Turbulent mixing driven by a spherical converging shock

We present recent results from large-eddy simulations of the mixing induced at a perturbed spherical density interface initially impacted by a spherically convergent shock wave of Mach number $\simeq1.2$ at impact, and then re-shocked in the expansive phase. Two configurations are compared: i) air inside and SF$_6$ (five times denser than air) outside, i.e. heavy--light configuration; ii) SF$_6$ inside and air outside, or light--heavy configuration. From data interpolated over spherical surfaces, we compute various power spectra as well as extensive surface-averaged statistics involved in the budget of turbulent kinetic energy and enstrophy density.