Plasma Simulation from Two-Fluid to MHD in Complex Geometry Using Local Relaxation

ABSTRACT: Multidimensional simulation of plasmas will be critical to the design of high voltage and high energy density devices over coming decades. Individual fluid simulation codes are presently limited to one or perhaps two of three plasma models: the higher densities and longer time scales of magnetohydrodynamics (MHD), the lower densities and shorter time scales of extended MHD (XMHD), and the still lower densities and shorter time scales of the electromagnetic two-fluid model. A new approach, based on the relaxation method, implements a subset of the equations of the two-fluid model. This method is capable of providing results at both the MHD and XMHD densities and time scales. The model is robust and efficient owing to its ability to handle near-vacuum regions with only locally implicit equations. Very recent work has explored a relaxation method for an augmented version of the full two-fluid model. Our objective is to apply this relaxation method to the standard two-fluid model, on the two and three dimensional multiblock data structures and arbitrary coordinate grids of MACH2 and MACH3. We will prove the project"s feasibility by implementing the MHD/XMHD relaxation method within MACH2, and improving the relaxation method to the two-fluid model. BENEFIT: The two and three dimensional electromagnetic two-fluid codes based on the new relaxation method will be additions to NumerEx"s product line reaching out to the high power electromagnetic source market.