Effect of the EHD Force on the Spatial Distribution of Neutral Species Generated by a Positive and Negative Corona Discharge

In this work, positive corona and negative corona are investigated numerically to compare their respective species productions and spatial distributions in dry air, assuming a parallel wire-to-plate electrode configuration and a stationary discharge. The electrohydrodynamic (EHD) force, which is at the origin of the EHD flow (or ionic wind), is computed by means of a simplified analytical model. This force is used in Navier-Stokes equation, which is solved along with the continuity equations for neutral species. The gain/loss rates of neutral species are determined from a plasma-chemical model that includes the most important reactions between electrons, atoms and molecules. The numerical solution of these equations allows us to compare the effect of the corona wire polarity on the 2D spatial distribution of neutral species and their corresponding number densities. The simulation results show that the effect of the EHD flow on the species distribution is greater in the case of negative corona. In the case of ozone, the spatial distribution inside the reactor is approximately similar in both coronas but, in negative corona, the concentration of ozone is around three orders of magnitude higher than that in the positive corona.