Numerical investigation of shock/film-cooling interaction

In this numerical study, a film-cooling flow with shock-wave interaction is analyzed using large-eddy simulation (LES). A laminar cooling film at an injection Mach number of Ma_i = 1.8 is injected through a slot into a fully turbulent boundary layer at a freestream Mach number of Ma₁ = 2.44. An oblique shock, generated by a flow deflection of β = 5∘ or 8∘, impinges upon the cooling film within the potential-core region. At a deflection angle of β = 5∘, the cooling effectiveness downstream the shock impingement is decreased by 4.6% compared to the undisturbed flow configuration. A flow deflection of β = 8∘ leads to a decrease in cooling effectiveness of 13.4%. The separation bubble at the shock impingement position causes a strong negative peak of the Reynolds shear stress near the wall. With increasing shock strength, the separation bubble significantly grows in size. The separation length of the strong shock configuration is increased by a factor of 4.6 compared to the weaker shock configuration.