Numerical Analysis of Spatial Force Components in Direct Current Corona Field

Abstract

Digital procedure for description of boundary conditions and for computation of direct current two-dimensional corona field by use the finite difference method in polar coordinate system is discussed. Procedure involves the iterative solution of the system of corona field equations comprising the Poisson's equation and the continuity one. Maximum difference between the digital and test problem data for electrostatic field potential at the surface of the wire is only 0,13 %, and it is 6,4 % for field strength (for the number of nodes in computational area equal to 518). Comparison of digital corona field strength data and the data received by analytical formulas based upon the Deutsch‘s-Popkov‘s assumption show that the difference between them varies from 0,3 % at the surface of corona wire to 10,7 % on the surface of the plane electrode. Corresponding results for charge density are 8,1 % and 16,7 %. Digital data of volt-ampere characteristic for the discharge gap differ from analytical ones by 2,5 % and from experimental result by 4,5 %. The spatial force component Fr is dominant for all radial lines of the grid. The difference between the digital values of the component Fr and the corresponding values computed by analytical formulas increases from 9,3 % at the corona wire surface to 29,6 % on the surface of plate. Ill. 3, bibl. 6, tabl. 4 (in English; abstracts in English, Russian and Lithuanian).