A Numerical Model of Streamer Breakdown in Air Gap at Atmospheric Pressure

摘要

This article presents a numerical model of streamer breakdown of sphere gap in air at atmospheric pressure. The streamer propagation is described by a system of equations, including charge continuity equation and Poisson equation. In addition, the photoionization effect is simplified and integrated into the model. The numerical results was performed and compared with the measurement of breakdown current. From the results, the increase of discharge current before the gap breakdown could be divided into three stages according to the development of each type of streamer.rnWe propose that the sphere gap will breakdown when positive streamer reaches the cathode and the rate of increase of discharge current is about 1.4 As.