Multi-scale study of the transitional shock-wave boundary layer interaction in hypersonic flow

A high-fidelity simulation of the massively separated shock/transitional boundary layer interaction caused by a 15-degrees axisymmetrical compression ramp is performed at free stream Mach number 6 and transitional Reynolds number. The chosen configuration yields strongly multiscale dynamics flow as region oscillates low-frequency, high-frequency instabilities are triggered injection generic noise inlet simulation. post-processed using Proper Orthogonal Decomposition to extract large scale low-frequency recirculation region. bubble from then compared results global linear stability analysis about mean flow. critical interpretation eigenspectrum linearized Navier–Stokes operator presented. found be dominated two coexisting modes, quasi-steady one that expresses itself mainly in reattachment self-sustained instabilities, an unsteady linked with separation shock-wave mixing layer. mode driven feedback loop region, which may also relevant for other shock-motion already documented shock-wave/turbulent interaction. impact large-scale on assessed through numerical filtering those low wavenumber modes; they have no dynamics.