Abstract
Flow modification downstream of a backward-facing step has been tried to achieve heat transfer enhancement by introducing two kinds of devices, a triangle prism rib and electromagnetic actuators, on the step edge. The triangle prism rib attached to the side-wall corner makes the downward flow inclined and generates a circle-like fluid motion behind it. Because such kind of flow modifications work effective in reducing the flow re-circulation caused behind the step, large heat transfer recovery is obtained near the side-wall. This advantage of the triangle rib remains effective when the flap actuations are imposed. Thus, the large-scale unsteady vortex intensively reduces the flow re-circulation, the triangle rib with flap actuations attains the largest heat transfer recovery behind the step.
