Experiments on Resonance Enhanced Pulsed Microjet Actuators in Supersonic Crossflow

Abstract

An array of high-bandwidth, high-momentum pulsed supersonic microjets, called Resonance Enhanced Microjets (REM), were implemented to study the effect of pulsed actuation in a M=1.5 supersonic cross flow over a flat plate. Cross correlated, phase locked flow imaging and unsteady pressure measurements were used to characterize the shock wave-boundary layer interactions resulting from the pulsed actuation. Pulsed microjet actuators in supersonic cross flow have generated oblique shocks whose strength and shock angle are observed to have an invariable correlation with the pulsing phase of the microjets. Unsteady pressure measured downstream also shows a strong correlation to the pulsing phase of the actuator and the resulting oblique shock properties. These experiments clearly point to the potential capabilities of the resonance enhanced microjet actuator to manipulate the unsteady properties of the boundary layer of a supersonic flow.