Turbulent Separation Analysis Ahead of a Step

Abstract

The general nature of the flow separation of a turbulent boundary layer ahead of an inward-projecting normal step is shown to be well predicted by a rotational flow analysis (frozen vorticity theory). The basis of this theory—that in the immediate vicinity of major wall contour changes the diffusive effects of viscosity and turbulence on the vorticity may be neglected and the flow field thus made amenable to rather simple analysis—is demonstrated and its application, via numerical iterative calculation, to prediction of the separation flow occurrence ahead of a step in terms of a given turbulent boundary layer is indicated. Good experimental verification of the predictions is found.