Control of Shockwave Boundary Layer Interaction Using Nanosecond Pulsed Plasma Actuators

Shockwave boundary layer interactions (SWBLI) have been studied extensively over the past decades due to their impact on aerodynamic performance of high-speed vehicles. Significant effort has focused on controlling SWBLI using both passive and active flow control methods. In this work, dielectric-barrier-discharge (DBD) plasma actuators, powered by a nanosecond repetitively pulsed (NRP) high voltage source, are used to control the SWBLI provided by a 25-degree ramp flow in Mach 2 flow. The plasma actuator is imbedded in the surface upstream of the ramp, and rapid localized heating produced by the plasma is used to perturb the boundary layer. Such perturbations have been shown to affect the location and dynamics of the unsteady separation shock downstream, however, the physics of the control mechanism are not well understood. In this work, the control authority and mechanism are investigated using several diagnostics, including pressure measurements in both streamwise and spanwise locations, schlieren visualization, and high-speed quantitative density measurements using background oriented schlieren (BOS). The actuator design and initial measurements and characterization of the base and perturbed flow are presented.