Leading edge slot blowing on an open cavity in supersonic flow

Supersonic flow over an open cavity can create intense pressure loads on the surfaces within the cavity. In order to combat these loads, the development of a control scheme to reduce them is becoming increasingly important for many engineering applications. The present study implements steady leading edge blowing through various configurations of spanwise-aligned rectangular leading edge slots. The effects of this control on the flow field were examined to determine the suppression mechanisms exploited by the leading edge blowing. The cavity studied here had a length-to-depth ratio of 6 and was placed in a freestream flow with a Mach number of 1.4. Actuators with one continuous slot and three and five segmented slots spanning the width of the cavity were installed at the leading edge. Surface pressure reductions of nearly 45% were achieved on the aft wall of the cavity using the 5-slot configuration. Velocity field measurements acquired through 2-component (streamwise-aligned measurement plane) and 3-component stereoscopic (cross-stream-aligned measurement plane) particle image velocimetry revealed the presence of streamwise-aligned vortices created by the segmented slots. These act to significantly alter the shear layer formed at the mouth of the cavity creating highly three-dimensional flow field features.