Natural Convection Heat Transfer in the Separated Region of a Backward-Facing Step

Abstract

An experimental investigation of natural convective flow past a backward-facing step has been conducted. Vertical plates heated with a constant heat flux are installed upstream and downstream of the step and water is used as the working fluid. The flow and temperature fields downstream of the backsteps are visualized. The results show that three-dimensional flow appears beyond a certain value of the step height H. The flow separation and the transition to turbulence are found to occur at a higher H than the above. The local heat transfer coefficients of the downstream plate are measured and it is revealed that the heat transfer rates at the vicinity of the step are increased significantly at high values of H, and become much larger than those for a fiat-plate.