Electrohydrodynamic interaction induced by a dielectric barrier discharge

In the present work an experimental investigation on the electrohydrodynamic (EHD) interaction effect, induced by means of a dielectric barrier discharge on a 1 atm subsonic air flow, is described. The air flow is obtained in an open circuit blowing wind tunnel at different air speeds. A plane plasma panel equipped with a dielectric discharge barrier system is immersed in the flow. A single phase sinusoidal power supply system, a superposition of a single phase sinusoidal system with a dc voltage supply, and a three phase symmetrical power supply configuration are considered. Electric, fluid dynamic, and spectroscopic diagnostic techniques are utilized. Pitot probe measurements are performed in the boundary layer on the plasma panel surface. Schlieren imaging is done to visualize the plasma sheath. Vibrational and rotational temperatures are evaluated by means of spectroscopic techniques. The force induced on the flow by the dielectric barrier discharge acts on the ions of the non-neutral sheath ahead of the plasma filament when travelling on the panel surface only. This causes a reduction of the time interval during which the force is active. The EHD effect and the momentum transfer to the gas flow in the boundary layer are reduced when the flow speed grows. An increase of the supply frequency and of the supply voltage causes an increase of the momentum transfer. In these experiments no significant increase of the efficiency of EHD effect is observed when utilizing the superposition of a dc voltage to a single phase power supply or a three phase power supply. (C) 2008 American Institute of Physics.