Wall independency and effect of initial shear-layer thickness in separated flow and heat transfer

Theoretical results are presented concerning the flow and heat transfer in laminar flow past a backstep. Computations are carried out using the stream function-vorticity forms of the elliptic partial differential equations. The effects of step size and initial boundary-layer thickness are discussed, and calculated temperature profiles and local Stanton numbers are compared with recently reported experimental data. It is shown that the size of the initial boundary layer can have opposing effects on the reattachment distance, depending on whether the Reynolds number is held constant. The influence on the average heat transfer of the flow and thermal structures in the reversed flow region is assessed by comparing the numerical solutions with the solutions for the wall-independent shear layer.