A-J", "name": { "family": "Smits", "given": "Alexander J." } }, { "id": "Stull-R", "name": { "family": "Stull", "given": "Roland" } }, { "id": "Coantic-M", "name": { "family": "Coantic", "given": "Michel" } }, { "id": "Traugott-S", "name": { "family": "Traugott", "given": "Stephen" } }, { "id": "Mathieu-J", "name": { "family": "Mathieu", "given": "Jean" } }, { "id": "Shih-T-H", "name": { "family": "Shih", "given": "Tsan-Hsing" } }, { "id": "Narasimha-R", "name": { "family": "Narasimha", "given": "Roddam" } }, { "id": "Launder-B", "name": { "family": "Launder", "given": "Brian" } }, { "id": "El-Tahry-S", "name": { "family": "El Tahry", "given": "Sherif" } }, { "id": "Rodi-W", "name": { "family": "Rodi", "given": "Wolfgang" } }, { "id": "Reynolds-B", "name": { "family": "Reynolds", "given": "Bill" } }, { "id": "George-B", "name": { "family": "George", "given": "Bill" } }, { "id": "Roshko-A", "name": { "family": "Roshko", "given": "Anatol" } }, { "id": "Bilger-B", "name": { "family": "Bilger", "given": "Bob" } }, { "id": "Herring-J", "name": { "family": "Herring", "given": "Jack" } }, { "id": "Speziale-C", "name": { "family": "Speziale", "given": "Charles" } }, { "id": "Nagib-H-M", "name": { "family": "Nagib", "given": "Hassan" } }, { "id": "Cantwell-B", "name": { "family": "Cantwell", "given": "Brian" } }, { "id": "Wyngaard-J", "name": { "family": "Wyngaard", "given": "John" } }, { "id": "Bradshaw-P", "name": { "family": "Bradshaw", "given": "Peter" } }, { "id": "Lumley-J-L", "name": { "family": "Lumley", "given": "John" } } ] }, "title": "Discussion on \"phenomenological modeling: Present and future\"", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1990 Springer.", "abstract": "This afternoon all of the models that we have heard fall in the same\nclass; namely, local closures. First-order local closure (K-theory or\neddy diffusivity) models the momentum fluxes as down-gradient of\nthe mean momentum. The second-order local closure models the\nthird moments as down-gradient of the local second moments, or\nlocal mean variables. \n\nThere is another completely different class of modeling or class of\nclosure, and that is non-local turbulence closure. I mentioned\nbefore about the transilient matrix that describes the mixing\nbetween different points separated a finite distance in space. One\ncan parameterize this matrix in terms of mean flow state or mean\nflow instability. When you do that, you can then make forecasts of\nthe mean field in a turbulent flow that takes into account this nonlocal\nmixing. \n\nThat has been done. For the ocean, we found results as good as\nthird-order local closure. For the atmosphere, results were as good\nas second-order local closure. We've used it in three-dimensional\nweather forecast models covering the whole United States. This is a\nnew concept of non-local closure, which is different from all the\nother local closures. \n\nWhen would you want to consider using a non-local kind of closure?\nWell, if any of you are dealing with turbulent flow that has a\nspectrum of eddy sizes where your greatest energy is in the largest\nwavelengths, or if you are dealing with turbulent flow that has large\nstructures in it that are causing non-local mixing, then you might\nwant to consider a non-local turbulence closure.", "date": "1990", "date_type": "published", "publisher": "Springer-Verlag", "place_of_pub": "Berlin", "pagerange": "517-535", "id_number": "CaltechAUTHORS:20141201-142720632", "isbn": "978-3-540-52535-6", "book_title": "Whither Turbulence? Turbulence at the Crossroads : Proceedings of a Workshop Held at Cornell University, Ithaca, NY, March 22\u201324, 1989", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141201-142720632", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Lumley-J-L", "name": { "family": "Lumley", "given": "John L." } } ] }, "doi": "10.1007/3-540-52535-1_66", "pub_year": "1990", "author_list": "Smits, Alexander J.; Stull, Roland; et el." }, { "id": "https://authors.library.caltech.edu/records/gkxxs-s3b32", "eprint_id": 42889, "eprint_status": "archive", "datestamp": "2023-08-19 22:08:49", "lastmod": "2023-10-25 23:07:45", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bartsch-D-U", "name": { "family": "Bartsch", "given": "Dirk-Uwe" } }, { "id": "Bille-J-F", "name": { "family": "Bille", "given": "Josef F." } }, { "id": "Dreher-A-W", "name": { "family": "Dreher", "given": "Andreas W." } }, { "id": "Intaglietta-M", "name": { "family": "Intaglietta", "given": "Marcos" } }, { "id": "Gharib-M", "name": { "family": "Gharib", "given": "Morteza" }, "orcid": "0000-0003-0754-4193" }, { "id": "Freeman-W-R", "name": { "family": "Freeman", "given": "William R." }, "orcid": "0000-0003-3559-5270" } ] }, "title": "Analysis of the Human Macula by Confocal Laser Tomography", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1990 Quintessenz Verlags-GmbH, M\u00fcnchen.", "abstract": "Laser scanning tomography was used to\nstudy the surface of the diseased and normal\nmacula in the human eye. The confocal arrangement\nof the laser tomographic scanner\npermits the examination of the retinal topography\nin the axis perpendicular to the\nretinal surface. It was found that the normal\nmacular surface as seen in histological preparations\ncan be reconstructed in humans\nwith the laser tomographic scanner. A polarization\npattern can be observed in the\narea of Henle's fiber layer. We were able\nto reproducibly image a brush-like pattern\nwith the circular polarized laser light in\nhealthy eyes of 25 patients. In contrast, we\ndid not observe it in eyes with structural\nchanges of the macular tissue, indicating\nthat loss of the brush-like phenomena may\nbe an early and sensitive indication of macular\ndiseases. In diseased eyes we were\nable to assess structural abnormalities, such\nas macular holes, laser scars, macular\nbranch vein occlusion and macular edema.\nThe laser tomographic scanner offers a new\nmethod to determine the topography of the\ninternal limiting membrane in the macular\narea.", "date": "1990", "date_type": "published", "publisher": "Quintessenz", "place_of_pub": "M\u00fcnchen, Germany", "pagerange": "215-223", "id_number": "CaltechAUTHORS:20131209-081205363", "isbn": "9783928036016", "book_title": "Scanning laser ophthalmoscopy and tomography", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131209-081205363", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Nasemann-J-E", "name": { "family": "Nasemann", "given": "Joachim E." } }, { "id": "Burk-R-O-W", "name": { "family": "Burk", "given": "Reinhard O. W." } }, { "id": "Webb-R-H", "name": { "family": "Webb", "given": "Robert H." } } ] }, "pub_year": "1990", "author_list": "Bartsch, Dirk-Uwe; Bille, Josef F.; et el." }, { "id": "https://authors.library.caltech.edu/records/fyqca-x1y88", "eprint_id": 52240, "eprint_status": "archive", "datestamp": "2023-08-19 22:11:59", "lastmod": "2024-01-13 16:12:52", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Roshko-A", "name": { "family": "Roshko", "given": "A." } } ] }, "title": "Phenomenological modeling: Present and future. Comment 1", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1990 Springer.", "abstract": "Professor Launder's position paper on phenomenological modelling is an impressive survey and valuable account of the status of second-moment closure, principally as applied to Reynolds Stresses. In this respect, it supplements and updates the monograph of Professor Rodi (1980), in which the emphasis is on the status of first-order closures, in particular the \u03ba-\u03b5 model, as of 10 years ago.