Propagation of Cathode-Directed Streamer Discharges in Air

Y. Serdyuk[1]
[1]Chalmers University of Technology, Gothenburg, Sweden

Streamers are considered as main cause of electrical breakdown in air at atmospheric pressure. A streamer is an ionization wave propagating in neutral gas which is converted into low-temperature plasma behind its front. A streamer model is based on drift-diffusion approach where space and time evolution of densities of charge carriers is considered. It results in three convection-diffusion PDEs coupled with Poisson’s equation for electric potential and Helmholtz equations for photo-ionization in the gas. An implementation of the model is presented. Two study cases are shown for a short and long streamers in a needle-plane electrode system. The obtained characteristics of the discharges match well with experimental data. Improvements needed to be introduced in the numerical model are discussed.