Electric field and EHD flow in longitudinal wire-to-plate DC and DBD electrostatic precipitators: A numerical study

Abstract

In this study, the electrical and electrohydrodynamic (EHD) flow properties of a wire-to-plate electrostatic precipitator with a longitudinal wire electrode are investigated through a numerical simulation. The two modes of operation are considered: DC and AC supply voltages. The AC model features dielectric layers over collecting electrodes, hence a dielectric barrier discharge mechanism. To predict the ion concentration on the wire electrode surface, Kaptzov's hypothesis is employed. Both electrical and fluid flow equations are solved using the Finite Element Method. The EHD flow properties are estimated by simulating electric field, space charge density and fluid flow in the 3D precipitator channel. The results suggest that 1000 Hz frequency in AC supply generates EHD force with a 9 × 10⁴ N/m³ maximum alue, which is an order of magnitude higher than the same value under DC supply. However, for 100 Hz supply voltage frequency the EHD force is lower than that for the DC supply and equal to 8 × 10³ N/m³, although with a greater level of vorticity. The proposed models for DC and AC supply voltages display close characteristics to their experimental references with an average relative error of 13.5%.