A PIV Study of a Plasma Discharge Flow-Control Actuator on a Flat Plate in an Aggressive Pressure Induced Separation

Abstract

An experimental study was performed to examine the effect of a dielectric barrier discharge plasma flow control actuator. The actuator was applied to a flat plate boundary layer in a pressure distribution approximating that of the suction side of an aft-loaded low-pressure turbine blade. Particle image velocimetry was used to obtain two-dimensional velocity field data on four boundary layers with velocity profiles that included fully attached laminar, turbulent, nominally separated and high-separated. Values of Rec ranged from 4500 to 75,000. For the separated boundary-layers the actuator was located downstream of the separation point. Four E-fields were characterized for each case. The actuator was able to induce boundary layer reattachment even when located downstream of the initial separation point. The length scale over which this re-attachment occurs was strongly dependent upon the applied E-field. The actuators also caused significant reduction in the overall boundary layer thickness as a result of the modification of the near-wall static pressure distribution.