Abstract
The characteristics of $NO-NO_2$ conversion and soot oxidation by corona discharge are investigated experimentally. The discharge current decreases with the increase of oxygen concentration and it increases more sharply for anode corona than for cathode corona as discharge voltage increases after corona onset voltage. $NO-NO_2$ conversion increases with the energy density of corona discharge and the addition of $O_2$ in a base $N_2$ gas. Soot oxidation occurs at approximately $480^{\circ}C$ in a mixture of 21% $O_2$, base $N_2$ gas, and enhances as temperature increases. The initiation temperature of soot oxidation advances greatly to about $280^{\circ}C$ with the addition of 300ppm $NO_2$, which is generated from the conversion of NO to $NO_2$ by corona discharge. CO is generated at higher temperature by about $50{\sim}100^{\circ}C$ than $CO_2$ in the process of soot oxidation.
