Research On The Hybrid Numerical Method And Analytical Model Of Streamer Propagation

Streamer widely exists in different forms of gas discharge, discovering the law ofstreamer propagation is very important for the study of the physical mechanism of the gasdischarge and engineering design of high voltage and insulation. In the past century, manyscholars have adopted different methods (experimental, theoretical deduction andnumerical simulation) to achieve the basic properties of streamers. However, streamerpropagation is a physical process which changes acutely in space and time. As a result, itis quite difficult to measure the microscopic parameters. Numerical simulation can makeup for its shortcomings, but is limited by the gap size and computer resources, and alsowith an algorithm difficult to implement. Moreover, the existing analytical models can notbe a comprehensive description of the development process of the streamer and some ofthem also depend on the results from numerical simulation.This paper firstly proposed a hybrid finite element-finite difference-flux correctedtransport method (h-FE-FD-FCT), using the finite element method to solve the electricfield in the space and the finite difference-flux corrected transport method for solving thetransport equations and then described the basic properties of streamers in uniform electricfield and non-uniform electric field. This numerical method combines the advantage offinite element (easy-to-handle irregular boundary) and finite difference (efficient insolving the transport equations). Finally, based on the theoretical basis of the gas discharge,the experimental data and numerical simulation results, two analytical models forstreamers in uniform electric field and non-uniform electric field were presented. Theresults from numerical and analytical models, including uniform electric field, the gasbreakdown electric field, and the initial delay time, velocity, spatial and temporaldistribution of space charge and the electric field of streamer are in good agreement withthe published experimental and simulation results.