Download or read book Experimental and Numerical Examination of a Hall Thruster Plume Preprint written by and published by . This book was released on 2007 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: The plume of a Busek BHT-200 xenon Hall thruster has been characterized through measurements from various plasma electrostatic probes. Ion current flux, plasma potential, plasma density, and electron temperatures were measured from the near-field plume to 60 cm downstream of the exit plane. These experimentally derived measurements were compared to numerical simulations run with the plasma plume code DRACO. A major goal of this study was to determine the fidelity of the DRACO numerical simulation. The effect of background pressure on the thruster plume was also examined using ion current flux measurements at higher than nominal pressure.
Download or read book Experimental and Theoretical Characterization of a Hall Thruster Plume written by Yassir Azziz and published by . This book was released on 2007 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Cont.) However, comparison of plume simulation and experimental results at a non-zero background pressure showed deficiencies in the collision model of the plume simulation. An analytical expression for current density obtained using a elf-similar plume model was compared to extrapolated current density at zero pressure and showed good agreement. In addition, an analytical model derived for current density of source ion collisions with neutrals was consistent with experimental measurements and confirms the deficiencies in the simulation's collision model. In summary, experimental, numerical and analytical results indicate that the method of determining in-orbit plume divergence from laboratory measurements is valid and can be used to integrate Hall thrusters with the spacecraft.
Download or read book An Experimental and Numerical Investigation of a Developing Buoyant Plume written by Douglas L. Reeder and published by . This book was released on 1992 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Faraday Probe Analysis Part 2 Evaluation of Facility Effects on Ion Migration in a Hall Thruster Plume Preprint written by and published by . This book was released on 2010 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: A nested Faraday probe was designed and fabricated to assess facility effects in a systematic study of ion migration in a Hall thruster plume. Current density distributions were studied at 8, 12, 16, and 20 thruster diameters downstream of the Hall thruster exit plane with four probe configurations at background pressures of 3x10-6, 1x10-5, and 3x10-5 torr. Several correction factors are applied to account for the effective probe collection area and systematic measurement error associated with measuring an annular device as an axisymmetric point source. These corrections enable the investigation of facility effects on beam expansion and ion migration in the plume. The effects of background facility neutrals are isolated, which enables precise and accurate estimate of thruster ion beam current and plume divergence. A set of guidelines are recommended for Faraday probe design, experimental approach, and data analysis of results that are aimed at minimizing measurement error of far-field Faraday probe measurements. These guidelines are shown to reduce the calculated ion beam current by 10-20% compared to conventional analysis techniques and to reduce measurement uncertainty to approximately +/-3%. The reductions in measurement uncertainty and the increased capability to approximate the on-orbit plume expansion from ground-based measurements are a significant improvement for comparisons with numerical simulations and investigations of Hall thruster performance.
Download or read book Experimental Verification of a PIC DSMC Model for Hall Thruster Plumes written by David Y. Oh and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental and Numerical Investigation of Low density Jet Plume written by 吳宗信 (機械工程) and published by . This book was released on 2003 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Investigation of Ion Thruster Plume Backflow written by N. A. Gatsonis and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modelling of N2 Thruster Plumes Based on Experiments in STG written by and published by . This book was released on 2000 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the DLR- high vacuum plume test facility STG experiments have been performed with the aim to validate the available plume flow model. For this purpose fully expanding simulated plumes with N2 as test gas have been chosen as simplest case (no chemical reactions, constant ratio of specific heats). The essential parameter to be varied was the nozzle flow Reynolds number, the quantities to be measured were the Pitot pressure at the nozzle exit and the molecule number flux in the plume. It turned out that a new model had to be written taking into account in a more appropriate way the development of the boundary layer in the nozzle and the initial plume spreading. The result is a code which describes the plume flow in satisfying agreement with the experimental data.
