Laminar hypersonic flow over compression ramp with sharp leading edge: separation and upstream influence*

The present work aims to study the effects of shock wave - boundary layer interaction in 2D hypersonic flow at the sharp leading edge of a flat plate. A key parameter in this work is the hypersonic interaction parameter Χ, defined as Χ ≡ C M_∞³ / Re_∞,L^1/2. This flow is modeled as a perfect gas and it's behavior is studied over various compression ramp configurations, ranging from 0° - 20°, using a semi-analytical reduced-order model. To study these resulting effects we focus on characterizing the viscous boundary layer for an adiabatic flow over an insulated wall, improving on existing semi-analytic methods in terms of obtaining a non-singular solution, and using the tangent wedge approximation to match the pressure on the boundary layer. Flow separation, which occurs at the compression ramp corner, is studied as a function of the ramp angle. Locations of flow separation and reattachment along the plate are predicted and compared with results obtained from a commercial flow solver. Upstream influence resulting from the compression ramp is also investigated and compared with previously developed correlations.