Unsteadiness of the Control of Shock-Induced Boundary-Layer Separated Flow Using Supersonic Fluidic Oscillator

In supersonic flows with a freestream Mach number of 2.4, the turbulent boundary layer could be separated by an oblique shock wave. The characteristics of the unsteadiness change of the separated flow were experimentally observed when various flow control techniques were applied to control the separated flows. The unsteadiness of the separated flows were analyzed and compared for two different control techniques applied ahead of the separation location; a conventional control technique using supersonic jet ejection and a recently developed supersonic fluidic oscillator. Measurement of high-frequency response pressure guages and statistical analysis of the measured signals were employed to compare the unsteadiness of the separated flows for various locations and control pressures of the control devices, and the fluidic oscillator operated in a specific condition was observed to have favorable control performances.