Shock wave interaction with boundary layer at ramp surface

The supersonic flow of cold air of 64 K with Mach=5.85 over a 2-D ramp of 16 degrees is modeled numerically assuming laminar, transitional and turbulent boundary layer models. Finite-volume approach and ANSYS/FLUENT software were used. The unitless surface pressure coefficients were obtained computationally and compared to surface pressures obtained by AFRL experiments for upstream and downstream surfaces with respect to the ramp corner. Generation of the numerical grid capturing the influence of the shock wave-associated pressure jump on the boundary layer is discussed. The 5-equations Reynolds Stresses turbulence model and 4-eq transitional model are believed to be the most accurate. The size of the upstream zone of influence is obtained in terms of surface pressure coefficient. The effects of ramp wall temperature on the wall friction coefficient are evaluated and found to be minor. Comparison with experimental data in terms of pressure coefficient shows that the turbulent flow model is applicable for total pressure P=1400 psi while the laminar flow model is more applicable to capture upstream surface pressure coefficient for P=700 psi.