\nBetween them the two works provide an excellent reference source containing the equations; the rationale for modelling decisions that are made; tables of the constants that have been selected; displays of flow computations and their comparison with experimental measurements for a varied number of flows; and extensive reference lists.", "date": "1990", "date_type": "published", "publisher": "Springer-Verlag", "place_of_pub": "Berlin", "pagerange": "486-489", "id_number": "CaltechAUTHORS:20141201-142123436", "isbn": "978-3-540-52535-6", "book_title": "Whither Turbulence? Turbulence at the Crossroads : Proceedings of a Workshop Held at Cornell University, Ithaca, NY, March 22\u201324, 1989", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141201-142123436", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Lumley-J-L", "name": { "family": "Lumley", "given": "John L." } } ] }, "doi": "10.1007/3-540-52535-1_63", "pub_year": "1990", "author_list": "Roshko, A." }, { "id": "https://authors.library.caltech.edu/records/w5hwp-9me27", "eprint_id": 105959, "eprint_status": "archive", "datestamp": "2023-08-22 07:05:05", "lastmod": "2024-01-15 18:13:15", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hill-L-G", "name": { "family": "Hill", "given": "L. G." } }, { "id": "Sturtevant-B", "name": { "family": "Sturtevant", "given": "B." } } ] }, "title": "An Experimental Study of Evaporation Waves in a Superheated Liquid", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Reservoir Pressure; Absolute Threshold; Test Liquid; Superheated Liquid; Exit Pressure", "note": "\u00a9 Springer-Verlag Berlin Heidelberg 1990. \n\nThis work was supported by the National Science Foundation under research grant #EAR-8512724. L. G. H. was supported in part by a fellowship from Caltech's Program in Advanced Technologies, sponsored by Aerojet General, General Motors, and TRW, and by a fellowship from the ARCS foundation.", "abstract": "The dynamical behavior governing the propagation of evaporation waves in chlorinated fluorocarbons is studied in a constant-diameter vertical glass test cell which exhausts into a large, low-pressure reservoir. Care is taken to suppress heterogeneous nucleation within the liquid column. The test liquid is initially in equilibrium with its own vapor, sealed by a foil diaphragm. Upon diaphragm rupture, a series of expansion waves depressurizes the liquid to approximately the reservoir pressure, during which nucleation and subsequent rapid vaporization begin at the free surface. After an approximately 10 ms long start-up transient, a quasi-steady process develops during which the wavefront propagates into the stagnant liquid column at constant average velocity, generating a nonuniform high-speed two-phase flow. The leading edge of the wavefront consists of smooth and rough bubbles with maximum diameters of order 1 mm and characteristic lifetimes of order 1 ms. High speed movies show that the nucleation rate is both spatially nonuniform and temporally nonsteady, which leads to significant unsteadiness in the propagation of the wave. Fragmentation of the liquid into fine droplets occurs primarily as the result of the violent break-up of the leading-edge bubbles coincident with explosive bursts of aerosol, which occur in the region extending about 1 cm downstream of the leading edge bubble layer. These two processes appear to be mutually interactive. Three distinct modes of flow initiation are observed depending on the liquid superheat. Moreover, a self-initiation threshold is observed, below which waves do not occur. We observe that waves can propagate at slightly lower superheats if they are started artificially. However, an absolute threshold for wave propagation exists which is related to the nonsteady processes alluded to above.", "date": "1990", "date_type": "published", "publisher": "Springer Berlin Heidelberg", "place_of_pub": "Berlin, Heidelberg", "pagerange": "25-37", "id_number": "CaltechAUTHORS:20201009-102843834", "isbn": "9783642835896", "book_title": "Adiabatic Waves in Liquid-Vapor Systems", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201009-102843834", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-8512724" }, { "agency": "Caltech Program in Advanced Technologies" }, { "agency": "ARCS Foundation" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Meier-G-E-A", "name": { "family": "Meier", "given": "Gerd E. A." } }, { "id": "Thompson-P-A", "name": { "family": "Thompson", "given": "Philip A." } } ] }, "doi": "10.1007/978-3-642-83587-2_3", "pub_year": "1990", "author_list": "Hill, L. G. and Sturtevant, B." }, { "id": "https://authors.library.caltech.edu/records/hq7y9-tt295", "eprint_id": 105937, "eprint_status": "archive", "datestamp": "2023-08-22 06:11:50", "lastmod": "2024-01-15 18:12:51", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "H. G." }, "orcid": "0000-0002-4903-8419" } ] }, "title": "Concluding Remarks", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Wind Tunnel; Total Pressure Loss; Delta Wing; Subjective View; Boundary Layer Effect", "note": "\u00a9 Springer-Verlag Berlin Heidelberg 1989.", "abstract": "The following remarks represent a subjective view of this symposium. The boundary conditions imposed on them also make the resolution poor.", "date": "1989", "date_type": "published", "publisher": "Springer Berlin Heidelberg", "place_of_pub": "Berlin, Heidelberg", "pagerange": "501-504", "id_number": "CaltechAUTHORS:20201008-131242531", "isbn": "9783642835865", "book_title": "Symposium Transsonicum III", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201008-131242531", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Zierep-J", "name": { "family": "Zierep", "given": "J." } }, { "id": "Oertel-H-Jr", "name": { "family": "Oertel", "given": "H., Jr." } } ] }, "doi": "10.1007/978-3-642-83584-1_40", "pub_year": "1989", "author_list": "Hornung, H. G." }, { "id": "https://authors.library.caltech.edu/records/fg5px-eyz12", "eprint_id": 50588, "eprint_status": "archive", "datestamp": "2023-08-19 21:09:06", "lastmod": "2024-01-13 16:10:18", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Dimotakis-P-E", "name": { "family": "Dimotakis", "given": "Paul E." } } ] }, "title": "Turbulent shear layer mixing with fast chemical reactions", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 1987 Springer-Verlag.\n\nThis work is part of a larger effort to investigate mixing and combustion in turbulent shear flows, sponsored by the Air Force Office of Scientific Research Contract No. F49620-79-C-01059 and Grant No. AFOSR-83-0213, whose support is gratefully acknowledged.", "abstract": "A model is proposed for calculating molecular mixing and chemical reactions in fully developed turbulent shear layers, in the limit of infinitely fast chemical kinetics and negligible heat release. The model is based on the assumption that the topology of the interface\nbetween the two entrained reactants in the layer, as well as the strain field associated with it, can be described by the similarity laws of the Kolmogorov cascade. The calculation estimates the integrated volume fraction across the layer occupied by the chemical product, as a function of the stoichiometric mixture ratio of the reactants carried by the free streams, the velocity ratio of the shear\nlayer, the local Reynolds number, and the Schmidt number of the flow. The results are in good agreement with measurements of the volume fraction occupied by the molecularly mixed fluid in a turbulent shear layer and the amount of chemical product, in both gas phase and liquid\nphase chemically reacting shear layers.", "date": "1989", "date_type": "published", "publisher": "Springer-Verlag", "place_of_pub": "New York, NY", "pagerange": "417-485", "id_number": "CaltechAUTHORS:20141020-163227204", "isbn": "0387968873", "book_title": "Turbulent Reactive Flows", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141020-163227204", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "F49620-79-C-0159" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "AFOSR-83-0213" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Borghi-R", "name": { "family": "Borghi", "given": "R." } }, { "id": "Murthy-S-N-B", "name": { "family": "Murthy", "given": "S. N. B." } } ] }, "doi": "10.1007/978-1-4613-9631-4_23", "pub_year": "1989", "author_list": "Dimotakis, Paul E." }, { "id": "https://authors.library.caltech.edu/records/r8gpc-ajy15", "eprint_id": 418, "eprint_status": "archive", "datestamp": "2023-08-22 06:08:48", "lastmod": "2024-01-11 23:03:56", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Knauss-W-G", "name": { "family": "Knauss", "given": "W. G." } } ] }, "title": "Time dependent fracture of polymers", "ispublished": "unpub", "full_text_status": "public", "keywords": "Fracture; polymer fracture; time dependence; viscoelasticity; plastics", "note": "This work was supported in part by the Office of Naval Research and by DARPA, Dr. L. Peebles technical monitor; the work was supported in part by the Program of Advanced Technologies at the California Institute of Technology with the industrial participants Aerojet General, General Motors and TRW. The writer is grateful to the assistance of several of his graduate students in the preparation of this manuscript, in particular G. Losi, T. Minahen, G. Pulos, P. Washabaugh, with D. Phillips as the secretary/typist.\n\nPublished - KNAafr89.pdf
