Numerical Simulation of Corona Discharge in wire-to-cylinder configuration using Comsol Multiphysics

Summary

Corona discharge is used in various ways in an increasing number of engineering applications. The analysis of ionized fields in different geometrical electrode arrangements has an important area of research. One of the configurations mostly used for theoretical and experimental studies is the wire-to-cylinder geometry, largely used in the design of the electrostatic precipitator (ESP). This paper deals with the numerical modelling of the corona discharge in atmospheric air in a coaxial type ESP. The corona governing equations are successfully implemented and solved using COMSOL MULTIPHYSICS, a commercial software package used in various physics and engineering applications to solve a wide range of partial differential equations by applying the finite element method. Three application modes are used to solve system of coupled equations with appropriate boundary conditions: PDE (General Form) mode for electric potential distribution, Convection and Diffusion mode for charge transport equation, and a PDE (Weak Form, boundary) mode to impose to the electric field to be equal to the threshold value at the wire surface. To investigate the effectiveness of the proposed method, the computed current-voltage characteristic has been compared with the experiment characteristic; good correspondence between both indicates the value of the method. This method represents a descriptive model with no explicit or implicit dependence upon the first Deutsch assumption, wherein space-charge affects the magnitude but not the direction of the electric field. Comparison of the shapes of the field lines with and without the presence of space-charge indicates that this assumption is not valid. The computational values of space charge density, electric field and electric potential distributions are also presented. The Comsol program is fairly simple and very quickly with high precision. It can be extended to more complex geometries for corona ionized fields.

Additional informations

Authors

Homma Hiroya, Tsovilis Thomas