Download or read book Plasma Simulations by Example written by Lubos Brieda and published by CRC Press. This book was released on 2019-12-13 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of plasmas is crucial in improving our understanding of the universe, and they are being increasingly utilised in key technologies such as spacecraft thrusters, plasma medicine, and fusion energy. Providing readers with an easy to follow set of examples that clearly illustrate how simulation codes are written, this book guides readers through how to develop C++ computer codes for simulating plasmas primarily with the kinetic Particle in Cell (PIC) method. This text will be invaluable to advanced undergraduates and graduate students in physics and engineering looking to learn how to put the theory to the test. Features: Provides a step-by-step introduction to plasma simulations with easy to follow examples Discusses the electrostatic and electromagnetic Particle in Cell (PIC) method on structured and unstructured meshes, magnetohydrodynamics (MHD), and Vlasov solvers Covered topics include Direct Simulation Monte Carlo (DSMC) collisions, surface interactions, axisymmetry, and parallelization strategies. Lubos Brieda has over 15 years of experience developing plasma and gas simulation codes for electric propulsion, contamination transport, and plasma-surface interactions. As part of his master’s research work, he developed a 3D ES-PIC electric propulsion plume code, Draco, which is to this date utilized by government labs and private aerospace firms to study plasma thruster plumes. His Ph.D, obtained in 2012 from George Washington University, USA, focused on a multi-scale model for Hall thrusters utilizing fluid-kinetic hybrid PIC codes. He has since then been involved in numerous projects involving development and the use of plasma simulation tools. Since 2014 he has been teaching online courses on plasma simulations through his website: particleincell.com.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 716 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Performance Evaluation of the SPT 140 written by and published by . This book was released on 1997 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fundamentals of Electric Propulsion written by Dan M. Goebel and published by John Wiley & Sons. This book was released on 2008-12-22 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: Throughout most of the twentieth century, electric propulsion was considered the technology of the future. Now, the future has arrived. This important new book explains the fundamentals of electric propulsion for spacecraft and describes in detail the physics and characteristics of the two major electric thrusters in use today, ion and Hall thrusters. The authors provide an introduction to plasma physics in order to allow readers to understand the models and derivations used in determining electric thruster performance. They then go on to present detailed explanations of: Thruster principles Ion thruster plasma generators and accelerator grids Hollow cathodes Hall thrusters Ion and Hall thruster plumes Flight ion and Hall thrusters Based largely on research and development performed at the Jet Propulsion Laboratory (JPL) and complemented with scores of tables, figures, homework problems, and references, Fundamentals of Electric Propulsion: Ion and Hall Thrusters is an indispensable textbook for advanced undergraduate and graduate students who are preparing to enter the aerospace industry. It also serves as an equally valuable resource for professional engineers already at work in the field.
Download or read book Rocket and Spacecraft Propulsion written by Martin J. L. Turner and published by Springer Science & Business Media. This book was released on 2006-08-29 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: The revised edition of this practical, hands-on book discusses the launch vehicles in use today throughout the world, and includes the latest details on advanced systems being developed, such as electric and nuclear propulsion. The author covers the fundamentals, from the basic principles of rocket propulsion and vehicle dynamics through the theory and practice of liquid and solid propellant motors, to new and future developments. He provides a serious exposition of the principles and practice of rocket propulsion, from the point of view of the user who is not an engineering specialist.
Download or read book Air Pollution Abstracts written by and published by . This book was released on 1972 with total page 606 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fundamentals of Plasma Physics written by J. A. Bittencourt and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 700 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fundamentals of Plasma Physics is a general introduction designed to present a comprehensive, logical and unified treatment of the fundamentals of plasma physics based on statistical kinetic theory, with applications to a variety of important plasma phenomena. Its clarity and completeness makes the text suitable for self-learning and for self-paced courses. Throughout the text the emphasis is on clarity, rather than formality, the various derivations are explained in detail and, wherever possible, the physical interpretations are emphasized. The mathematical treatment is set out in great detail, carrying out the steps which are usually left to the reader. The problems form an integral part of the text and most of them were designed in such a way as to provide a guideline, stating intermediate steps with answers.
Download or read book Micro Newton Thruster Development written by Franz Georg Hey and published by Springer. This book was released on 2018-03-01 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: Franz Georg Hey summarises the development and testing of a micro-Newton thrust balance, as well as the downscaling of a High Efficiency Multistage Plasma Thruster to micro-Newton thrust levels. The balance is tailored to fully characterise thruster candidates for the space based gravitational wave detector LISA. Thus, thrust noise measurements in sub-micro-Newton regime can be performed in the overall LISA bandwidth. The downscaled thruster can be operated down to serval tens of micro-Newton with a comparably high specific impulse. About the Author Franz Georg Hey works as mechanical, thermal, propulsion architect and technical lead of the micro‐Newton propulsion laboratory of Europe’s leading air and spacecraft manufacturer. The author is participating on major programmes for future satellite and electric propulsion development. The author’s research is performed in close collaboration with the Dresden University of Technology, the University of Bremen and the DLR Bremen.
Download or read book Laser Spectroscopy written by Wolfgang Demtröder and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 710 pages. Available in PDF, EPUB and Kindle. Book excerpt: The impact of lasers on spectroscopy can hardly be overestimated. Lasers re present intense light sources with spectral energy densities which may exceed those of i ncoheren t sources by severa 1 orders of magnitude. Furthermore be cause of their extremely small bandwidth, single-mode lasers allow a spectral resolution which far exceeds that of conventional spectrometers. Many experi ments which could not be done before the application of lasers because of lack of intensity or insufficient resol ution are readily performed wi th lasers. Now several thousands of laser lines are known which span the whole spec tral range from the vacuum-ultraviolet to the far-infrared region. Of parti cular interest are the continuously tunable lasers which may in many cases replace wavelength-selecting elements, such as spectrometers or interferome ters. In combination with optical frequency mixing, techniques such conti nuously tunable monochromatic coherent light sources are available at nearly any desired wavelength above 100 nm.
