Numerical simulations of electric propulsion systems in a Low Earth Orbit #

Ivan Barranco Gomez, Chris Toomer, Karen Aplin, Andrew Lawrie

14:10 Tuesday in 4Q07.

Part of the Industrial mathematics session.

Abstract #

Throughout this presentation an ion electrospray thruster and an ion thruster are modelled at an altitude of 550km and simulated numerically. This altitude is chosen in order to model the environment which current constellation satellites lie in, such as SpaceX’s StarLink network. A 2-D axisymmetric, kinetic Particle-in-Cell approach is used in order to model the plume of both thrusters. The aim is to obtain a deeper understanding on the effect each of these thruster plumes have on the plasma sheath formation around a satellite. This highlights the importance in improving the current existing hardware and numerical models available. There is an increasing concern for the detrimental effects that slow-moving ions may have on spacecraft over large periods of time, more specifically the impact these particles may have on solar arrays. A hybrid collision algorithm scheme is used comprising of Direct Simulation Monte Carlo (DSMC) and Monte Carlo Collisions (MCC) It contains a variation of different hard sphere (HS) models corresponding to the available data on the chosen propellants. Different propellants are evaluated in order to review the plasma plume shape, behavior and overall performance of these thrusters. These propellants include xenon, which is historically the most used propellant; iodine, which is considered a future propellant due to its affordability; and 1-ethyl-3-methylimidazolium tetrafluoroborate (EMI-BF_4) which is commonly used in ion electrospray propulsion systems. Furthermore, possible particle contamination is discussed.