", "abstract": "The fracture behavior of polymers is reviewed with emphasis on the time dependent aspects of the problem. Following a delineation of the history of crack propagation investigations in linearly viscoelastic materials, the effects of temperature and solvent environment are examined besides the special effects arising from fatigue loading. These phenomena are examined for both crosslinked and uncrosslinked polymers. Some special consideration is given to the phenomena connected with craze formation in amorphous homopolymers as well as in crystalline materials as exemplified by polyethylene. Finally, status of analytical tools and formulations of fracture problems involving non-linearly viscoelastic material behavior is delineated by means of some examples.", "date": "1989", "date_type": "published", "publisher": "Pergamon Press", "place_of_pub": "New York", "pagerange": "2683-2711", "id_number": "CaltechAUTHORS:KNAafr89", "isbn": "0080343430", "book_title": "Advances in fracture research : proceedings of the 7th International Conference on Fracture (ICF-7), Houston, Tex., 20-24 March 1989", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:KNAafr89", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research" }, { "agency": "DARPA" }, { "agency": "Program of Advanced Technologies at Caltech" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "name": { "family": "Salama", "given": "K." } }, { "name": { "family": "Ravi-Chandar", "given": "K." } }, { "name": { "family": "Taplin", "given": "D. M. R." } }, { "name": { "family": "Rama Rao", "given": "P." } } ] }, "primary_object": { "basename": "KNAafr89.pdf", "url": "https://authors.library.caltech.edu/records/r8gpc-ajy15/files/KNAafr89.pdf" }, "pub_year": "1989", "author_list": "Knauss, W. G." }, { "id": "https://authors.library.caltech.edu/records/wvc5y-a5d43", "eprint_id": 84226, "eprint_status": "archive", "datestamp": "2023-08-19 21:14:14", "lastmod": "2024-01-14 19:29:59", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Leroy-Y-M", "name": { "family": "Leroy", "given": "Y." } }, { "id": "Ortiz-M", "name": { "family": "Ortiz", "given": "M." }, "orcid": "0000-0001-5877-4824" } ] }, "title": "Localization analysis under dynamic loading", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 1989 Institute of Physics. \n\nSupport from the Office of Naval Research under grant N00014-85-K-0720 is gratefully acknowledged.\n\nPublished - LeroyOrtiz1989a.pdf
", "abstract": "A finite element method proposed by Ortiz et al. (1987) is used to study shear band formation in rate dependent and rate independent pressure sensitive solids under dynamic loading. Under these conditions, shear bands are observed to propagate in an irregular fashion in time and space. In particular, the development of multiple shear bands appears to be a prevalent mechanism of deformation at sufficiently high impact velocities.", "date": "1989", "date_type": "published", "publisher": "IOP", "place_of_pub": "New York, NY", "pagerange": "257-265", "id_number": "CaltechAUTHORS:20180110-100539242", "isbn": "085498058X", "book_title": "Mechanical properties of Materials at high rates of strain, 1989", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180110-100539242", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-85-K-0720" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Harding-J", "name": { "family": "Harding", "given": "J." } } ] }, "primary_object": { "basename": "LeroyOrtiz1989a.pdf", "url": "https://authors.library.caltech.edu/records/wvc5y-a5d43/files/LeroyOrtiz1989a.pdf" }, "pub_year": "1989", "author_list": "Leroy, Y. and Ortiz, M." }, { "id": "https://authors.library.caltech.edu/records/6hzza-n0j78", "eprint_id": 79596, "eprint_status": "archive", "datestamp": "2023-08-22 06:10:31", "lastmod": "2024-01-13 23:26:33", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Broadwell-J-E", "name": { "family": "Broadwell", "given": "James E." } } ] }, "title": "A Model for Reactions in Turbulent Jets: Effects of Reynolds, Schmidt, and Damk\u00f6hler Numbers", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Reynolds Number; Shear Layer; Equivalence Ratio; Schmidt Number; Flame Length", "note": "\u00a9 1989 Springer-Verlag New York Inc. \n\nThis paper is extracted from a summary report on mixing and reactions in shear layers and jets that is in preparation in collaboration with Godfrey M. Mungal. His assistance as well as that of the author's GALCIT colleagues is gratefully acknowledged. The ideas of Roddam Narasimha and Anatol Roshko concerning the volume fraction in which dissipation occurs helped greatly to clarify the relationship between dissipation and scalar mixing. The author also thanks Werner Dahm and Manooch Koochesfahani for permission to use figures from their theses and for many instructive discussions of their work. We wish to acknowledge support for this work by the Air Force Office of Scientific Research under Contract No. F49602-79-C-0159 and Grant No. M'OSR-83-0213, the Office of Naval Research under Contract No. 00014-85-k-06116, and the Gas Research Institute under Grant No. 5083-260-0878.", "abstract": "Data from several recent experiments on mixing and chemical reactions in turbulent shear layers and jets is discussed in detail and used to formulate a picture of the path from the freestream to the molecularly mixed State. A model is proposed which incorporates the essential steps in this path and which appears to provide a framework for understanding the major effects of Reynolds, Schmidt, and Damk\u00f6hler numbers on the chemical reaction. A simplified version of the model reproduces the observed Reynolds number dependence of nitric oxide production in turbulent fuel jets.", "date": "1989", "date_type": "published", "publisher": "Springer", "place_of_pub": "New York, NY", "pagerange": "257-277", "id_number": "CaltechAUTHORS:20170731-111135558", "isbn": "978-0-387-96887-2", "book_title": "Turbulent Reactive Flows", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170731-111135558", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "F49602-79-C-0159" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "AFOSR-83-0213" }, { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-85-K-0646" }, { "agency": "Gas Research Institute", "grant_number": "5083-260-0878" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Borghi-R", "name": { "family": "Borghi", "given": "R." } }, { "id": "Murthy-S-N-B", "name": { "family": "Murthy", "given": "S. N. B." } } ] }, "doi": "10.1007/978-1-4613-9631-4_16", "pub_year": "1989", "author_list": "Broadwell, James E." }, { "id": "https://authors.library.caltech.edu/records/dt93k-wpc55", "eprint_id": 50869, "eprint_status": "archive", "datestamp": "2023-08-19 20:04:56", "lastmod": "2023-10-18 14:36:04", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Koochesfahani-M-M", "name": { "family": "Koochesfahani", "given": "Manoochehr M." } }, { "id": "Dimotakis-P-E", "name": { "family": "Dimotakis", "given": "Paul E." } } ] }, "title": "A Cancellation Experiment in a Forced Turbulent Shear Layer", "ispublished": "unpub", "full_text_status": "public", "note": "Copyright \u00a9 1988 by the American Institute of Aeronautics and Astronautics.\n\n88-3713-CP.\n\nWe would like to thank our colleagues in the\nAeronautics Department at Caltech for the many useful\ndiscussions and ideas. This work was initially supported\nunder the Caltech President's Fund Grant PF-126, in collaboration with Dr. Donald Collins of the Caltech Jet Propulsion Laboratory. Subsequent support continued under\nthe sponsorship of the Air Force Office of Scientific\nResearch Grant No. AFOSR-84-0120.\n\nPublished - a_cancellation_experiment.pdf
