Download or read book Basic Research in Electric Propulsion Part I Pulsed Plasma Thruster Propellant Efficiency and Contamination Part II Arcjet Remote Plume Measurement and Hydrogen Density written by and published by . This book was released on 2002 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pulsed Plasma Thrusters (PPT) have been the major technology under investigation for the Small Satellite Electric Propulsion Thruster Research program. Arcjet technology is also under investigation with Electric Propulsion Space Experiment Optical Signature experiments underway and Multiphoton Laser Induced Fluorescence Measurements of Ground State Atomic Hydrogen have been performed in an arcjet plume. At present PPTs are being tested in the laboratory environment with investigations under way to determine exact inefficiency mechanisms that can be corrected. This work has already identified previously unknown physical behavior in the PPT. The Electric Propulsion Space Experiment is a flight demonstration of a 30 kW ammonia arcjet propulsion system. Optical measurements of the arcjet plume were performed using on-board optical equipment ground observatories and other space platforms. Low power arcjet technology provided definitive work on atomic species plume concentrations in low power hydrogen arcjet plumes. This work applied a flame diagnostic Multiphoton Laser Induced Fluorescence to the excited-state plasma environment to investigate concentration levels of atomic ground-state hydrogen.
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 Liquid Pulsed Plasma Thruster Plasma Plume Investigation and MR SAT Cold Gas Propulsion System Performance Analysis written by Jeremiah Daniel Hanna and published by . This book was released on 2017 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The plasma plume produced by a liquid pulsed plasma thruster is investigated using a Langmuir triple probe and a nude Faraday probe. The Langmuir triple probe failed to produce results which are suspected caused by the presence of ionic liquid in the plume resulting in shorting of the probe. The nude Faraday probe is able to record the ion current density which revealed a high level of inconsistency in the plasma plume. Ion current density recorded by the nude Faraday probe had a relative standard deviation of upwards of 100% of the mean value. Controlling the amount of propellant used during each pulse was extremely difficult. Investigating the plasma plume with more complex probes was not done due to the inconsistency measured by the nude Faraday probe and the expulsion of ionic liquid from the thruster which is highly corrosive to metals. Examining the historical thrust test data performed by the Missouri Satellite Research Team, a revised model with new assumptions was created and resulted in an improvement in accuracy to within 4.5%. The cold gas propulsion system developed over the years had undergone testing which resulted in measured thrust half of what was predicted. Developing a thrust prediction scheme that incorporates the effects of the solenoid control valve decreases the error to between 1-3% depending on temperature considerations. This thrust prediction scheme can be applied to the current design for the NanoSat 8 competition and results in an accurate prediction of thrust"--Abstract, page iii.
Download or read book Pulsed Plasma Thruster Plume Study Symmetry and Impact on Spacecraft Surfaces written by Lynn A. Arrington and published by . This book was released on 2000 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics of Electric Propulsion written by Robert G. Jahn and published by Courier Corporation. This book was released on 2006-05-26 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: Literaturangaben. - Originally published: New York, NY : McGraw-Hill, 1968
Download or read book Effect of Propellant Temperature on Efficiency in the Pulsed Plasma Thruster written by and published by . This book was released on 2003 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A pulsed plasma thruster (PPT) benefits from the inherent engineering simplicity-and reduced tankage fraction gained by storing the propellant as a solid. The solid is converted to the gaseous state and accelerated by an electric discharge across the propellant face. Previous research has concluded that as little as 10% of the consumed propellant is converted to plasma and efficiently accelerated. The remaining propellant is consumed in the form of late-time vaporization and particulate emission, creating minimal thrust. Critical to improving the PPT performance is improving the propellant utilization. The present work demonstrates one possible method of increasing the PPT propellant efficiency. By measuring the PPT thrust, propellant consumption, and propellant temperature while varying the power level, duration of the experimental run, and total propellant mass, a correlation is established between decreased propropellant temperature and increased propellant efficiency. The method is demonstrated by performance measurements at 60 W and S W, which show a 25% increase in thrust efficiency, while the propellant temperature decreases from 135 to 42 deg C. Larger increases in the efficiency may be realized on-orbit where operating temperatures are commonly subzero. The dependence of propellant consumption on temperature also creates systematic errors in laboratory measurements with short experimental runs, and orbit analyses where the PPT performance measured at one power level is linearly scaled to the power available on the spacecraft.
