Experimental Investigation on a Multicathode Dielectric-Barrier Discharge: Effects of Airflows

The dielectric-barrier discharges (DBDs) under airflow have been widely used in the fields of airflow control, plasma-assisted combustion, and surface modification. Our previous work demonstrates that the discharge intensity under airflows could be adjusted by a discharge configuration with upstream and downstream electrodes. In this paper, a further investigation of discharges under airflows is processed with a multicathode DBD configuration. With the injection of airflows to the discharge region, the first upstream region produces a decrement of discharge intensity, while the following downstream region always provides greater discharge intensity than that of the adjacent upstream discharge region. An optimal discharge configuration is found by appropriately selecting the distances between the cathodes, wherein the last downstream region can produce maximum discharge intensity. The mechanisms are analyzed by considering the transport effect of airflows and the lifetime of charged and metastable particles. The charged and metastable particles are transported to the downstream region, and these particles always act as the responsible seeds to enhance the downstream discharges. In addition, due to the limited lifetime of charged and metastable particles, the enhancement effect may be weakened under long transport distances. Finally, potential applications for multicathode DBDs are also provided.