A study of the second and third order closure models of turbulence for prediction of separated shear flows
Abstract
The hybrid model of the Reynoldsstress turbulence closure is tested for the computation of the flows over a step and disk. Here it is attempted to improve the redistributive action of the turbulence energy among the Reynolds stresses. By evaluating the existing models for the pressurestrain correlation, better coefficients are obtained for the prediction of separating shear flows. Furthermore, the diffusion rate of the Reynolds stresses is reevaluated adopting several algebraic correlations for the triplevelocity products. The models of Cormack et al., DalyHarlow, HanjalicLaunder, and Shir were tested for the reattaching shear flows. It was generally observed that all these algebraic models give considerably low values of the triplevelocity products. This is attributed to the fact that none of the algebraic models can take the convective effect of the triplevelocity products into account in the separating shear flows, thus resulting in much lower diffusion rate than Reynolds stresses. In order to improve the evaluation of these quantities correction factors are introduced based on the comparison with some experimental data.
 Publication:

NASA STI/Recon Technical Report N
 Pub Date:
 August 1985
 Bibcode:
 1985STIN...8534353A
 Keywords:

 Algebra;
 Closure Law;
 Computational Fluid Dynamics;
 Reynolds Stress;
 Separated Flow;
 Shear Flow;
 Turbulence Models;
 Turbulent Flow;
 Evaluation;
 Mathematical Models;
 Predictions;
 Fluid Mechanics and Heat Transfer