Welcome to the new Indico service!
Nordita Astrophysics seminars

Turbulent fluxes of entropy and internal energy in temperature stratified flows

by Prof. Igor Rogachevskii (Ben-Gurion University of the Negev)

Europe/Stockholm
122:026 ()

122:026

Description
We have derived equations for the mean entropy and the mean internal energy in the low-Mach-number temperature stratified turbulence (i.e., for turbulent convection or stably stratified turbulence), and shown that turbulent flux of entropy is different from the turbulent convective flux in the equation for the mean internal energy. This turbulent convective flux is well-known in astrophysical and geophysical literature, and it cannot be used as a turbulent flux in the equation for the mean entropy. This result is exact for the low-Mach-number temperature stratified turbulence and is independent of a model. We also derived equations for the velocity-entropy correlations in the limits of small and large Peclet numbers, using the quasi-linear approach and the spectral tau approximation, respectively. This study is important in view of different applications to the astrophysical and geophysical temperature stratified turbulence.