Alterations in Critical Radii of Bluntness of Shock Wave Boundary Layer Interaction

Abstract

Any configuration consisting of flat plate attached to a ramp experiences shock wave boundary layer interaction (SWBLI) at supersonic or hypersonic Mach numbers. This interaction can lead to flow separation at the ramp foot. In that case, its extent depends on the leading-edge radius of the plate. At a specific radius (inversion radius), the separation bubble size attains maximum value, and at particular leading-edge bluntness (equivalent radius), the length of the separation bubble becomes equal to that of the sharp leading-edge case. Values of these critical radii need to be evaluated for complete understanding of dynamics of SWBLI. Therefore, numerical simulations are carried out to estimate these values with change in freestream Mach number, wall temperature, and freestream stagnation enthalpy. Thicknesses of the high-entropy layer and boundary layer, along with wall pressure distribution, are considered for analyzing the influence of these parameters on the estimation of critical radii. The magnitudes of both the radii have been observed to increase with a decrease in Mach number and stagnation enthalpy. Freestream static and total temperatures are found to have dimensional dependence on the flow field for moderate leading-edge radii instead of their ratio. Therefore, present studies are useful in understanding and accessing the effect of freestream conditions and wall temperature on the values of critical radii.