DOI: 10.1615/TSFP9
ASYMPTOTIC SIMILARITY STATES OF UNSTABLY STRATIFIED HOMOGENEOUS TURBULENCE
RESUMO
We study the late time dynamics of unstably stratified homogeneous turbulence (USHT) accounting for incompressible binary mixture under Boussinesq approximation. In order to explore the high Reynolds number regimes reached at long times, which cannot be represented in either laboratory experiments or direct numerical simulations, we use a spectral model based on the eddy damped quasinormal Markovian (EDQNM) closure. We focus in this study on the dependence of the asymptotic regime on the large scale distribution specified in initial conditions, specified by the powerlaw scaling of the infrared spectral range. We are able to identify the various evolutions of kinetic energy corresponding to distinct self-similar states, characterized by the kinetic energy growth rate and the anisotropic structures created in the flow. Our results agree with recent theoretical predictions concerning USHT.