Flow control with electrohydrodynamic actuators

The ability of an electrohydrodynamic actuator to modify the characteristics of a flow over a flat plate is analyzed. The device considered uses flush-mounted electrodes and a dc power supply to create a plasma sheet on the surface of the plate. We analyze the mechanism of formation of this plasma sheet, which has some similarities with the phenomenon of streamer formation. Experimental results are presented concerning flow visualizations obtained at low flow velocities (approximate to 1 m/s) and velocity fields obtained with a particle image velocimetry technique for higher flow velocities (range 11.0-17.5 m/s). These results show that the discharge can induce an important acceleration of the flow close to the surface.