Pulsed Plasma Jets for Active Control of Shock Wave/Boundary Layer Interactions

ABSTRACT: The performance of supersonic inlets, actuators, and scramjet isolators is limited by shock wave/boundary layer interactions (SBLI). The adverse pressure gradient across a shock wave causes increased boundary layer thickness and often separation when it interacts with a boundary layer. This leads to increased total pressure loss and unsteadiness which can cause excessive thermal or structural loading. Control strategies to mitigate SBLI effects rely on bleeding the boundary layer upstream of the shock or enhancing the momentum transfer between the freestream and boundary layer. An ideal SBLI actuator will have low induced drag, high control authority, high frequency response, and low power requirements. Current actuators fall short in one or more of these areas. In the proposed effort, Creare and the University of Texas will develop pulsed plasma jet actuators for SBLI flow control. This type of actuator has demonstrated the potential for all the ideal actuator traits listed above. In Phase I, we will build and test novel actuator designs to determine their ability to reduce shock induced boundary layer deformation and separation. In Phase II, we will further develop the actuator design and control scheme to optimize it over a range of Mach numbers and shock types. BENEFIT: Technology derived from this program will be in the form of new SBLI flow actuators and actuator implementation schemes. These actuators may be applied to supersonic aircraft inlets, control surfaces, or scramjet isolators to reduce flow pressure loss and potentially damaging oscillations. The high frequency response of the actuators will allow them to be used in concert with new high-bandwidth control strategies for arresting scramjet unstart.