Adaptive multiscale methods for 3D streamer discharges in air

Abstract

We discuss spatially and temporally adaptive implicit-explicit (IMEX) methods for parallel simulations of three-dimensional fluid streamer discharges in atmospheric air. We examine strategies for advancing the fluid equations and elliptic transport equations (e.g. Poisson) with different time steps, synchronizing them on a global physical time scale which is taken to be proportional to the dielectric relaxation time. The use of a longer time step for the electric field leads to numerical errors that can be diagnosed, and we quantify the conditions where this simplification is valid. Likewise, using a three-term Helmholtz model for radiative transport, the same error diagnostics show that the radiative transport equations do not need to be resolved on time scales finer than the dielectric relaxation time. Elliptic equations are bottlenecks for most streamer simulation codes, and the results presented here potentially provide computational savings. Finally, a computational example of 3D branching streamers in a needle-plane geometry that uses up to 700 million grid cells is presented.

arXiv comment17 pages, 5 figures

References in corpus (5)

• The multiscale nature of streamers
• Simulating streamer discharges in 3D with the parallel adaptive Afivo framework
• Interaction of streamers in air and other oxygen-nitrogen mixtures
• Spatially hybrid computations for streamer discharges with generic features of pulled fronts: I. Planar fronts
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Cited by in corpus (2)

• The physics of streamer discharge phenomena
• 3D fluid modeling of positive streamer discharges in air with stochastic photoionization