indico  First event Previous event Nordita Astrophysics seminars Next event Last event   | view:  |  manage export to personal scheduler  | 
user login 

 

Turbulent fluxes of entropy and internal energy in temperature stratified flows
  Nordita Astrophysics seminars

Wednesday 03 June 2015
from 13:30 to 14:15
at 122:026
Speaker : Igor Rogachevskii (Ben-Gurion and Nordita)
Abstract : 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.


Nordita  | Last modified 01 June 2015 23:01  |  HELP