Download or read book PIC Simulation of SPT Hall Thrusters written by Kay Ueda Sullivan and published by . This book was released on 2004 with total page 83 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fully kinetic Hall Thruster simulation built by [1] and used by [2] is further refined and used to obtain results for the P5 SPT Hall thruster at 3kw and 5kw operation. Performance data agree well with experiments [3], although very low values of anomalous diffusivity must be used for convergence. Particle temperatures and plasma potentials in the chamber are similar to experimental results, although charged particles and peak ionization rates are found further upstream than is observed experimentally. Electron transport mechanisms and the magnetic field configuration are analyzed for their physical consistency and effect on particle placement. Electron mobility rates are found to be physical although the reason for high Hall parameter is still unclear. Strong magnetic mirror effects, that are not reported in experimental data, are found in the simulation. Meanwhile, two sputtering models are added to the simulation and tested. A yield model based on [4]'s theories and implemented with [5]'s functions is found to agree well with experimental yield data for 300eV to 1000eV sources, but produces small yields at thruster operating conditions.

Download or read book Particle In Cell Simulation of a Ceramic lined Hall effect Thruster written by Vincent Blateau and published by . This book was released on 2002 with total page 202 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 Dynamic Models of Electron Transport in Hall Thruster Simulations written by Eunsun Cha and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Hall-effect thruster (HET) is an electrostatic propulsion device that relies on the Hall effect to generate a dense ExB electron current to ionize the propellant gas. In simulating Hall thrusters, describing electron cross- eld transport has been one of the greatest challenges because the electron transport in a Hall thruster is anomalously higher than that predicted by classical collision theory. Researchers have suggested some explanations of the anomalous transport, but they have failed to establish a reliable physical model for general applications. Establishing a physical model that is applicable to various types of Hall thrusters in various operating conditions is an objective of this work. In this thesis, a 2-D hybrid particle-in-cell (PIC) simulation for the Stanford Hall thruster (SHT) is used to implement the transport (electron mobility) models. Among various attempts, an entropy closure model, as well as a turbulent transport model were successfully implemented and demonstrated results that show reasonable agreement to measured data. The entropy closure model uses a 1-D entropy transport equation in the plasma of a Hall thruster discharge to derive a relation for electron mobility as a function of other plasma properties. The simulated results show a reasonable agreement with experiments. The turbulent transport model seeks for a more straightforward way to incorporate the entropy production mechanism into the simulation. By assuming that the Joule heating is the main source of entropy production, we adopted the turbulent kinetic theory to relate the energy dissipated from the largest eddies with the energy production rate. Through a scaling analysis, electron mobility is expressed as an explicit function of other plasma properties of the simulation. The simulated electron mobility captures the electron transport phenomenon measured experimentally. To test the transportability of the turbulent model, the simulation was modi ed for an SPT-type thruster with a different geometry than the SHT. Also, an alternative propellant, molecular nitrogen, was simulated on the geometry of the SHT using the turbulent model. The dynamic mobility models make it possible to observe the dynamic characteristics of the Hall thruster. The mobility models in this study magnify the capability of Hall thruster simulations to explore design space cost effectively.

Download or read book Parallelization of Particle in cell Simulation Modeling Hall effect Thrusters written by Justin M. Fox and published by . This book was released on 2005 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt: MIT's fully kinetic particle-in-cell Hall thruster simulation is adapted for use on parallel clusters of computers. Significant computational savings are thus realized with a predicted linear speed up efficiency for certain large-scale simulations. The MIT PIC code is further enhanced and updated with the accuracy of the potential solver, in particular, investigated in detail. With parallelization complete, the simulation is used for two novel investigations. The first examines the effect of the Hall parameter profile on simulation results. It is concluded that a constant Hall parameter throughout the entire simulation region does not fully capture the correct physics. In fact, it is found empirically that a Hall parameter structure which is instead peaked in the region of the acceleration chamber obtains much better agreement with experiment. These changes are incorporated into the evolving MIT PIC simulation. The second investigation involves the simulation of a high power, central-cathode thruster currently under development. This thruster presents a unique opportunity to study the efficiency of parallelization on a large scale, high power thruster. Through use of this thruster, we also gain the ability to explicitly simulate the cathode since the thruster was designed with an axial cathode configuration.

Download or read book Very Near Field Plume Model of a Hall Thruster written by F. Taccogna and published by . This book was released on 2003 with total page 2 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plasmadynamic phenomena of a stationary plasma thruster (SPT-100) plume in the very-near-field region have been studied by using a two-dimensional axysimmetric numerical code based on a combination of Particle in Cell (PIC) simulation for ion component (Xe+ and Xe++) and fluid description for electrons. The model can reproduce qualitatively several experimental observations.

