Shock waves can generate high levels of turbulent fluctuations in temperature, pressure and
other thermodynamic properties. These have significant role in turbulent mixing, heat transfer
and acoustic noise in high-speed flows. The thermodynamic fluctuations generated by canonical
shock-turbulence interaction are strong functions of the shock strength and the upstream
turbulence intensity. For a fixed shock Mach number, the downstream thermodynamic
variances, normalized by the upstream turbulence kinetic energy, are found to increase with the
incoming turbulent Mach number (Mt). This is in contrast to the trend observed for Reynolds
stresses and the turbulent dissipation rate. We use direct numerical simulations and linear
interaction analysis to investigate the effect of Mt on the post-shock thermodynamic field. It is
found that the presence of small amount of acoustic and entropy fluctuations in the incoming
flow can explain the high intensity of the post shock thermodynamic variances in the high Mt
cases.
Keywords: compressible turbulence, shock waves, pressure fluctuations, temperature variance, Kov´asznay modes, linear analysis