Studies on effects of boundary conditions in confined turbulent flow predictions
Abstract
The differences in k epsilon model predictions of plane and axisymmetric expansion flows is investigated. The prediction of the coaxial jet for different velocity ratios of the annular to central jet is presented. The effects of inlet kinetic energy and the energy dissipation rate profiles are investigated for swirling and nonswirling flows. The effects of expansion ration and Reynolds number on the reattachment length are also presented. The results show that the inlet k and epsilon profiles have the most significant effect on the reattachment length and flow redevelopment for the case of coaxial jet of high velocity ratio. A comparison of k epsilon model predictions for the pipe expansion flow by the PHOENICS and TEACH codes reveals some discrepancies in the predicted results. TEACH prediction seems to produce unrealistic kinetic energy profiles in some regions of the flow. PHOENICS code produces a long tail in the recirculation region under certain conditions.
 Publication:

NASA STI/Recon Technical Report N
 Pub Date:
 September 1985
 Bibcode:
 1985STIN...8535371N
 Keywords:

 Axisymmetric Flow;
 Boundary Conditions;
 Boundary Layer Flow;
 Computational Fluid Dynamics;
 Computer Programs;
 Mathematical Models;
 Turbulent Flow;
 Energy Dissipation;
 Expansion;
 Inlet Flow;
 Jet Flow;
 KEpsilon Turbulence Model;
 Kinetic Energy;
 Reynolds Number;
 Swirling;
 Turbulence;
 Fluid Mechanics and Heat Transfer