Corona discharge simulation in wire-duct electrostatic precipitator

This paper presents a numerical simulation methodology developed for the calculation of the electric field in wire-duct precipitation systems using finite differencing in orthogonal curvilinear coordinates to solve the potential equation. Charge density distribution is obtained by the method of characteristics or using a prediction-correction scheme. A new mesh-generation technique produces body-fitted orthogonal grids with lines similar to the field equipotential and characteristic curves, thus the requirements in grid nodes are kept low and the implementation of the method of characteristics becomes a very easy and fast task. Combining these advantages with a conjugate gradient solver the new methodology achieves high computational efficiency. Details for the convergence history, and the computer time requirements are given to allow comparison with other models. The numerical results are compared with several sets of experimental data from the literature, and their sensitivity to various model parameters (e.g. the corona onset gradient, the ionization zone thickness, and the criterion of convergence) is investigated.