Download or read book Advances in Fully kinetic Particle in cell Simulations of Near vacuum Hall Thruster and Other Plasma Systems written by Justin M. Fox and published by . This book was released on 2007 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Cont.) In addition, this simulation extended the state of the art in Hall thruster anomalous diffusion modeling by adopting a "quench rule" which is able to predict the spatial and temporal structure of the cross-field transport without the aid of prior empirical data. Truly predictive computations are thus enabled. After being thoroughly tested and benchmarked, the simulation was then applied to the near vacuum Hall thruster recently constructed at MIT. Recommendations to improve that thruster's performance were made based on the simulation's results, and those optimizations are being experimentally implemented by other researchers. This work was conducted with the aid of Delta Search Labs' supercomputing facility and technical expertise. The simulation was fully-parallelized using MPI and tested on a 128 processor SGI Origin machine. We gratefully acknowledge that funding for portions of this work has been provided by the United States Air Force and the National Science Foundation.

Download or read book Two Dimensional Particle in cell Simulation Model for Hall Type Thrusters written by Penh Koetwongjun Beidler and published by . This book was released on 1999 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of the Plasma Thruster Particle in cell Simulator to Complement Empirical Studies of a Low power Cusped field Thruster written by Stephen Robert Gildea and published by . This book was released on 2013 with total page 285 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cusped-field plasma thrusters are an electric propulsion concept being investigated by several laboratories in the United States and Europe. This technology was implemented as a low-power prototype in 2007 to ascertain if durability and performance improvements over comparable Hall thruster designs could be provided by the distinct magnetic topologies inherent to these devices. The first device tested at low-powers was eventually designated the "diverging cusped- field thruster" (DCFT) and demonstrated performance capabilities similar to state-of-the-art Hall thrusters. The research presented herein is a continuation of these initial studies, geared toward identifying significant operational characteristics of the thruster using experiments and numerical simulations. After a review of hybrid, fluid, and particle-in-cell Hall thruster models, experimental contributions from this work are presented. Anode current waveform measurements provide the first evidence of the distinct time-dependent characteristics of the two main modes of DCFT operation. The previously named "high-current" mode exhibits oscillation amplitudes several factors larger than mean current values, while magnitudes in "low-current" mode are at least a full order smaller. Results from a long-duration test, exceeding 200 hours of high-current mode operation, demonstrate lifetime-limiting erosion rates about 50% lower than those observed in comparable Hall thrusters. Concurrently, the plasma thruster particle-in-cell (PTpic) simulator was developed by upgrading numerous aspects of a preexisting Hall thruster model. Improvements in performance and accuracy have been achieved through modifications of the particle moving and electrostatic potential solving algorithms. Data from simulations representing both modes of operation are presented. In both cases, despite being unable to predict the correct location of the main potential drop in the thruster chamber, the model successfully reproduces the hollow conical jet of fast ions in the near plume region. The influences guiding the formation of the simulated beam in low-current mode are described in detail. A module for predicting erosion rates on dielectric surfaces has also been incorporated into PTpic and applied to simulations of both DCFT operational modes. Two data sets from highcurrent mode simulations successfully reproduce elevated erosion profiles in each of the three magnetic ring-cusps present in the DCFT. Discrepancies between the simulated and experimental data do exist, however, and are once again attributable to the misplacement of the primary acceleration region of the thruster. Having successfully captured the most significant erosion profile features observed in high-current mode, a simulation of erosion in low-current mode indicates substantially reduced erosion in comparison to the more oscillatory mode. These findings further motivate the completion of low-current mode erosion measurements, and continued numerical studies of the DCFT. Additionally, PTpic has proven to be a useful simulation tool for this project, and has been developed with adaptability in mind to facilitate its application to a variety of thruster designs -- including Hall thrusters.

Download or read book Hybrid Particle in cell Modeling and Electrostatic Probe Survey of Hall Thrusters written by John Michael Fife and published by . This book was released on 1998 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analytical and Numerical Study of a Hall Effect Thruster with a Particle in cell Model written by Alejandro Benítez Martín and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Space propulsion, and more specifically electric propulsion, has been growing widely strong for the last 20 years thanks to the increasingly frequent technological advances in this field. That's why there are plenty of studies arising seeking for new ways of computing simulations of propulsion systems. This is the case of the Particle-in-Cell method. This method is nowhere near new, for it started being used in the 1950s, but the computational advances in the recent years have opened new doors for this numerical method that makes it one of the best options. So, this thesis has the main purpose of proving that Particle-in-Cell simulations of a onedimensional Hall-effect thruster channel give similar results to experimental data obtained via analytical models. For it, first an introduction to different electric propulsion systems and plasma physics will be done in order to have the basis of Hall thrusters functioning so the analysis can be performed. Once the basis are settled, the analytical model will be performed comparing the results with those obtained by professor E. Ahedo and then, using the results obtained in the analytical model as reference, the numerical model using the PIC method will be computed. Finally, by discussing and comparing the two models, we will see that the results obtained in both models resemble a lot those obtained by professor E. Ahedo and the experimental data from real life thrusters, with the only difference that some discrepancies appear. In the case of the analytical model, values in electrons temperature will tend to have a sudden decrease due to not taking into account wall losses and plume divergence, while in the PIC numerical model a little oscillation appears at the beginning due to the finite difference solver used. Although the appearance of such discrepancies, the results obtained are exactly the ones that were expected, hence proving the viability of the PIC model for plasma computation.