", "abstract": "Results are presented which demonstrate that it is possible to cancel, using feedback control techniques, the effects of an externally generated disturbance in a fully-developed turbulent two-dimensional shear layer.", "date": "1988", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "id_number": "CaltechAUTHORS:20141027-134908693", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141027-134908693", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech President's Fund", "grant_number": "PF-126" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "AFOSR-84-0120" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.1988-3713", "primary_object": { "basename": "a_cancellation_experiment.pdf", "url": "https://authors.library.caltech.edu/records/dt93k-wpc55/files/a_cancellation_experiment.pdf" }, "pub_year": "1988", "author_list": "Koochesfahani, Manoochehr M. and Dimotakis, Paul E." }, { "id": "https://authors.library.caltech.edu/records/n49cm-2jw50", "eprint_id": 79588, "eprint_status": "archive", "datestamp": "2023-08-19 20:09:24", "lastmod": "2023-10-26 16:57:57", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Sigurdson-L-W", "name": { "family": "Sigurdson", "given": "L. W." } }, { "id": "Roshko-A", "name": { "family": "Roshko", "given": "A." } } ] }, "title": "The Structure and Control of a Turbulent Reattaching Flow", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1988 Springer-Verlag Berlin Heidelberg. \n\nFinancial support for this research was provided by the Office of Naval Research. contract number N00014-76-C-0260. Travel funds were provided by the National Science Foundation.", "abstract": "An experimental study was made of the effect of a periodic velocity perturbation on the separation bubble downstream of the sharp-edged blunt face of a circular cylinder aligned coaxially with the free stream. Velocity fluctuations were produced with an acoustic driver located within the cylinder and a small circumferential gap located immediately downstream of the fixed separation line to allow communication with the external flow. The flow could be considerably modified when forced at frequencies lower than the initial Kelvin-Helmholtz frequencies of the free shear layer, and with associated vortex wavelengths comparable to the bubble height. Reattachment length, bubble height, pressure at separation, and average pressure on the face were all reduced. The effects on the large-scale structures were studied on flow photographs obtained by the smoke-wire technique. The forcing increased the entrainment near the leading edge. It was concluded that the final vortex of the shear layer before reattachment is an important element of the flow structure. There are two different instabilities involved, the Kelvin-Helmholtz instability of the free shear layer and the \"shedding\" type instability of the entire bubble. A method of frequency scaling is proposed which correlates data for a variety of bubbles and supports an analogy with Karman vortex shedding.", "date": "1988", "date_type": "published", "publisher": "Springer", "place_of_pub": "Berlin", "pagerange": "497-514", "id_number": "CaltechAUTHORS:20170731-100953029", "isbn": "978-3-642-83283-3", "book_title": "Turbulence Management and Relaminarisation", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170731-100953029", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-76-C-0260" }, { "agency": "NSF" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Liepmann-H-W", "name": { "family": "Liepmann", "given": "H. W." } }, { "id": "Narasimhan-R", "name": { "family": "Narasimhan", "given": "R." } } ] }, "doi": "10.1007/978-3-642-83281-9_34", "pub_year": "1988", "author_list": "Sigurdson, L. W. and Roshko, A." }, { "id": "https://authors.library.caltech.edu/records/cb3bx-20g31", "eprint_id": 50580, "eprint_status": "archive", "datestamp": "2023-08-19 20:04:42", "lastmod": "2023-10-17 23:57:01", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Frieler-C-E", "name": { "family": "Frieler", "given": "C. E." } }, { "id": "Dimotakis-P-E", "name": { "family": "Dimotakis", "given": "P. E." } } ] }, "title": "Mixing and Reaction at Low Heat Release in the Non-Homogeneous Shear Layer", "ispublished": "unpub", "full_text_status": "public", "note": "Copyright \u00a9 1988 by C. E. Frieler and P. E. Dimotakis. Published by the American Institute of Aeronautics and Astronautics, Inc. with permission.\n\nAIAA-88-3626.\n\nPublished - mixing_and_reaction.pdf
", "abstract": "The effects of freestream density ratio on the\nmixing and combustion in a high Reynolds number,\nsubsonic, gas-phase, non-buoyant, two-dimensional\nturbulent mixing layer, have been investigated.\nMeasurements of temperature rise (heat release)\nhave been made which enable us to examine the\neffect of freestream density ratio on several\naspects of the mixed fluid state within the\nturbulent combustion region. In experiments with\nvery high and very low stoichiometric mixture\nratios (\"flip\" experiments), the heat release from\nan exothermic reaction serves as a quantitative\nlabel for the lean reactant freestream fluid that\nbecomes molecularly mixed. Properly normalized,\nthe sum of the mean temperature rise profiles of\nthe two flip experiments represent the probability\nof fluid molecularly mixed at any composition. The\nmole fraction distribution and number density\nprofile of the mixed fluid can also be inferred\nfrom such measurements. Although the density ratio\nin these experiments was varied by a factor of\nthirty, profiles of these quantities show little\nvariation, with integrals varying by less than 10%.\nThis insensitivity differs from that of the\ncomposition of molecularly mixed fluid, which is\nvery sensitive to the density ratio. While the\nprofiles of composition exhibit some similarity of\nshape, the average composition of mixed fluid in\nthe layer varies from nearly 1:2 to over 2:l as the\ndensity ratio is increased. A comparison of data\nand available theory for this offset or average\ncomposition is discussed.", "date": "1988", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "id_number": "CaltechAUTHORS:20141020-153743550", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141020-153743550", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "primary_object": { "basename": "mixing_and_reaction.pdf", "url": "https://authors.library.caltech.edu/records/cb3bx-20g31/files/mixing_and_reaction.pdf" }, "pub_year": "1988", "author_list": "Frieler, C. E. and Dimotakis, P. E." }, { "id": "https://authors.library.caltech.edu/records/6g2b4-cgp46", "eprint_id": 79589, "eprint_status": "archive", "datestamp": "2023-08-19 20:09:32", "lastmod": "2023-10-26 16:58:02", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Arakeri-J-H", "name": { "family": "Arakeri", "given": "J. H." } }, { "id": "Coles-D-E", "name": { "family": "Coles", "given": "D. E." } } ] }, "title": "Measurements in a Synthetic Turbulent Boundary Layer", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1988 Springer-Verlag Berlin Heidelberg. \n\nThe research described in this paper was supported by the\nNational Science Foundation under Grant MEA-8315042.", "abstract": "Some measurements in a synthetic turbulent boundary layer (SBL) are reported. The main diagnostic tool is an X-wire probe. The celerity of the large eddies is determined to be 0.842 u\u221e. The mean properties of the SBL are reasonably close to those of a natural turbulent boundary layer. The large eddy in the SBL appears to be a pair of counter-rotating eddies in the stream direction, inclined at a shallow angle and occupying much of the boundary-layer thickness.", "date": "1988", "date_type": "published", "publisher": "Springer", "place_of_pub": "Berlin", "pagerange": "23-36", "id_number": "CaltechAUTHORS:20170731-101627746", "isbn": "978-3-642-83283-3", "book_title": "Turbulence Management and Relaminarisation", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170731-101627746", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "MEA-8315042" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Liepmann-H-W", "name": { "family": "Liepmann", "given": "H. W." } }, { "id": "Narasimhan-R", "name": { "family": "Narasimhan", "given": "R." } } ] }, "doi": "10.1007/978-3-642-83281-9_2", "pub_year": "1988", "author_list": "Arakeri, J. H. and Coles, D. E." }, { "id": "https://authors.library.caltech.edu/records/0hmk7-84a62", "eprint_id": 50584, "eprint_status": "archive", "datestamp": "2023-08-19 20:04:52", "lastmod": "2023-10-17 23:57:13", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Zhuang-M", "name": { "family": "Zhuang", "given": "Mei" } }, { "id": "Kubota-T", "name": { "family": "Kubota", "given": "Toshi" } }, { "id": "Dimotakis-P-E", "name": { "family": "Dimotakis", "given": "Paul E." } } ] }, "title": "On the instability of inviscid, compressible free shear layers", "ispublished": "unpub", "full_text_status": "public", "note": "Copyright \u00a9 1988 by Mei Zhuang. Published by the\nAmerican Institute of Aeronautics and\nAstronautics, Inc. with permission.\n\nAIAA-88-3538-CP.\n\nWe would like to thank Dr. Dimitri\nPapamoschou, Mr. Paul Miller and Mr. Cliff\nFrieler for their helpful discussions and\nassistance. This work was supported by the Air\nForce Office of Scientific Research Grants No.\n83-0213 and 88-0155.\n\nPublished - on_the_instability_of_inviscid.pdf
