Statistics of 2D multi-mode iso-thermally stratified compressible Rayleigh-Taylor instability*

The flow compressibility through the strength of the background stratification has been reported to have a stabilization effect in single-mode 2D Rayleigh-Taylor instability (RTI) at Atwood numbers less than 0.05. This work extends the study of such effects on the low Atwood number (A=0.04) 2D RTI to the multi-mode perturbation using direct numerical simulations, DNS. We study the growth of the RTI, mixing, energetics, and the vortical dynamics of the flow with different Mach and Reynolds numbers. In addition, we present a detailed analysis of our DNS to study how compressibility plays a role in the transport of Turbulent Kinetic Energy, TKE, of the multi-mode 2D RTI.