Characterization of a Supersonic Wind Tunnel for the Study of Supersonic Inlet Flow Control

The geometry and the nature of supersonic flow in supersonic mixed compression inlets generate internal shock wave/boundary layer interactions (SWBLIs). Shock waves generated by the inlet cause internal boundary layer disruptions that lead to inlet inefficiencies and possible boundary layer separation. Boundary layer separation is undesirable because it reduces mass flow to the engine and can lead to choking of the inlet or unstart. Current flow control methods are effective in reducing the separation, but are yet to significantly increase the inlet efficiency. Researchers at the Gas Dynamics and Turbulence Laboratory (GDTL) have proposed a new control technique using localized arc-filament plasma actuators (LAFPAs). The LAFPAs are to be tested in a supersonic blow down wind tunnel with a compression ramp shock generator. The characterization of the baseline flow of this facility is vital to researching control of the interaction. Several qualitative and quantitative flow diagnostics were used to characterize this Mach 2.3 flow. The interaction generated in this tunnel was shown to be a separated SWBLI comparable with those studied in literature. It was also found to exhibit the expected low frequency unsteady behavior.