A Study of Numerical Modeling of Heat Transfer in Wall-Adjacent Turbulent Flows

In this paper we present some of the most practical problems of convective heat transport to or from a rigid surface, the flow in the vicinity of the body is in turbulent motion. On the hand, at the solid-fluid interface itself, the no slip boundary condition ensures that turbulent velocity fluctuations vanish. But, at the wall, the diffusive transport of heat and momentum in the fluid is precisely expressible by the laws of applicable to laminar flow. Because, the turbulent shear stress, and often the turbulent heat flux, can, by continuity, increase only as the cube of the distance from the wall, there is a thin but very important sublayer immediately adjacent to the solid surface where the transport of heat and momentum is predominantly by molecular diffusion. Further from the wall, again by virtue of the cubic variation, there is a very rapid changeover to the state where turbulent transport dominates, a condition that normally prevails over the remainder of the flow. This thin sublayer and the adjacent transition region extending to the fully turbulent regime collectively we shall term the viscosity affected-sublayer (VSL); is the subject of the present paper. Furthermore, we are concerned with how one can accurately model the flow in this region in a form suitable for use in CFD software. However, the accuracy is not only criterion.