WALL-WAKES IN MODERATE ADVERSE PRESSURE GRADIENTS.

Abstract

The flow past an obstacle attached perpendiculary to a surface (wall) is postulated to possess the characteristics of boundary layer flow in the vicinity of the wall and free-wake flow away from the wall. Analytical analyses of wall-wake flows with adverse pressure gradient (without causing separation of the boundary layer) are made to obtain expressions for variations of free stream velocity and the characteristic length and velocity scales of the self preserving flow. Experiments were conducted in a wind tunnel for three arbitrary adverse pressure gradient flows. The experimental observations indicate that wall-wakes in adverse pressure gradient can be adequately described by the two-layer model proposed.