Development of a Performance Portable GPU Accelerated Fluid Solver for Non-Equilibrium Plasmas

In this paper, we present the numerical methods, programming methodology, verification, and performance assessment of a non-equilbirium plasma fluid solver that can effectively utilize current and upcoming central processing and graphics processing unit (CPU+GPU) architectures. Our non-equilibrium plasma fluid model solves the partial differential equations for species transport, electrostatic Poisson and electron temperature on adaptive Cartesian grids. Our solver is written using performance portable adaptive-grid/particle management library, AMReX, and is portable over widely available vendor specific GPU architectures. We present verification of our solver using method of manufactured solutions that indicate formal second order accuracy with central diffusion and fifth-order weighted-essentially-non- oscillatory (WENO) advection scheme. We also verify our solver with published literature on capacitive discharges and atmospheric pressure streamer propagation. We demonstrate the use of our solver on a three dimensional simulation of twin streamer propagation and merging in atmospheric pressure argon. We also show performance studies on three different CPU+GPU architectures for this three dimensional case indicating ~ 70-80X speed-up using NVIDIA and AMD GPUs per time step compared to a single CPU core for a two million cell simulation.