Small Business Innovation Research/Small Business Tech Transfer
Multiscale Modeling of Hall Thrusters, Phase I
Project Description
New multiscale modeling capability for analyzing advanced Hall thrusters is proposed. This technology offers NASA the ability to reduce development effort of new high power Hall thrusters, and reduce system complexity and increase system lifetime and durability. Historically, efforts to model Hall thrusters utilized either hybrid/fluid approach which reduce computational overhead but rely on analytical fits, or required prohibitive computational resources to model thrusters self-consistently. Even with the use of large supercomputers, the self-consistent approach was limited to small, low power thrusters. We propose a new approach in which electron transport along magnetic field lines is computed self-consistently using a kinetic code for electrons, but global cross-field properties are computed using a 2D hybrid code. This approach combines the benefits of fully kinetic self-consistent modeling with the performance gain of hybrid models. The model will be able to analyze Hall thruster discharges without requiring any user-specified mobility fits. The model will also require only computational resources available in a standard desktop workstation. In addition, ions exiting the thruster will be sampled to generate a discretized source model for use with subsequent thruster plume modeling. Plume modeling is necessary to optimize thruster spacecraft coupling, and reduce possible instrument and spacecraft component contamination effects. These three components, magnetic field line, thruster discharge, and the spacecraft environment, form the three scales of our multiscale approach. In this effort we will concentrate on extending the capability of modeling thruster discharges by developing a new light-weight hybrid code with built in support for kinetic mobility modeling.
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Anticipated Benefits
The product that will be developed under this proposal will directly benefit NASA by providing it with a tool capable of analyzing the influence of various system variables during the design process of new high power Hall thrusters. Possible uses include selection of wall materials to reduce electron energy losses, selection of wall materials to improve thruster lifetime, optimization of magnetic circuit to take advantage of effects such as the magnetic mirror and magnetic lens, optimization of thruster geometry by utilizing non-conventional designs such as cylindrical or multi-channel configuration, and optimizing the electron currents produced by the cathode to reduce plume divergence and thus reduce plume divergence. Predictive thruster model will in addition serve as a source model for plume modeling of the thruster integrated on a spacecraft. This will allow the mission designer to optimize the placement of the thruster on the spacecraft to reduce secondary interaction of plume particles with sensitive spacecraft sensors and components. The need to simplify the design and analysis, and reduce the inherent complexity of Hall thrusters is not limited to NASA. Other government entities, including the Air Force, have an existing need for such programs. Our effort will be applicable to both the high power Hall thrusters proposed by NASA, as well as low power thrusters being investigated by other government entities and commercial partners for near-Earth operations such as station keeping and orbit rising. The simulation tool that will be developed under this effort can thus also serve private industry, companies such as Aerojet, Busek that are developing Hall thrusters and will be able to use this predictive tool in the design process. In addition, we plan to leverage the lessons learned in this effort to further enhance multiscale modeling capability for rarefied gas applications. One such topic includes modeling of space environment interactions. The spacecraft community in large is in need of codes that can predict potential contamination and charging events, and their effect on spacecraft operation. Of interest is the wall interaction of plasma particles. The domains of interest (spacecraft system) are of size too large to allow direct modeling of wall interaction details. Multiscale modeling of the system is thus required.
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Primary U.S. Work Locations and Key Partners
| Organizations Performing Work | Role | Type | Location |
|---|---|---|---|
| Particle in Cell Consulting | Lead Organization | Industry | Falls Church, Virginia |
Glenn Research Center
(GRC)
|
Supporting Organization | NASA Center | Cleveland, Ohio |
Primary U.S. Work Locations
-
California
-
Ohio
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This is a historic project that was completed before the creation of TechPort on October 1, 2012. Available data has been included. This record may contain less data than currently active projects.