MONTE-CARLO SIMULATION OF NEUTRAL XENON FLOWS IN ELECTRIC PROPULSION DEVICES

Numerical simulations of neutral xenon how in three different electric propulsion configurations are presented. Flows through an ion thruste r, a plasma contactor, and a Hall thruster are considered. The computa tions are performed using a Monte Carlo method. The ion thruster confi guration chosen for study is the UK-10 engine. Comparisons of the simu lations are made with a simple analytical model that has been used in previous computations of backflow from ion thrusters. Both sets of the oretical results are compared with number density measurements. The Mo nte Carlo simulations provide closer agreement with the experimental d ata and the analytical model is found to overpredict density in the ba ckflow plume region. The Monte Carlo simulation of the plasma contacto r plume also compares well with experimental measurements. For the Hal l thruster, the simulations reveal detailed structures of the fluid fl ow in the annual anode chamber. Comparison with a measured data point for velocity indicates that the experiment is compromised by a relativ ely high facility back pressure. Inclusion of the back pressure in the simulation leads to excellent agreement with the datum.