The effect of surface charge distribution on the electrohydrodynamic force in dielectric barrier discharge plasma actuators

We experimentally investigate the relationship between the charge distribution on a dielectric surface and electrohydrodynamic force produced by a dielectric-barrier-discharge (DBD) plasma actuator. The surface potential distributions are measured using the Pockels effect. We found that the saturation time of the surface potential takes hundreds of milliseconds, which shows a large difference in the time scale of the surface discharge (several nanoseconds). Also, the electric potential distribution strongly depends on a biased DC voltage and the electrode configuration of the DBD plasma actuator. In particular, an additional exposed electrode placed downstream prevents the electric field screening. As a result, the electrohydrodynamic force is significantly enhanced by adding the exposed electrode since the electric field downstream contributes to the acceleration of charged particles. In the presentation, we are going to discuss the surface charge dynamics and its effect on the mechanical performance of the DBD plasma actuators in detail.