The Shock and the Turbulence: the story of an interaction

The interaction of turbulence with a shock wave is a fundamental prob-lem in fluid mechanics relevant to a wide range of fields and applications including aeronautics (supersonic flight and propulsion), astrophysics (su-pernovae explosions, accretion shocks), nuclear physics (inertial confinement fusion), and medicine (shock wave lithotripsy). The canonical problem of isotropic turbulence passing through a nominally planar shock is the sim-plest configuration that isolates the fundamental physical phenomena at play in such interaction. The controlling parameters of the interaction are the Taylor microscale Reynolds number, Reλ, and turbulent Mach number, Mt, of the incoming isotropic turbulence and the mean Mach number, M, that characterizes the shock strength. The study of this canonical problem is addressed in [1] and [2] through direct numerical simulations (DNS) of varying Reλ (from 40 to 70), Mt (from 0.05 to 0.38) and M (from 1.05 to 6). The linked Video 1 (for a lower reso-lution version, see Video 2), was obtained from a simulation performed with Reλ = 40, Mt = 0.38 and M = 1.5 on a grid containing 1040×3842 points, and highlights some features of this interaction in four different sections: • Shock meets turbulence: the shock, which is nominally planar and nor-mal to the mean velocity by which the isotropic turbulence is advected, is corrugated by the passage of turbulence. Local packets of faster-than-average velocity push the shock downstream, leading to zone