Numerical Solution of Laminar Flow and Heat Transfer over a Flat Plate in a Nonuniform Stream.(Dept.M)

The laminar flow and heat transfer over an isothermal flat plate in a free stream with nonuniform velocity have been analysed, fully implicit numerical method (with a hybrid representation for the convective term normal to the streamwise direction) is used for solving the governing equations. Two practical cases are considered. In the first case, a flat plate is located in the laminar wake of an upstream plate. In the second case, a flat plate 18 inserted in the laminar shear layer joining a uniform stream and a quiescent fluid. The dependence of the boundary-layer and heat transfer on the lateral and the downstream shifts of the plate have been investigated. It was found that the nonuniformity of the free stream velocity causes reductions in both the wall shear stress and heat transfer relative to the corresponding values for uniform free stream. These relative reductions decrease with increasing downstream distance along the plate in the upper half of the wake. In the lower half of the wake, these Zeductions increase with distance along the plate. It was also found that the minimum values for drag and overall heat transfer rate at a certain streamwise location correspond to a slight downward shift of the plate from the wake centreline. In the case of shear layer, the relative reductions in the wall shear and heat transfer are more pronounced in the low velocity region. These reductions decrease with increasing downstream distance along the plate. It was found that both the drag and overall heat transfer rate decrease continuously with downstream shift of the plate.