", "abstract": "The linear spatial instability of inviscid\ncompressible laminar mixing of two parallel\nstreams, comprised of the same gas, has been\ninvestigated with respect to two-dimensional wave\ndisturbances. The effects of the velocity ratio,\ntemperature ratio, and the temperature profile\nacross the shear layer have been examined. A\nnearly universal dependence of the normalized\nmaximum amplification rate on the convective Mach\nnumber is found, with the normalized maximum\namplification rate decreasing significantly with\nincreasing convective Mach number in the subsonic\nregion. These results are in accord with those of\nrecent growth rate experiments in compressible\nturbulent free shear layers and other similar\nrecent calculations.", "date": "1988", "date_type": "published", "publisher": "AIAA", "id_number": "CaltechAUTHORS:20141020-155658655", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141020-155658655", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "83-0213" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "88-0155" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.1988-3538", "primary_object": { "basename": "on_the_instability_of_inviscid.pdf", "url": "https://authors.library.caltech.edu/records/0hmk7-84a62/files/on_the_instability_of_inviscid.pdf" }, "pub_year": "1988", "author_list": "Zhuang, Mei; Kubota, Toshi; et el." }, { "id": "https://authors.library.caltech.edu/records/9kpmw-5xj30", "eprint_id": 41680, "eprint_status": "archive", "datestamp": "2023-08-19 20:03:24", "lastmod": "2024-01-13 06:04:34", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Gharib-M", "name": { "family": "Gharib", "given": "M." } }, { "id": "Willert-C", "name": { "family": "Willert", "given": "C." }, "orcid": "0000-0002-1668-0181" } ] }, "title": "Particle Tracing: Revisited", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1988 Springer-Verlag.\n\nAn initiation grant from the Engineering Foundation (GR Engng Fdn RI-A-86-7) has been\ninstrumental in the development of the automatic panicle tracing technique described in this paper.\nCurrently a grant from DARPA/ACMP is supporting us in efforts to add the three-dimensional and\nmultifield capability to the technique. Many colleagues and former students have helped us in bringing the\ntechnique to its present stage. We would like to thank Dr. Miguel Heman for helping with the initial\ndevelopment of the idea, Barry Dyne and Oran Thomas for helping in the development of software, Thomas\nPhillips and Chee Yap for different stages of hardware development and Dr. Kathie Stuber for her careful\nlaser doppler measurements.", "abstract": "Particle tracing is a simple technique used to infer global quantitative information regarding velocity\nand vorticity fields from flow images. In this paper, recent advances in solving major drawbacks associated\nwith conventional particle tracing are discussed. A quantitative automatic scheme which eliminates the\nphotographic step and is capable of constructing the velocity field directly from the experimental set up is\npresented.", "date": "1988", "date_type": "published", "publisher": "Springer-Verlag", "place_of_pub": "Berlin", "pagerange": "109-126", "id_number": "CaltechAUTHORS:20131004-101510360", "isbn": "9780387194837", "book_title": "Finite element analysis for engineering design", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131004-101510360", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Engineering Foundation", "grant_number": "RI-A-86-7" }, { "agency": "DARPA/ACMP" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Reddy-J-N", "name": { "family": "Reddy", "given": "J. N." } }, { "id": "Krishnamoorthy-C-S", "name": { "family": "Krishnamoorthy", "given": "C. S." } }, { "id": "Seetharamu-K-N", "name": { "family": "Seetharamu", "given": "K. N." } } ] }, "pub_year": "1988", "author_list": "Gharib, M. and Willert, C." }, { "id": "https://authors.library.caltech.edu/records/ssx1n-mjr33", "eprint_id": 50582, "eprint_status": "archive", "datestamp": "2023-08-19 20:04:47", "lastmod": "2023-10-17 23:57:06", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Dowling-D-R", "name": { "family": "Dowling", "given": "David R." } }, { "id": "Dimotakis-P-E", "name": { "family": "Dimotakis", "given": "Paul E." } } ] }, "title": "On Mixing and Structure of the Concentration Field of Turbulent Jets", "ispublished": "unpub", "full_text_status": "public", "note": "Copyright \u00a9 1988 by David R. Dowling. Published\nby the American Institute of Aeronautics and\nAstronautics Inc. with permission.\n\n88-3611-CP.\n\nThe authors wish to ac:knowledge Dr. Daniel\nB. Lang for his assistance in the design and\nfabrication of the whole data acquisition system.\nThis work was supported by the Gas Research\nInstitute grant #5083-260-0870 and the Air Force\nOffice of Scientific Research contract # 83-0213.\n\nPublished - on_mixing_and_structure.pdf
", "abstract": "This work is an investigation of the mixing\nof the nozzle fluid of a round turbulent jet with\nthe entrained reservoir fluid, using\nlaser-Rayleigh scattering methods. Our\nmeasurements, at a Reynolds number of 5000, cover\nthe axial range from 20 to 80 jet exit diameters\nand resolve the full range of temporal & spatial\nconcentration scales. The measured mean & rms\nvalues of the concentration, and the mean scalar\ndissipation rate, when estimated from the time\nderivative of concentration, are consistent with\njet similarity laws. Concentration fluctuation\npower spectra are found to be self-similar along\nrays emanating from the jet virtual origin. The\nprobability density functions for the\nconcentration, the time derivative of\nconcentration, and the square of the time\nderivative of concentration, are compiled and are\nalso self-similar along rays.", "date": "1988", "date_type": "published", "publisher": "AIAA", "id_number": "CaltechAUTHORS:20141020-154527512", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141020-154527512", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gas Research Institute", "grant_number": "5083-260-0878" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "83-0213" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.1988-3611", "primary_object": { "basename": "on_mixing_and_structure.pdf", "url": "https://authors.library.caltech.edu/records/ssx1n-mjr33/files/on_mixing_and_structure.pdf" }, "pub_year": "1988", "author_list": "Dowling, David R. and Dimotakis, Paul E." }, { "id": "https://authors.library.caltech.edu/records/vr22e-p5z58", "eprint_id": 50570, "eprint_status": "archive", "datestamp": "2023-08-19 19:07:05", "lastmod": "2023-10-17 23:56:23", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Dimotakis-P-E", "name": { "family": "Dimotakis", "given": "Paul E." } }, { "id": "Hall-J-L", "name": { "family": "Hall", "given": "Jeffery L." } } ] }, "title": "A Simple Model for Finite Chemical Kinetics Analysis of Supersonic Turbulent Shear Layer Combustion", "ispublished": "unpub", "full_text_status": "public", "note": "Copyright (1987) by J. L. Hall and P. E.\nDimotakis.\n\nAIAA-87-1879.\n\nWe would like to acknowledge the helpful\ndiscussions with Dr. G. Mungal. The work was\nsupported by AFOSR Grant No. 83-0213.\n\nPublished - a_simple_model_for_finite.pdf
", "abstract": "A simple flow/thermodynamic model is proposed\nto describe finite chemical kinetic rate combustion\nin a turbulent supersonic shear layer for the\npurposes of assessing Damk\u00f6hler number effects in\nsuch flows. Sample calculations and comparisons\nfor the H_2/NO/F_2 chemical system and the H_2/air\nsystem are described for a set of initial flow and\nthermodynamic conditions of the entrained\nreactants.", "date": "1987", "date_type": "published", "publisher": "American Institute of Aeronautics and Astronautics", "id_number": "CaltechAUTHORS:20141020-150416296", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141020-150416296", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "83-0213" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.1987-1879", "primary_object": { "basename": "a_simple_model_for_finite.pdf", "url": "https://authors.library.caltech.edu/records/vr22e-p5z58/files/a_simple_model_for_finite.pdf" }, "pub_year": "1987", "author_list": "Dimotakis, Paul E. and Hall, Jeffery L." }, { "id": "https://authors.library.caltech.edu/records/vea6k-35x13", "eprint_id": 21217, "eprint_status": "archive", "datestamp": "2023-08-19 18:00:30", "lastmod": "2024-01-13 00:07:31", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Culick-F-E-C", "name": { "family": "Culick", "given": "Fred E. C." } }, { "id": "Jex-H-R", "name": { "family": "Jex", "given": "Henry R." } } ] }, "title": "Aerodynamics, Stability and Control of the 1903 Wright Flyer", "ispublished": "unpub", "full_text_status": "public", "keywords": "Wright Flyer Project", "note": "September 20, 1984. Systems Technology, Inc., Paper No. 359.\nWe thank Mrs. C. Yehle of Caltech for typing the\nmanuscript through many drafts, and Mr. C. Reaber for the great care with which he prepared the figures.\n\nTo be published in \"Proceedings of the Symposium on the 80th Anniversary\nof the Wright Brothers First Flight\", Smithsonian Institution;\nDec. 16, 1983. Copyright reserved.\n\nThis draft version is for limited review and distribution. Permission\nto republish any portion must be obtained from the Smithsonian\n(Mr. Wolko); however the right to reference this paper in technical\nreports is hereby granted.\n\nAccepted Version - CULaiaawfp84.pdf
