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Center for Nonlinear Studies |
Magnetohydrodynamics (MHD) is a reduced representation of plasma behavior wherein their highly complex behavior at the kinetic and particle scales is represented by macroscopic or fluid quantities such as mass density, momentum, and temperature. Among computational fluid dynamics methods the gas-kinetic scheme (GKS) has shown much promise in the last few years for applicability to a wide variety of fluid and gas flows. GKS is a finite volume scheme which uses a solution of the gas distribution function f to compute the macroscopic fluid fluxes across cell interfaces from moments of f in phase space [see e.g, Xu, 2001]. In previous developments GKS has been applied to ideal MHD [Xu, 1998; Tang and Xu, 2000; Tang et al., 2010]. Recent developments have produced the Magneto-Gas Kinetic Method (MGKM) for non-ideal/Hall MHD [Araya et al., 2015]. However, these approaches in applying GKS to plasma modeling and simulation have not yet been extended to the two- fluid MHD regime where fully separate electron and ion fluids are considered. In addition, they do not account for the effects of the magnetic field on the collisional non-equilibrium and do no include the transient effects of the electromagnetic fields and inter-species collisions on the evolution of the distribution. In this talk I will discuss some details the previous single-fluid MGKM development, and aspects of the gas-kinetic scheme. I will then focus on the details of extending GKS for application to the equations of two-fluid MHD, including fully accounting for the transient effects of the electromagnetic fields and collisions between electrons and ions in the solution of the distribution function f for each species during a time-step. This allows us to calculate enhanced macroscopic fluxes for both fluids.
Host: Luis Chacon