Numerical Simulation of Incident Oblique Shock Wave Turbulent Boundary Layer Interactions on a Concave Cylinder

Shock wave/boundary-layer interactions are commonly encountered in the three-dimensional in⁃ ward-turning inlet. To better understand the flow physics of the interactions，a simplified model called the oblique shock wave impinging a concave cylinder was employed. Numerical simulations were conducted at a freestream Mach number of 6 with a series of θ（i.e.，the deflection angles）ranging from 6° to 14° to investigate the shock wave/boundary-layer interactions on a concave cylinder. The results show that the oblique shock wave/ concave cylinder interactions can be characterized by sweeping，impinging and reflection from upstream to down⁃ stream. The flow separation occurs since the oblique shock sweeps the concave cylinder. The classical quasi-coni⁃ cal symmetry is lost，since the shock interaction type between the incident shock and the separation shock is tran⁃ sited from Mach reflection to regular reflection. Then the thickening low-momentum fluid converges to the symme⁃ try plane，and enters the separation zone caused by the oblique shock impinging the concave cylinder，which in⁃ creases the length of the separation zone. With the increase of θ，the separation patterns evolve into different types. When θ≥10°，a streamwise counter-rotating vortex pair forms by the collision of the low-momentum fluid on the symmetry plane. When θ=14°，the tornado-like vortex in the separation pattern disappears. After the shock reflection，the low-momentum fluid converges to the symmetry plane，and its height continually increases along the streamwise direction. With the increase of θ，the total pressure recovery coefficient of the exit of the con⁃ cave cylinder decreases，while the total pressure recovery coefficient of the non-mainstream increases slightly. © 2023 Journal of Propulsion Technology. All rights reserved.