", "abstract": "The Los Angeles Chapter of the American Institute of Aero and\nAstronautics is building two replicas of the 1903 Wright Flyer airplane;\none to wind-tunnel test and display, and a modified one to fly. As part\nof this project the aerodynamic characteristics of the Flyer are being\nanalyzed by modern wind-tunnel and analytical techniques. Tnis paper\ndescribes the Wright Flyer Project, and compares key results from\nsmall-scale wind-tunnel tests and from vortex-lattice computations for\nthis multi-biplane canard configuration. Analyses of the stability and\ncontrol properties are summarized and their implications for closed-loop\ncontrol by a pilot are derived using quasilinear pilot-vehicle analysis\nand illustrated by simulation time histories.\nIt is concluded that, although the Wrights were very knowledgeable\nand ingenious with respect to aircraft controls and their interactions\n(e.g., the good effects of their wing-warp-to-rudder linkage are\nvalidated), they were largely ignorant of dynamic stability\nconsiderations. The paper shows that the 1903 Flyer was readily\ncontrollable about all axes but was intrinsically unstable in pitch and\nroll, and it could barely be stabilized by a skilled pilot.", "date": "1985-09-20", "date_type": "published", "publisher": "National Air and Space Museum, Smithsonian Institution", "id_number": "CaltechAUTHORS:20101207-140100221", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20101207-140100221", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "359", "name": "Systems Technology, Inc. Paper" } ] }, "local_group": { "items": [ { "id": "Guggenheim-Jet-Propulsion-Center" }, { "id": "GALCIT" } ] }, "primary_object": { "basename": "CULaiaawfp84.pdf", "url": "https://authors.library.caltech.edu/records/vea6k-35x13/files/CULaiaawfp84.pdf" }, "pub_year": "1985", "author_list": "Culick, Fred E. C. and Jex, Henry R." }, { "id": "https://authors.library.caltech.edu/records/15fye-krv08", "eprint_id": 79594, "eprint_status": "archive", "datestamp": "2023-08-19 17:31:27", "lastmod": "2023-10-26 16:58:14", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Dahm-W-J-A", "name": { "family": "Dahm", "given": "W. A." } }, { "id": "Dimotakis-P-E", "name": { "family": "Dimotakis", "given": "P. E." } } ] }, "title": "Measurements of Entrainment and Mixing in Turbulent Jets", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 1984 Werner J.A. Dahm.", "abstract": "An experimental investigation of entrainment and mixing in the self-similar far field of an axisymmetric free turbulent jet in water is presented. Length and time scales for the flame length fluctuations of reacting jets are shown to be approximately equal to the local characteristic large scale length and time of the flow. It is also shown that instantaneous radial profiles of concentration across the jet do not resemble the mean concentration profile, indicating that the mean profile is a poor representation of the mixed fluid states within the jet. These instantaneous profiles also show that unmixed ambient fluid is transported throughout the entire extent of the jet, and that the mixed fluid composition within the jet can be fairly uniform in regions extending across a large part of the local jet diameter. Lastly, the amount of unmixed ambient fluid on the jet centerline is found to vary roughly periodically with a period approximately equal to the local characteristic large scale time of the flow. These results suggest that large scale transport mechanisms, displaying a characteristic organization, play an important role in entrainment and mixing in the far filed of turbulent jets.", "date": "1985-01", "date_type": "published", "id_number": "CaltechAUTHORS:20170731-105835407", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170731-105835407", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "doi": "10.2514/6.1985-56", "pub_year": "1985", "author_list": "Dahm, W. A. and Dimotakis, P. E." }, { "id": "https://authors.library.caltech.edu/records/jh1qt-x0836", "eprint_id": 105960, "eprint_status": "archive", "datestamp": "2023-08-22 02:55:26", "lastmod": "2023-10-20 22:54:58", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Sturtevant-B", "name": { "family": "Sturtevant", "given": "B." } }, { "id": "Shepherd-J-E", "name": { "family": "Shepherd", "given": "J. E." }, "orcid": "0000-0003-3181-9310" } ] }, "title": "Evaporative instability at the superheat limit", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Mass Flux; Vapor Bubble; Bubble Growth; Laminar Flame; Rapid Evaporation", "note": "\u00a9 Martinus Nijhoff Publishers, The Hague 1982. \n\nThis research was supported by the United States Department of Energy, Division of Chemical Sciences, under Project Agreement DE-AT03-80ER10634.", "abstract": "The explosive vaporization of a single bubble inside a droplet of butane heated to the limit of superheat has been investigated experimentally using short-exposure photographs and fast-response pressure measurements. An interfacial instability driven by rapid evaporation has been observed on the surface of the bubbles. It is proposed that the Landau mechanism of instability, originally described in connection with the instability of laminar flames, also applies to rapid evaporation at the superheat limit. Calculations suggest that other technically important fluids may be even more unstable when boiling at the superheat limit. The rate of evaporation after the onset of instability is estimated from the experimental measurements to be two orders of magnitude greater than would be predicted by conventional bubble-growth theories that do not account for the effects of instability. An estimate of the mean density within the bubbles during the evaporative stage indicates that it is nearly equal to the critical density of butane.", "date": "1982", "date_type": "published", "publisher": "Springer Netherlands", "place_of_pub": "Dordrecht", "pagerange": "85-97", "id_number": "CaltechAUTHORS:20201009-102843920", "isbn": "9789400975347", "book_title": "Mechanics and Physics of Bubbles in Liquids", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201009-102843920", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Department of Energy (DOE)", "grant_number": "DE-AT03-80ER10634" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "van-Wijngaarden-L", "name": { "family": "van Wijngaarden", "given": "L." } } ] }, "doi": "10.1007/978-94-009-7532-3_8", "pub_year": "1982", "author_list": "Sturtevant, B. and Shepherd, J. E." }, { "id": "https://authors.library.caltech.edu/records/gfbrn-9aj56", "eprint_id": 105859, "eprint_status": "archive", "datestamp": "2023-08-19 13:48:10", "lastmod": "2024-01-15 18:12:11", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Roshko-A", "name": { "family": "Roshko", "given": "A." } } ] }, "title": "The plane mixing layer flow visualization results and three dimensional effects", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 Springer-Verlag 1981. \n\nI am indebted to L. Bernal, R.E. Breidenthal, J.E. Broadwell, G.L. Brown and P.E. Dimotakis for discussions of the problems explored here and for use of material in the figures. The research work on which this paper is based was made possible by the financial support of the Office of Naval Research, through Project SQUID and through its Fluid Dynamics Program, and of the Air Force Office of Scientific Research through the Air Force Weapons Laboratory.", "abstract": "The turbulent mixing layer between two streams of different velocities continues to play a central role in research aimed at improved understanding