Numerical Investigation of Laminar Mach 6 Shockwave Boundary Layer Interaction

Laminar shockwave boundary layer interactions for a Mach 6 adiabatic wall, cooled wall, and strongly cooled wall case are simulated with a finite-volume and finite-difference code. The two-dimensional mean flow fields obtained with both codes are in good agreement. Three-dimensional simulations for the adiabatic and cooled wall reveal a growing steady three-dimensional mode. The temporal growth rate and mode shape are extracted via Fourier transforms and dynamic mode decomposition. In addition, biglobal stability analyses of the two-dimensional mean flow are performed. The results from the modal decomposition and biglobal analyses are compared with published data by Hildebrand et al. (Physical Review Fluids, Vol. 3, No. 1, 2018, p. 01390). A resolvent analysis for the adiabatic wall case reveals that the steady three-dimensional mode is receptive to forcing at separation. A biglobal and local stability analysis for the strongly cooled wall case uncovers an unsteady two-dimensional mode. Resolvent analysis indicates that the mode can be forced at separation or in the downstream part of the separation bubble.