Interrelation of phase-averaged volume force and capacitance of dielectric barrier discharge plasma actuators

Simultaneous measurements of the phase-averaged velocity distribution and the underlying discharge quantities of a dielectric harrier discharge plasma actuator (PA) are performed at 10 kHz discharge frequency to investigate the interplay of the discharge and the surrounding flow. The underlying velocity information for the force estimation is obtained by means of phase-averaged particle image velocimetry; the discharge quantities are determined from a Lissajous-figure analysis. The results uncover a clear cause effect relation between the phase-dependent effective discharge capacitance of the PA and the resulting spatiotemporal volume-force distributions. From this novel insight, it must he concluded that the instantaneous effective discharge intensity dominates the momentum-transfer rate rather than the formerly assumed operating voltage.