of turbulent shear flows in general, At present, not all researchers are in agreement as to what various experiments imply about the structure of mixing layers at high Reynolds number. The views which are held differ on the question as to how and to what extent three dimensionality develops in these flows and whether the Characteristic spanwise organized large vortex structures (rollers) continue to be a dominant feature. The traditional view, as extended to the contemporary scene, is that ultimately (i.e., sufficiently far downstream or at sufficiently high Reynolds number) the flow will be completely disorganized. The view put forward by \"eddy chasers\" is that such vortex structures are primary elements, characteristic of the underlying mean vorticity field, which is particularly simple for the mixing layer, and that, as long as the velocity difference is maintained, there is a mechanism to regenerate these primary structures by what, for convenience, may be called a Kelvin-Helmholtz instability, The heart of the controversy then is whether, or to what extent, secondary and higher instabilities will ultimately break down, completely disorganize or prevent formation of organized primary structures. In a plane mixing layer, the primary structures would, ideally, be two dimensional, containing the basic single component of vorticity while secondary and higher modes of instability would introduce three dimensionality and the other two components of vorticity into the flow. An interesting question follows: to what extent do such secondary instabilities change the properties (e.g., the growth rate; the Reynolds stress) that the mixing layer would have in ideal two dimensional development? In this paper we examine several aspects of this question and discuss some recent relevant experiments.", "date": "1981", "date_type": "published", "publisher": "Springer Berlin Heidelberg", "place_of_pub": "Berlin, Heidelberg", "pagerange": "208-217", "id_number": "CaltechAUTHORS:20201007-081705336", "isbn": "9783540102892", "book_title": "The Role of Coherent Structures in Modelling Turbulence and Mixing", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201007-081705336", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)" }, { "agency": "Air Force Office of Scientific Research (AFOSR)" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Jimenez-J", "name": { "family": "Jimenez", "given": "J." } } ] }, "doi": "10.1007/3-540-10289-2_27", "pub_year": "1981", "author_list": "Roshko, A." }, { "id": "https://authors.library.caltech.edu/records/wd164-yjc15", "eprint_id": 79590, "eprint_status": "archive", "datestamp": "2023-08-19 11:07:58", "lastmod": "2023-10-26 16:58:04", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Roshko-A", "name": { "family": "Roshko", "given": "A." } }, { "id": "Koenig-K", "name": { "family": "Koenig", "given": "K." } } ] }, "title": "Interaction Effects on the Drag of Bluff Bodies in Tandem", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 1978 Plenum Press, New York.", "abstract": "The objective of this study is to obtain better understanding of the flow over two tandemly positioned bluff bodies in close enough proximity to strongly interact with each other. This interaction is often beneficial in that the drag of the overall system is reduced. Prototypes for this problem come from tractor-trailer and cab-van combinations, and from various add-on devices designed to reduce their drag.\nThe primary object of the present investigation is an axisymmetric configuration which seems to have first been studied by Saunders (1966). A disc of diameter d_1 is coaxially placed in front of a flat-faced cylinder of diameter d_2. For a given ratio d1/d2, there is a value of gap ratio, g*/d_2, for which the drag of the forebody system is a minimum. In the most optimum configuration, d_1/d_2 = 0.75, g*/d_2 = 0.375, and the corresponding forebody drag coefficient is 0.02, a remarkable reduction from the value of 0.75 for the cylinder alone. For each value of d_1/d_2, the minimum drag configuration, g*/d_2, appears to correspond to a minimum dissipation condition in which the separation stream surface just matches (joins tangentially onto) the rearbody. Support for this idea is furnished by comparison with some results derived from free-streamline theory and from flow visualization experiments. However, when g*/d_2 exceeds a critical value of about 0.5, the value of C_(Dmin) is almost an order of magnitude higher than for subcritical optimum gap ratios. The increase seems to be connected with the onset of cavity oscillations.\nFor non-axisymmetric geometry (square cross-sections) the separation surface cannot exactly match the rearbody and the subcritical minimum values of drag are higher than for circular cross-sections.", "date": "1978", "date_type": "published", "publisher": "Springer", "place_of_pub": "Boston, MA", "pagerange": "253-286", "id_number": "CaltechAUTHORS:20170731-102517069", "isbn": "978-1-4684-8436-6", "book_title": "Aerodynamic Drag Mechanisms of Bluff Bodies and Road Vehicles", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170731-102517069", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Sovran-G", "name": { "family": "Sovran", "given": "Gino" } }, { "id": "Morel-T", "name": { "family": "Morel", "given": "Thomas" } }, { "id": "Mason-T-J-Jr", "name": { "family": "Mason", "given": "William T., Jr." } } ] }, "doi": "10.1007/978-1-4684-8434-2_10", "pub_year": "1978", "author_list": "Roshko, A. and Koenig, K." }, { "id": "https://authors.library.caltech.edu/records/0x006-rj374", "eprint_id": 79691, "eprint_status": "archive", "datestamp": "2023-08-22 01:19:17", "lastmod": "2024-01-13 23:27:55", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hornung-H-G", "name": { "family": "Hornung", "given": "Hans" }, "orcid": "0000-0002-4903-8419" }, { "id": "Killen-P", "name": { "family": "Killen", "given": "Peter" } } ] }, "title": "Laboratory study of a stationary oblique plunging breaker for surfboard testing", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Wave Height; Free Stream; Breaking Wave; Ocean Wave; Wave Shape", "note": "\u00a9 1977 Springer-Verlag. \n\nWe would like to thank Dr. Keith Crook of the Department of Geology, ANU for making the flume available for the experiments, and Mr. K.C. Smith for his excellent efforts in the extensive photographic work involved in the project. The photograph of figure 3a was kindly made available by the magazine Surfing World.", "abstract": "Consider a water wave which is obliquely incident on a sloping beach. An observer looking along the wave front from the beach sees the portion of the wave closest to him to be already broken while that far from him is still in deep water and unbroken. In the transition region, the waveface reaches its maximum slope and this is therefore the part most suitable for the surfboard rider, who uses the waveface much like a skier uses a mountain. Because the wave breaks when the water depth reaches a particular value, the path of the break point, and therefore of the surfboard rider, is along the sea bottom contour. His average velocity is that of the intersection of the bottom contour and the wave. He therefore moves faster than the propagation speed of the wave even if his velocity is constant.", "date": "1977", "date_type": "published", "publisher": "Springer", "place_of_pub": "Berlin", "pagerange": "121-128", "id_number": "CaltechAUTHORS:20170801-130806604", "isbn": "978-3-540-08253-8", "book_title": "Waves on Water of Variable Depth", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170801-130806604", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "contributors": { "items": [ { "id": "Provis-D-G", "name": { "family": "Provis", "given": "D. G." } }, { "id": "Radok-R", "name": { "family": "Radok", "given": "R." } } ] }, "doi": "10.1007/3540082530_143", "pub_year": "1977", "author_list": "Hornung, Hans and Killen, Peter" }, { "id": "https://authors.library.caltech.edu/records/vr9ed-ex370", "eprint_id": 79690, "eprint_status": "archive", "datestamp": "2023-08-19 05:57:51", "lastmod": "2024-01-13 23:27:54", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Coles-D-E", "name": { "family": "Coles", "given": "D." } }, { "id": "Liepmann-H-W", "name": { "family": "Liepmann", "given": "H. W." } }, { "id": "Roshko-A", "name": { "family": "Roshko", "given": "A." } }, { "id": "Sturtevant-B", "name": { "family": "Sturtevant", "given": "B." } } ] }, "title": "Shock Tubes in Rarefied Gas Flow Research", "ispublished": "unpub", "full_text_status": "public", "note": "Published - Shock_Tubes_in_Rarefied_Gas_Flow_Research.pdf
