Compressibility effects on shock-turbulence interaction

Direct numerical simulation (DNS) and inviscid linear analysis (LIA) are used to study the interaction of a normal Mach 1.5 shock wave and isotropic turbulence. The influence of the nature of the incoming turbulence on the interaction is emphasized. The presence of upstream entropy fluctuations enhance the amplification of the turbulent kinetic energy and transverse vorticity variance across the shock compared to the solenoidal (pure vorticity) case. More reduction of the transverse Taylor microscale is also observed in the vorticity-entropy case while no influence can be seen on the longitudinal microscale. When acoustic and vortical fluctuations are associated upstream, less amplification of the turbulent kinetic energy, less reduction of the transverse microscale and more amplification of the transverse vorticity variance are observed through the discontinuity. All the DNS results are in good qualitative agreement with LIA