Three-dimensional flow features of swept impinging oblique shock/boundary-layer interactions

An experimental investigation has been conducted to assess the flow structure in the interaction of a swept impinging oblique shock with a turbulent boundary layer. While representing a fundamentally simplified non-dimensional interaction, the behavior of flow in this geometry has not been assessed at Mach numbers below the hypersonic regime. Three angles of sweep (ψ_sg = 0:0°, 22:5°, and 40:0°) have been assessed on a shock genera- tor with x-y plane deflection angle of θ_sg = 12:5° in Mach 2.3 and Mach 3.0 incoming flow with a turbulent boundary layer using a combination of pseudo-color schlieren photography and oil-flow visualization. Significant flow three-dimensionality is observed when testing without endplates to the point where a quasi-2D impinging oblique shock cannot be established. After limiting leakage at the shock generator root and increasing the aspect ratio of the interaction channel, quasi-infinite span interactions have been induced for all swept cases and visualized here. In addition, a 3D inviscid model of the interaction has been constructed to determine the onset of inviscid detachment - previously associated with the cylindrical-conical interaction development boundary. However, experimental results suggest that the onset of conical interactions is below that predicted by the inviscid model, in agreement with similar observations on swept compression ramps.