Carrying the mass flux terms exactly in the first and second moment equations of compressible turbulence
Abstract
In compressible turbulence models, it is assumed that the Favremean velocities are suitable approximations to the Reynoldsmean velocities in order to close unknown terms. This neglects, in the mean momentum and energy equations, the contribution to the stress and work terms by the mean of the fluctuating Favre velocity, a quantity proportional to the turbulent mass flux. As the stress and work terms do not introduce any new unknown correlations requiring closure in either kepsilon or Reynolds stress closures and because the exact form of the terms can, with little additional work, be carried there is no need to make any modeling assumptions. In the Reynolds stress equations the viscous terms appear naturally in Reynolds variables while the problem is posed in Favre variables. In the process of splitting the viscous terms into the viscous transport terms, carried in Favre variables, and the dissipation terms, carried in Reynolds variables, important contributions from the mass flux appear. The accurate accounting of these terms is important for any consistent near wall modeling and the retention of the mass flux terms is important in complex compressible turbulent flows.
 Publication:

Final Report Institute for Computer Applications in Science and Engineering
 Pub Date:
 November 1993
 Bibcode:
 1993icas.reptR....R
 Keywords:

 Compressible Flow;
 KEpsilon Turbulence Model;
 Mass Flow Rate;
 NavierStokes Equation;
 Reynolds Equation;
 Reynolds Stress;
 Turbulent Flow;
 Viscous Flow;
 Kinetic Energy;
 Turbulence;
 Turbulent Boundary Layer;
 Viscosity;
 Fluid Mechanics and Heat Transfer