Effect of airflow on the discharge uniformity at different cycles in the repetitive unipolar nanosecond-pulsed dielectric barrier discharge

This study explores the discharge uniformity at different cycles under different airflow velocities in nanosecond-pulsed dielectric barrier discharge. Based on a proper choice of the airflow velocity and discharge parameters, diffuse discharges can be maintained at an air gap of 5-7mm. At higher airflow velocities, the discharge may transition to a complex mode, in which the diffuse and filamentary regions are maintained simultaneously. When the discharge is operated at a higher frequency, higher voltage, or smaller gas gap, the area of diffuse discharge can be expanded to a certain extent. The discharge characteristics indicate that airflow lowers the gas temperature and modulates the preionization degree, which induces the generation of a diffuse discharge for a properly adjusted airflow velocity.