A treatment of wall boundaries for (kepsilon) turbulence modelling within an integral (finite element) formulation
Abstract
A treatment of wall boundaries uses the twoequation kepsilon turbulence model where epsilon, the dissipation rate of the turbulence kinetic energy (k), is an equivalent length scale variable. Being selfdeveloping and internal, a turbulence model with a global length scale as a field variable is much preferred over the arbitrary local setting of a length scale. The present formulation clearly demonstrates the normal and shear stress contributions and the role of any given analytical wall function in determining the near wall shear wall stress. The wall function gives the shear velocity directly which then permits the setting of k and epsilon at the boundary in the turbulence model closure. The method is tested and appropriate boundary conditions are generated for the complex system of flow past a backward facing step where a recirculation zone is induced including flow separation, point of reattachment, and reverse flow along a side wall.
 Publication:

Finite Element Flow Analysis
 Pub Date:
 1982
 Bibcode:
 1982fefa.proc..227T
 Keywords:

 Boundary Layer Flow;
 Finite Element Method;
 KEpsilon Turbulence Model;
 Recirculative Fluid Flow;
 Turbulent Flow;
 Wall Flow;
 Backward Facing Steps;
 Boundary Conditions;
 Computational Fluid Dynamics;
 Flow Velocity;
 Kinetic Energy;
 Shear Stress;
 Turbulent Mixing;
 Two Dimensional Boundary Layer;
 Fluid Mechanics and Heat Transfer