", "abstract": "In any real fluid motion there exists regions in space-time\nin which the fluid is far from thermodynamic equilibrium.\nThe relative extent of these non-equilibrium regions is\ndetermined by the ratio of the molecular relaxation times and the corresponding length scales to the macroscopic time and space scales appropriate to the flow. Gas flow within such non-equilibrium regions is properly called \"rarefied\". In recent years the shock tube has become a rather efficient tool in the investigations of rarefied gas flows and I intend to illustrate progress in this use through a discussion of some very recent and typical investigations of the GALCIT group carried out under NASA sponsorship.", "date": "1968", "date_type": "published", "publisher": "Ernst-Mach-Institut", "id_number": "CaltechAUTHORS:20170801-130148469", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170801-130148469", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "GALCIT" } ] }, "primary_object": { "basename": "Shock_Tubes_in_Rarefied_Gas_Flow_Research.pdf", "url": "https://authors.library.caltech.edu/records/vr9ed-ex370/files/Shock_Tubes_in_Rarefied_Gas_Flow_Research.pdf" }, "pub_year": "1968", "author_list": "Coles, D.; Liepmann, H. W.; et el." }, { "id": "https://authors.library.caltech.edu/records/a2z2w-q7y23", "eprint_id": 62430, "eprint_status": "archive", "datestamp": "2023-08-19 05:15:25", "lastmod": "2023-10-25 17:09:09", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Williams-M-L", "name": { "family": "Williams", "given": "M. L." } }, { "id": "Knauss-W-G", "name": { "family": "Knauss", "given": "W. G." } }, { "id": "Wagner-F-R", "name": { "family": "Wagner", "given": "F. R." } } ] }, "title": "Fatigue Failure in Linearly Viscoelastic Masterials", "ispublished": "unpub", "full_text_status": "public", "note": "CPIA Publication 119, Vol. I.\n\nA substantial portion of the work reported herein was supported by the National Aeronautics and Space Administration under Research Grant No. NsG 172-60 and Contract No. NGR-45-003-029.\n\nPublished - fatigue_failuer.pdf
", "abstract": "The thermodynamic approach to the fracture of linearly viscoelastic materials presented earlier is extended to include fatigue. The theoretical analysis of the growth of an internal spherical flaw due to a uniformly distributed,\noscillatory input of displacement in the radial direction predicts a growth-rest type of flaw growth which depends upon the properties of the media and the loading frequency. Comparison of these results with experimental\ncrack growth data for a pre-cracked sheet specimen subjected to an oscillatory displacement input discloses a qualitative similarity in behavior. It is, therefore, believed that the analytical model employed is representative of real flaw behavior and that its study can reveal the main features of macroscopic flaw-growth.", "date": "1966", "date_type": "published", "publisher": "Chemical Propulsion Information Agency", "id_number": "CaltechAUTHORS:20151125-113158676", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151125-113158676", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA", "grant_number": "NsG 172-60" }, { "agency": "NASA", "grant_number": "NGR-45-003-029" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "primary_object": { "basename": "fatigue_failuer.pdf", "url": "https://authors.library.caltech.edu/records/a2z2w-q7y23/files/fatigue_failuer.pdf" }, "pub_year": "1966", "author_list": "Williams, M. L.; Knauss, W. G.; et el." }, { "id": "https://authors.library.caltech.edu/records/35ez5-7fe83", "eprint_id": 62431, "eprint_status": "archive", "datestamp": "2023-08-19 05:15:29", "lastmod": "2023-10-25 17:09:11", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Knauss-W-G", "name": { "family": "Knauss", "given": "W. G." } } ] }, "title": "Time-Dependent Failure of Viscoelastic Materials Under Cyclic Loads", "ispublished": "unpub", "full_text_status": "public", "note": "CPIA Publication 119, Vol. I.\n\nThis work was supported by the National Aeronautics and Space\nAdministration through Research Grant NsG-172-60.\n\nPublished - time-dependent_failure.pdf
", "abstract": "The problem of failure in viscoelastic materials under cyclic strain histories is treated theoretically by using a fracture model based on the theory of rate processes. Failure times in constant, uniaxial strain tests are compared with failure times encountered\nin sinusoidal strain histories. The dependence of the latter on the mean strain, the size of the strain variation and its frequency is illustrated. It is pointed out that for certain conditions a difference in the failure times in constant or cyclic strain histories may be\nmasked entirely by statistical data scatter. Finally the failure of solid propellant fuels under cyclic loading is discussed in the light of the results derived for a continuum rubber.", "date": "1966", "date_type": "published", "publisher": "Chemical Propulsion Information Agency", "id_number": "CaltechAUTHORS:20151125-113438967", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151125-113438967", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA", "grant_number": "NsG-172-60" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "primary_object": { "basename": "time-dependent_failure.pdf", "url": "https://authors.library.caltech.edu/records/35ez5-7fe83/files/time-dependent_failure.pdf" }, "pub_year": "1966", "author_list": "Knauss, W. G." }, { "id": "https://authors.library.caltech.edu/records/2g0fj-g2k30", "eprint_id": 18349, "eprint_status": "archive", "datestamp": "2023-08-19 04:30:48", "lastmod": "2024-01-12 23:40:04", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Knauss-W-G", "name": { "family": "Knauss", "given": "Wolfgang G." } } ] }, "title": "On the mechanical properties of an H-C rubber", "ispublished": "unpub", "full_text_status": "public", "note": "This investigation was made possible in part by the National Aeronautics and Space Administration Research Grant No. NsG 172-60, GALCIT 120. Thanks are due to Mr. John Clauser and Mr. Jon Kelly of the California Institute of Technology for conducting the dynamic shear and constant strain rate tests and to Mr. Bill Moser of the Jet Propulsion Laboratory for his supervision of the dynamic compliance measurements. Special gratitude is due to Dr. Robert Landel of the Jet Propulsion Laboratory for making his test equipment so readily available, and for his personal interest and help in data reduction. It is hoped that further analysis of these material properties will be carried out with his cooperation. The cooperation of Mr. G. H. Lindsey during the revision is gratefully acknowledged. \n\nThe material was obtained from the Thiokol Chemical Corporation, Huntsville, Alabama, through the courtesy of Drs. T. Neely and R. B. Kruse. The data on filled H-C rubber has been taken from reference 1.\n\nPublished - 319575.pdf
", "abstract": "The material properties of H-C binder including dynamic shear compliance, relaxation modulus, creep compliance, ultimate stress and ultimate strain are reported. Further useful information in the form of Modified Power Law and Prony Series curve fits are included as well as a master curve of reduced stress vs. strain. \n\nAll tests are performed using standard procedures; however some inconsistency in material properties has been found. It was further determined that the time-temperature shift principle is not directly applicable in its simplest form; however, upon postulating two molecular mechanisms responsible for gross deformations it is found that each one can be associated with a different characteristic glass transition temperature such that, e.g. the dynamic compliance J(w) is the sum of two compliances J_\u03b1 and J_\u03b3 \n\nJ(w,t) = J_\u03b1(w, T^\u03b1_glass) + J_\u03b3(w, T^\u03b3_glass) \n\nwhich individually follow the time temperature superposition principle.", "date": "1963-11", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20100519-091001010", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100519-091001010", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA", "grant_number": "NsG 172-60, GALCIT 120" } ] }, "local_group": { "items": [ { "id": "GALCIT" } ] }, "primary_object": { "basename": "319575.pdf", "url": "https://authors.library.caltech.edu/records/2g0fj-g2k30/files/319575.pdf" }, "pub_year": "1963", "author_list": "Knauss, Wolfgang G." } ]