NUMERICAL SIMULATION OF HEAT TRANSFER AND FLOW STRUCTURE IN 3-D TURBULENT BOUNDARY LAYER WITH IMBEDDED LONGITUDINAL VORTEX

Heat transfer characteristics and flow structure in turbulent flows through a flat plate three-dimensional turbulent boundary layer containing built-in vortex generators have been analyzed by means of the space marching Crank-Nicolson finite difference method. The method solves the "slender" flow approximation of the steady three-dimensional Navier-Stokes and energy equations. This study used the eddy diffusivity model and standard k-epsilon model to predict heat transfer and flow field in the turbulent flow with imbedded longitudinal vortex. The results show boundary layer distortion due to vortices, such as strong spanwise flow divergence and boundary layer thinning. The heat transfer and skin friction show relatively good results in comparison with experimental data. The vortex core moves slightly away from the wall and grows slowly; consequently, the vortex influences the flow over a very long distance downstream. The enhancement of the heat transfer in the vicinity of the wall is due to the increasing spanwise separation of the vortices as they develop in the streamwise direction.