The simulation of streamer dynamics in the air gap

The air gap breakdown at high altitude is attracting more and more attention from investigators. As the altitude increases, air pressure and humidity varies, discharge in air gap becomes more complex. The streamer propagation is a significant physical process during air gap breakdown. Research on streamer characteristic is helpful for understanding the mechanism of air gap breakdown. In the paper, a simulation model of streamer dynamics was carried out using fluid model. The numerical results of streamer dynamics were compared with the experiment results which had been published in former paper under different air pressure and humidity. Good agreement between test and numerical computation at stability propagation field is obtained, which demonstrates the validity of the simulation model of streamer dynamics. Then, the simulation model was adopted to study the influence of background electric field, duration and amplitude of voltage pulse on streamer propagation. With the rising of duration and amplitude of voltage pulse, the intrinsic stability field for streamer propagation and corresponding propagation velocity decrease.