Nanosecond pulsed surface discharge plasma actuator with nonplanar substrate

Plasma streamers propagating on the nonplanar surface under the negative pulsed voltage powered show different behaviors with those on the flat surface. Detachment and branching of plasma streamer are observed. The streamer stride over the groove valley and the charge on the crest of the groove initiates a new streamer branch sliding along the groove wall, propagating in the different direction with the streamer trunk. With third electrode introduced, plasma streamer shows an enlarged distributing zone, and the merge of two streamers’ fronts occurs on the both sparse and grooved surface, which cannot be obtained on the flat surface with single or two powered electrodes existence. Due to the different voltage amplitude loaded on the two powered electrodes, two asymmetrical plasma streamers appear. As for the generated electrohydrodynamic (EHD) force and induced flow filed, the third powered electrode obviously enhances the intensity and zone of the EHD force, the induced intense and wildly distributed vortices around the grooves shows potential on improvement of EHD force density.