Hot Film Velocity Measurements Downstream of a Swept Backward-Facing Step

Abstract

Abstract : The purpose of this study was to determine the effects of sweep angle of the velocity field around a swept backward-facing step. Three step sweep angles were investigated: 0, 15 and 30 degrees. Velocity measurements were made using a single component hot film anemometer. Results from this study indicate the following: the flow in the recirculation region is almost perpendicular to the step, flow reattachment length decreases with increasing sweep angle, and in the reattachment region the velocity component parallel to the step face retains a finite magnitude. Coles' law of the wall and wake used to correlate the data from this study. The results indicate that upstream of the step, weak pressure gradients act on the flowfields, and downstream of reattachment of the flow recovers more rapidly as the sweep angle increases. A Baldwin-Lomax analysis on the separated profiles in the recirculation region suggest that all length scales must take into account the displacement of the shear layer from the wall. The correlation of the separated, normal and parallel, velocity profiles with the Baldwin-Lomax variables was fair.