Multiscale Modeling of Streamers: High-Fidelity Versus Computationally Efficient Methods

Abstract

2D axisymmetric streamer model is presented, using the fluid drift-diffusion approx- imation and the Hyridizable Discontinuous Galerkin (HDG) numerical method for spatial discretization. Numerical verification of the newly developed code is performed against the literature, demonstrating very good agreement with state-of-the-art codes, and results are presented for single-filament streamers using a plate-to-plate geometry, both with and without photoionization. Full-physics numerical models, such as the one presented, are computationally costly and not prone to parametrically studying streamers. Reduced order models of streamers are of interest to quantitatively relate streamer macroscopic parameters, but they need to be compared to higher-fidelity models to demonstrate their validity. In this contribution, the macroscopic parameter streamer model recently developed by our group is validated against the higher-fidelity model. The macroscopic parameter streamer model is based on the results of a reduced-order 1.5D quasi-steady model (i.e., 1D solution of the species continuity equations, 2D solution of Poisson equation, solved in the reference frame of the streamer). The comparison shows that the general trends captured by the macroscopic model, in terms of radius, speed, tip electric field and channel electric field relations, are in agreement with the results of the higher-fidelity simulations and limitations of the predictions are discussed.