Ionic wind in pin-to-plate corona discharge system

Electroaerodynamic investigation has been carried out in a pin-to-plate gas discharge system to clarify the mechanism of repulsive force generation between the pin and the plate electrode at corona discharge. Numerical calculation has been conducted by two steps. At the first place, corona discharge field was calculated with the finite element method to deduce volumetric force ρE, where ρ is the charge density and E is the electric field, applied to the air, and then induced ionic wind was calculated with the finite differential method. Calculated pressure distribution on the plate electrode was in the order of 10 Pa that was in good agreement with the measured pressure distribution. Calculated velocity at the center was several m/s that is confirmed by a time-of-flight experiment and the velocity distribution near the pin electrode also agreed with the measured with a laser Doppler velocimeter. Pressure and wind velocity were increased at high applied voltage. These results confirm that the ionic wind is the cause of the repulsive force to the pin electrode at the corona discharge.