Numerical and simulation model of the streamer inception at atmospheric pressure under the effect of a non-uniform electric field

摘要

This paper introduces a new approach of breakdown theory using a computer simulation program. Based on the concept of Minimum Stressed Volume Zone (MSVZ) a simulation model of the streamer inception in air using the needle-to-plane configuration is presented. The streamer methodology first requires accurate field computation. The non-uniform electric field distribution is conducted using Poisson's equation, which is solved based on the concept of the Finite Element Method (FEM). The advantage of using FEM in the simulation of streamer progression is the ability to simulate the potential solution for a non-uniform field gap with the external injection of charges at the beginning of each streamer step. The simulation confirms that the streamer radius is 30 mu m, with 10(8) electrons at the streamer tip, then within MSVZ the radius of the streamer filament enlarges to a value of 120 mu m, so, the radius of the streamer leader near stressed high voltage electrode becomes constant at 120 mu m. After that, when the simulated field (E) at the main leader head is supply energy with eight times of critical electric field (E-cr) value, i.e. the electric field at its tip reaches a value of E/E-cr = root 8; the streamer starts to branch; thus, a value of E-cr of 4.5 kV/cm required for streamer initiation. The new simulation model is assessed via a comparison with other experimental and computational works.