Experimental and numerical investigation of shock wave/boundary layer interactions induced by curved back-swept compression ramp

Abstract

When integrated with supersonic/hypersonic flight vehicles the ramp shock/boundary layer interaction occurs in streamline-traced inward-turning inlets exhibit complex three-dimensional characteristic. Two simplified flow models named the single-sided model and the double-sided model were abstracted to investigate the flow phenomenon in this paper. The single-sided model was designed to focus on curved ramp shock/boundary layer interaction near the corner of the inlet while the double-sided model aimed to expose the coupling mechanism and the evolution process near the symmetry plane of the inlet. The separation region of the single-sided model was observed to develop along the leading edge of the three-dimensional compression ramp using oil flow visualisation. It started at the junction of the ramp and the sidewall, spanned the whole test model, and appeared as a ‘scimitar’ shape with a maximum streamwise length of 0.58δ0. On the other hand, a symmetry separation pattern was observed in the double-sided model. The separation region was ‘crescent-shaped’, originated from the junctions of the ramp and two sidewalls, and coalesced at the symmetry plane, inducing a maximum streamwise separation scale of 0.78δ0 on the symmetry plane. The measured surface pressure distributions showed that the shock wave/boundary layer interactions in the two models behaved similarly around the ramp-sidewall junction.