The Generation and Evolution of a Diffuse Nanosecond Pulsed Dielectric Barrier Discharge in Airflow

Atmospheric-pressure dielectric barrier discharge (DBD) with airflow participation has been widely used in recent years. In this experimental study, a diffuse DBD excited by repetitive nanosecond pulses is achieved in airflow. Upon the introduction of airflow to the gas gap, the discharge state transforms from a filamentary one into a diffuse one at first, followed by the generation of a thin filamentary discharge (TFD) at a high airflow rate. It is observed that the diffuse discharge (DD) and the TFD are ignited from the electrode boundary, which subsequently move toward the downstream region with a velocity below the corresponding airflow rate. Subsequent to hundreds of pulse cycles, a stationary discharge state is formed with the TFD in the upstream region and the DD in the downstream region. The length of the TFD region is associated with the airflow rate, the pulse repetition frequency (PRF), and the applied voltage. The observations presented above are ascribed to the transverse electric field at the electrode boundary and the redistribution of charges under the action of airflow.