3D Turbulent Boundary Layer Separation Control by Multi-Discharge Plasma Actuator

Abstract

In a subsonic wind tunnel, a three-dimensional separation of a developed turbulent boundary layer was simulated on a swept wing flap model. A multi-discharge plasma actuator operating on the basis of dielectric barrier discharge was used to overcome the positive pressure gradient, leading to a three-dimensional separation, when the ultimate streamline on the aerodynamic surface turns along the flap trailing edge. The actuator created an extended streamwise region of volume force, leading to flow acceleration near a streamlined surface. The influence of the force impact direction relative to the flap trailing edge was studied. The experiments demonstrated that the plasma actuator can significantly influence the flow structure in the separation region, leading to a decrease in both the transverse size of the viscous wake behind the flap and the total pressure losses within it.