Simulation of Positive Streamer Discharge in a 0.5 cm Air Gap

Abstract

The aim of the work is to simulate the dynamic of positive streamer in a plane-to-plane gap filled with air at 300K and atmospheric pressure. A simulation was performed using 2-dimensional axisymmetric fluid model. The model was constructed using the finite element method (FEM) and a time-dependent solver in the commercial computer package COMSOL Multiphysics version 6.0. Ionization by electron impact, attachment, and recombination are among the chemical reactions taken into account in this model. By solving the drift-diffusion equations for ions and electrons in conjunction with Poisson's equation, the mobility of charged species is simulated. Modeling results showed that (i) the strong electric field surrounding the streamer's head cause a notable enlargement of the streamer head. The electric field values needed to bridge the gap were E_br=32 kV/cm (ii) the positive streamer's particle density falls between 10¹³-10¹⁴ cm^-3 and the breakdown time for the short gaps occurs in several nanoseconds.