Induced flow simulation with detailed discharge modeling in dielectric-barrier-discharge plasma actuator

The flow field induced by a dielectric-barrier-discharge (DBD) plasma actuator is complicated because the electrohydrodynamic (EHD) force depends on the applied voltage waveform and the electrode configuration. In this study, fluid-discharge coupling simulation was performed to reproduce the induced flow field driven by the DBD plasma actuator in the atmospheric pressure. The induced flow structure was reproduced with the detailed discharge simulation when a DC-voltage combined with repetitive nanosecond pulses was applied. The DC voltage generates a large EHD force at the beginning; however, the EHD force decreases with time because the electric field is screened due to the surface charge accumulation. The negative pulse voltage ignites a pulsed discharge and neutralizes the dielectric surface, which is positively charged during the DC phase, forming a two-stroke charge cycle. This operation method repetitively generates a large EHD force. A wall jet parallel to the dielectric surface is induced with the two-stroke charge cycle operation. The peak velocity is approximately 4 m/s when the 8-kV DC voltage combined with the -8 kV nanosecond pulses is applied. Shock waves are also repetitively generated due to the fast gas heating at the exposed electrode tip during the pulse superposition phase.