Simulations of normal shock-wave/boundary-layer interaction control using mesoflaps

Computations were performed to investigate the flowfields of normal shock-wave/boundary-layer interactions with mesoflap control. The passive control (no feedback included) concept involves placing a mesoflap streamwise array beneath the interaction and allowing high-pressure air from the flow downstream of the shock wave to recirculate through a cavity into the low-pressure flow upstream of the wave. The case of a normal shock at a Mach number of 1.4 interacting with the turbulent boundary layer on a flat wall was first considered, and the predictions yielded reasonable comparison with experimental results. A number of fixed-deflection mesoflap simulations were then performed to understand the correlations between flap deflections, downstream boundary-layer characteristics, and stagnation pressure recovery. The prescribed steady-state deflections were based on qualitative aeroelastic experimental observations. It was found that the magnitude of the deflection of the upstream mesoflaps is key to providing a significantly increased "lambda-foot" benefit, which is critical for improved stagnation pressure recovery. The number of flaps and their locations were also found to affect the stagnation pressure recovery and downstream boundary-layer characteristics significantly. However, it was found that cavity depth does not play a significant role in stagnation pressure recovery.