Download or read book Electromagnetic Effects in the Near Field Plume Exhaust of a Micro Pulsed Plasma Thruster written by and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work we present a model of the near field plasma plume of a Pulsed Plasma Thruster (PPT). As a working example we consider a micro-PPT developed at the Air Force Research Laboratory. This is a miniaturized design of the axisymmetric PPT with a thrust in the 10 micro-N range that utilizes Teflon(Trademark(sup Trademark)) as a propellant. The plasma plume is simulated using a hybrid fluid-PIC-DSMC approach. The plasma plume model is combined with Teflon(Trademark) ablation and plasma generation models that provide boundary conditions for the plume. This approach provides a consistent description of the plasma flow from the surface into the near plume. The magnetic field diffusion into the plume region is also considered and plasma acceleration by the electromagnetic mechanism is studied. Teflon(Trademark) ablation and plasma generation analyses show that file Teflon(Trademark) surface temperature and plasma parameters are strongly non-uniform in the radial direction. The plasma density near the propellant surface peaks at about 10(exp 24)/cu m in the middle of the propellant face while the electron temperature peaks at about 4 eV near the electrodes. The plume simulation shows that a dense plasma focus is developed at a few millimeters from the thruster exit plane at the axis. This plasma focus exists during the entire pulse, but the plasma density in the focus decreases from about 2x10(exp 22)/cu m at the beginning of the pulse down to 0.3x10(exp 22)/cu m at 5 microsec. The velocity phase is centered at about 20 km/s in the axial direction. At later stages of the pulse there are two ion populations with positive and negative radial velocity. Electron densities predicted by file plume model are compared with near field measurements using a Herriot Cell technique and very good agreement is obtained.
Download or read book Plume and Discharge Plasma Measurements of an NSTAR type Ion Thruster written by John E. Foster and published by . This book was released on 2000 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Arcjet Operating Condition and Constrictor Geometry on the Plasma Plume written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-10-06 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of plasma number density and electron temperature were obtained in the plumes of lab arcjet thrusters using electrostatic probes of both spherical and cylindrical geometry. The two arcjet thrusters used had different constrictor and/or nozzle geometries and operated on mixtures of nitrogen, hydrogen, and ammonia to simulate the decomposition products of hydrazine and ammonia. An increase in the measured electron density was observed for both geometries with increasing arc power at a constant mass flow rate and with increasing mass flow rate at a constant arc current. For a given operating condition, the electron number density decreased exponentially off centerline and followed an inverse distance squared relationship along the thrust axis. Typical measured electron temperatures ranged from 0.1 to 0.2 eV. Carney, Lynnette M. and Sankovic, John M. Glenn Research Center RTOP 506-42-31
Download or read book Advanced Electric Propulsion and Space Plasma Contactor Research written by Paul J. Wilbur and published by . This book was released on 1986 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Propellant Temperature on Efficiency in a Pulsed Plasma Thruster written by Gregory G. Spanjers and published by . This book was released on 1997 with total page 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 Propellant Surface Temperature and Plume Characteristics of Micro Pulsed Plasma Thrusters written by Erik Lawrence Antonsen and published by . This book was released on 2004 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Study of Plasma Parameter Distributions in Low Power Hall Effect and Ablative Pulsed Plasma Thrusters written by and published by . This book was released on 2003 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report results from a contract tasking Kurchatov Institute for the results of studying a stationary plasma-low power-thruster (SPT) and an ablative pulsed plasma one (APPT). In the first part of the Report the results of studying the module characteristic for a small SPT and for the thruster plume. In particular there are represented the description of test facility and system of thruster performance and plume parameter measurements as well as the results of these measurements. In the second part of the Report, the results of studying some features of the physical processes in APPT, as well as an analysis of the produced results based on the numerical simulation for increasing their efficiency, are represented. A two-dimensional model of APPT has been developed. lnterferometric investigations inside APPT discharge channel, piezoprobe measurements of dynamic pressure distributions and ultra high-speed photography with visualization of plasma flows have been carried out.
Download or read book A Performance Comparison of Pulsed Plasma Thruster Electrode Configurations written by and published by . This book was released on 1997 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stationary Plasma Thruster Plume Characteristics written by and published by . This book was released on 1994 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Plasma Jet Technology written by P. R. Dennis and published by . This book was released on 1965 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:
