NUMERICAL-STUDIES OF HEAT-TRANSFER CHARACTERISTICS BY USING JET DISCHARGE AT DOWNSTREAM OF A BACKWARD-FACING STEP

This study presents the numerical predictions of the fluid flow and he at transfer characteristics for a backward-facing step by discharging a jet perpendicularly to the main flow. The turbulent governing equati ons are solved by a control-volume-based finite-difference method with power-law scheme and the well known K - epsilon model and its associa te wall function to describe the turbulent behavior. The interesting p arameters include entrance Reynolds number (Re-b), dimensionless jet l ocation (X-j/H) and the ratio of jet velocity (U-j/U-0) with channel e xpansion ratio ER = 1.67. The predicted attachment point is in good ag reement with the experiment. It is found that the optimum position is at X-j/H = 2.1 (X-j: location of jet measured from the step position, H: the step height).