SM/MURF: Current Capabilities and Verification as a Replacement of AFRL Plume Simulation Tool COLISEUM

Abstract : The Spacecraft Multi-Scale/Multi-Physics Universal Research Framework (SM/MURF) is currently in development at the in-space propulsion branch of the Air Force Research Laboratory (AFRL). This framework unifies multiple research codes developed independently at this branch and is intended to simulate plasma under a wide range of time and length scales relevant to the spacecraft electric propulsion (EP) systems. The current development effort focuses on the modernization of the AFRL plume simulation tool, COLISEUM. In this paper, all the operations for a plume simulation are reviewed along with the results from integration tests to verify the correctness of those operations. As the final verification test, SM/MURF and COLISEUM are used to perform the same baseline plume simulation, and the results from the two codes are compared. In general, the agreement between the two codes is very good. A slight discrepancy was caused by a mismatch of where the field data are computed; SM/MURF and COLISEUM compute field data on cell-centers and nodes, respectively. This results in a slightly different electric field, cascading through particle trajectories, field calculations, sputter rate, and redeposition rate onto spacecraft components.