Unified gas-kinetic wave-particle methods IV: multi-species gas mixture and plasma transport

Abstract In this paper, we extend the unified gas-kinetic wave-particle (UGKWP) methods to multi-species gas mixture and multiscale plasma transport. The construction of scheme is based on direct modeling mesh size time step scales, local cell’s Knudsen number determines flow physics. proposed has asymptotic complexity diminishing properties. property means that according can capture non-equilibrium physics when cell kinetic mean free path scale, preserve Euler, Navier-Stokes, magnetohydrodynamics (MHD) hydrodynamic scale much larger than particle path. total degrees freedom reduce automatically with decreasing number. continuum regime, degenerates from a solver solver. UGKWP, evolution microscopic velocity distribution coupled macroscopic variables, as well fluxes modeled accumulating solution transport collision up scale. For transport, current provides smooth transition particle-in-cell (PIC) method in rarefied regime magnetohydrodynamic regime. limit, UGKWP are not restricted by time. highly magnetized Debye length cyclotron period. properties verified numerical tests multiple regimes.