2-D corona field computation in configurations with ionising and non-ionising electrodes

An efficient method is proposed for the Computation of the electric field strength and of the space-charge density in configurations of at least three ionising and non-ionising electrodes. The physical model is derived under the assumptions commonly accepted for the study of corona fields. The mathematical model makes use of a conformal mapping that converts the actual boundary-free field zone into a rectangular domain with well-defined boundary conditions. The finite-difference method is then used for solving the differential equations that describe the ionic space-charge and electric field distribution. The computational procedure was employed for studying the simple case of the drift zone of the corona discharge generated between a so-called dual electrode and a grounded plate. The dual electrode consisted of an ionising wire (diameter 0.22 mm) located at 20 mm from a tubular metallic support (diameter 25 min). The computed current-voltage characteristic and current density distribution at the surface of the collector plate were in good agreement with the experimental data obtained for this combined corona-electrostaties electrode arrangement. (c) 2005 Elsevier B.V.. All rights reserved.