Numerical Analysis of the Fluid Field near the Corona Wire due to the Corona Discharge : The Vortex Formulation and the Fluid Force on the Wire

Abstract

The purpose of this paper is to examine fluid flow around a wire electrode, induced by corona discharge in a system of wire and plate electrodes, in order to give some information for the self- excited lateral oscillation of the wire electrode. First, Maxwell's equations governing electrostatic field are calculated numerically in order to obtain the Coulomb force on the fluid particle, distributed throughout the space. Second, the Navier-Stokes equation with a term of external Coulomb force is calculated numerically by the finite difference method. The fluid flow around the wire electrode is obtained after the calculation of the fluid flow between the wire and plate electrodes. As a result, a symmetric pair of fixed vortexes is formed in the wake of the wire electrode. However, there is no vortex shedding from the wake caused by the corona discharge. Moreover, it is suggested that the fluid force on the wire electrode can not necessarily neglected as the excitation force if the wire oscillation is self-excited as the galloping type mechanism.