Induced flow direction of a single ehd plasma actuator using the one atmosphere uniform glow discharge plasma (OAUDGP)

Summary form only given. EHD plasma actuators have proven effective in delaying separation and re-attaching internal or external low speed flows in wind tunnel experiments that utilize drag balances, Pitot tubes, smoke flow visualization, and fluid dynamic modeling programs. Recent experiments showed that with the additional momentum from a single plasma actuator on its leading edge, the stall angle of a standard airfoil was increased from 15deg to 21deg with a free-steam flow velocity as high as 75 m/s. The induced flow should be laminar and parallel to the surface to realize flow re-attachment and minimize boundary layer turbulence. Some early experimental studies at the UT Plasma Sciences Laboratory and in the NASA Langley 7times10 low speed wind tunnel generally indicated that there exists no significant vertical component of induced velocity. These results were obtained with paraelectric plasma actuators having electrode gap distances d = 1 to 2 mm. However, there have been reports from experimental investigations and numerical simulations of plasma actuators that the flow velocity vector was lifting off the surface at an angle that could range up to 30 to 45 degrees. In this paper, we present the horizontal and vertical flow profile measurements for gapless and variable gap plasma actuators at selected values of RF frequency and RMS voltage