Turbulent Boundary-Layer Separation in Front of a Forward-Facing Step

Abstract

A review of experiments concerned with the description of the steady flowfield produced by the separation of a turbulent boundary layer ahead of a forward-facing step is presented. The Mach number is restricted to the supersonic range and only two-dimensional flows are investigated. The dependence of the induced pressure field at the wall on Reynolds number, Mach number, and step height is considered. It is shown that the pressure rise in the separation region expressed in normalized form is independent of Mach number and Reynolds number and that the scale for the separation phenomena is the boundary-layer thickness. In addition, it was found that the plateau pressure rise is independent of Reynolds number for the turbulent regime and that the induced side force increases linearly with Mach number.