Numerical study of plasma dynamics and electrohydrodynamic effect in DBD plasma actuator

Discharge plasma evolution of DBD plasma actuator was numerically simulated to analyze the electrohydrodynamic (EHD) force field which is the source of the wall-surface jet generation of DBD plasma actuator. The simulation was conducted in the three-dimensional space, and three-dimensionality of the discharge and EHD force field was discussed in detail. As a result, many micro-discharges repetitively appear in the three-dimensional simulation. Although many of them appears at random position on the electrode edge, some of them appear at the same position. These discharge characteristics are in good agreement with observations in experiments. The EHD force field is also spanwise non-uniform corresponding to the plasma structure. To analyze the effects of the three-dimensional non-uniformity on the fluid, three-dimensional CFD simulation of the induced wall-surface jet was also conducted using the EHD force field obtained in the plasma simulation. The result indicated that not only transverse but also longitudinal vortex structures are generated, and the transverse vortex breaks into many small vortices with downstream advection.