Electro-Hydrodynamics and Kinetic Modeling of Dry and Humid Air Flows Activated by Corona Discharges

The present work is devoted to the 2D simulation of a point-to-plane Atmospheric Corona Discharge Reactor（ACDR） powered by a DC high voltage supply.The corona reactor is periodically crossed by thin mono filamentary streamers with a natural repetition frequency of some tens of kHz.The study compares the results obtained in dry air and in air mixed with a small amount of water vapour（humid air）.The simulation involves the electro-dynamics,chemical kinetics and neutral gas hydrodynamics phenomena that influence the kinetics of the chemical species transformation.Each discharge lasts about one hundred of a nanosecond while the postdischarge occurring between two successive discharges lasts one hundred of a microsecond.The ACDR is crossed by a lateral dry or humid air flow initially polluted with 400 ppm of NO.After 5ms,the time corresponding to the occurrence of 50 successive discharge/post-discharge phases,a higher NO removal rate and a lower ozone production rate are found in humid air.This change is due to the presence of the HO2 species formed from the H primary radical in the discharge zone.