MIXED CONVECTION HEAT-TRANSFER IN HORIZONTAL RECTANGULAR DUCTS WITH WALL TRANSPIRATION EFFECTS

A detailed numerical study was carried out to examine the effects of w all transpiration on laminar mixed convection flow and heat transfer i n the entrance region of horizontal rectangular ducts. The vorticity-v elocity method was employed in the formulation. Both thermal boundary conditions of uniform heat flux (UHF) and uniform wall temperature (UW T) were considered. Predicted results are presented for air flow over a wide range of governing parameters. In this work, the wall Reynolds number Re, are varied from -2 (suction) to 4 (injection) with Rayleigh numbers Ra ranging from 0 to 2 x 10(5) for aspect ratios gamma = 0.2, 0.5, 1, 2 and 5. The predicted results show that either wall injectio n or wall suction has a considerable impact on the flow structure and heat transfer performance. In addition, the correlating equations for the average fRe and Nu are presented. (C) 1997 Elsevier Science Ltd.