Download or read book Fully kinetic Particle in cell Simulations for Hall effect Thrusters written by Justin M. Fox and published by . This book was released on 2007 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: (cont.) This thesis details the implementation and thorough benchmarking of that new simulation. The work was conducted with the aid of Delta Search Labs' supercomputing facility and technical expertise. The simulation was fully-parallelized using MPI and tested on a 128 processor SGI Origin machine. We gratefully acknowledge that funding for portions of this work has been provided by the United States Air Force Research Laboratory and the National Science Foundation.

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 Numerical Models of Hall Thruster Ionization Oscillations written by Ewan Samuel Kay and published by . This book was released on 2016 with total page 143 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, low frequency ionization oscillations in Hall thrusters resembling the breathing mode are studied through computational simulation. The relationship between wall erosion and discharge current oscillations is analyzed using particle-in-cell simulation, and a series of parametric simulations is used to determine the effects of macro-particle size, floating body potential, electron injection region, ion time step size, grid refinement, heavy particle mass reduction, and an artificial permittivity factor. These studies help to determine the parameters that will produce accurate simulations in the future, and identify the parts of the model that need improvement. One-dimensional steady and unsteady Hall thruster models, as well as a generalized sheath model are then developed, and the effects of the parameters that determine stability on the thruster’s operating conditions are determined.

Download or read book Numerical Simulations of the Plumes of Electric Propulsion Thrusters written by Douglas Bryan VanGilder and published by . This book was released on 2000 with total page 370 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 2023-10-25 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fundamentals of Electric Propulsion Understand the fundamental basis of spaceflight with this cutting-edge guide As spacecraft engineering continues to advance, so too do the propulsion methods by which human beings can seek out the stars. Ion thrusters and Hall thrusters have been the subject of considerable innovation in recent years, and spacecraft propulsion has never been more efficient. For professionals within and adjacent to spacecraft engineering, this is critical knowledge that can alter the future of space flight. Fundamentals of Electric Propulsion offers a thorough grounding in electric propulsion for spacecraft, particularly the features and mechanisms underlying Ion and Hall thrusters. Updated in the light of rapidly expanding knowledge, the second edition of this essential guide detailed coverage of thruster principles, plasma physics, and more. It reflects the historic output of the legendary Jet Propulsion Laboratory and promises to continue as a must-own volume for spacecraft engineering professionals. Readers of the second edition of Fundamentals of Electric Propulsion readers will also find: Extensive updates to chapters covering hollow cathodes and Hall thrusters, based on vigorous recent research New sections covering magnetic shielding, cathode plume instabilities, and more Figures and homework problems in each chapter to facilitate learning and retention Fundamentals of Electric Propulsion is an essential work for spacecraft engineers and researchers working in spacecraft propulsion and related fields, as well as graduate students in electric propulsion, aerospace science, and space science courses.

Download or read book Flexible Three Dimensional Modeling of Electric Thrusters in Vacuum Chambers written by and published by . This book was released on 2003 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: A national team of researchers is developing a software system, COLISEUM, which performs calculations of plasma propagation and interaction with arbitrary 3%D surfaces. The applications of COLISEUM are wide- ranging, hut include simulating engine test configurations inside vacuum chambers and predicting sputtering and re-deposition on spacecraft surfaces. COLISEUM allows users to easily define complicated 3-D geometries using off the shelf CAD software, then select from a set of plasma expansion models of varying fidelities and numerical complexity to perform the solution. Once the object surfaces are created, the user can run different types of simulations for the same geometry. With this system, low fidelity models can he used to verify the geometry and boundary conditions, and to obtain first-order predictions. Higher fidelity models are then used to obtain more accurate predictions with greater cost in computation time. This paper describes the simulation of a Hall thruster firing inside a vacuum chamber, and the execution of two types of simulations for the same geometry: one in which the equilibrium sputter and deposition rates are calculated, and another in which the Hall thruster plume expansion is calculated. The sputter and deposition calculations are made with an iterative ray tracing algorithm which takes into account re-sputtering of deposited material. The plume expansion calculations are performed with a particle-in-cell (PIC) algorithm which includes wall collisions and wall recombination. Techniques are incorporated that decrease the computation time required for the PIC simulation to relax to steady state.