Simulation on branching phenomena of discharge channel in short SF6 gap under nonuniform electric field

The experimental observations indicate that streamers in short gap always exhibit irregularity and self-similarity, so the random fractal method can be applied to simulate this phenomenon. In this paper, a two dimensional stochastic streamer discharge process which combines the traditional streamer theory and fractal growth theory in non-uniform electric field under time domain is simulated to quantify the channel tortuosity of short SF6 gap. The box counting method is used to characterize the channel tortuosity and estimate the fractal dimensions of discharge channels. In addition, influences of both applied voltage and streamer channel conductivity of discharge channels are also analyzed.