Parallelization of a 2D fluid modeling code for non-thermal gas discharges

Abstract

Summary form only given. Progress in developing a parallelized 2D/2D-axisymmetric fluid and neutral flow modeling code (PFNF) for non-thermal plasma simulations is reported in this paper. Major modules of this PFNF include: 1) a fluid modeling code for gas discharge with power ranging from 10 kH-100 MHz, 2) a Navier- Stokes equation solver for neutral flow, and 3) a coupled external circuit analysis code. The fluid modeling code solves charged species continuity equations using drift-diffusion approximation for the particle flux term, electron energy density equation, Poisson's equation, and Maxwell equation. The Navier-Stokes equation solver solves the continuity equation, momentum equations and energy equation for the mass-averaged neutral flow, which is capable of modeling conjugate heat transfer for solid and gas. The external circuit analysis code applies Kirchoff's current law by considering the external RLC and plasma together at the same time. All model equations are nondimensionalized and discretized using fully implicit finite-difference method with Scharfetter- Gummel scheme for the fluxes in the fluid modeling equations and exponential scheme for the fluxes in the Navier-Stokes equations. Both backward Euler and higher-order temporal schemes are included. All transport coefficients of charged species and rate constants of chemical reactions can be expressed as the nonlinear function of electron temperature or gas temperature. The resulting discretized nonlinear coupled equations are then solved by the parallel Newton-Krylov-Schwarz (NKS) algortihm, in which the overlapping additive Schwarz method (ASM) and bi-CGSTAB scheme is used as the preconditioner and linear matrix equation solver, respectively. Parallel performance is tested on a PC cluster system (IBM-13 50 at NCHC of Taiwan) up to 128 processors. Several test cases, including quasi-1D, quasi-1D-radial, and 2D-axisymmetric parallel plate under various operating conditions will be presented in the presentation.