Direct Numerical Simulation of Magnetohydrodynamic Thruster Plasmas
The lithium Lorentz force accelerator (LiLFA) is a promising high-power (50-500 kW) plasma thruster for spacecraft propulsion, particularly interplanetary missions. We have employed direct numerical simulation (both finite volume and finite element) to simulate the flowfield of various configurations of this device and investigate the physical processes that influence thrust, efficiency, and fundamental physical processes that cannot be obtained by experimental diagnostics. Numerically solving the governing equations of magnetohydrodynamics requires substantial computational resources – parallel computation for anything but the simplest problems. The regime of propulsive plasmas introduces additional challenges: multi-level ionization, anomalous resistivity, and Hall effect physics to name a few. Mathematically, this leads to an increasingly stiff system of equations, with the associated increase in required computational resources. In this talk I will discuss some of these issues and how we have utilized parallel computation on the Princeton Plasma Physics Lab Beowulf cluster and the Lawrence Berkeley National Lab NERSC cluster to obtain new insight into LiLFA operation.