Shock-induced turbulent boundary layer separation can have many detrimental effects in supersonic inlets including flow instability, fatigue of structural panels, poor pressure recovery, flow distortion, and unstart. The current study investigated the effect of pulsed plasma jets on the recovering boundary layer downstream of a reflected shock wave-boundary layer interaction at several run conditions. Three actuator configurations were tested: 20° pitch, 0° skew, 1.8 mm exit diameter; 20° pitch, 0° skew, 2.5 mm exit diameter; and 40° pitch, 45° skew, 2.5 mm exit diameter. The actuators were tested with pulsing frequency of 700 Hz, 1000 Hz, 1500 Hz, 2000 Hz and 3000 Hz. The jet exits were placed at a distance of 5 mm from the separated region. A traversable pitot probe is used to measure the velocity profile of the boundary layer 35 mm downstream of the plasma jets, and the degree of boundary layer distortion is compared between the different models and run conditions. Additionally, the effect of each actuator configuration on the shape of the mean separated region is investigated using surface oil flow visualization. Measurement results are compared to unsteady RANS simulations of pulsed and steady jets interacting with a shock-separated flow. It was found that at a forcing frequency of 2000 Hz, the large exit diameter 20° pitch jet locally displaces a section of the mean separation line by approximately 30% of the scale of the separated region, and all configurations locally displace the mean separation line by 10-15% of the separation scale. However, very little effect is seen in the downstream recovering boundary layer. Immediately downstream of reattachment, shape factor, displacement thickness and friction coefficient seem to be shifted by 2-3%, but this is within measurement uncertainty. The wake parameter is more affected, shifting by as much as 10%, just outside measurement uncertainty. Far downstream, any observable effects are gone except for a weak shift in wake strength. Comparison with the simulations suggest that this is at least partially due to insufficient heating of the gas in the jet cavity by the electrical discharge.
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