High Reynolds number wedge-induced separation lengths at Mach 6

Abstract

Introduction A LTHOUGH many studies have been performed on the character of the interaction region, most of these have been limited to supersonic flows. In the majority of these studies the Mach number was varied between 2 and 4.5, with unit Reynolds number (Re) up to 98 x 10/m tested. This Mach number limitation is a result of the smallto mediumsized supersonic tunnels available for such basic research. The purpose of this Note is to present for the first time experimental data that clearly demonstrate the behavior of the separation region in high Reynolds number turbulent boundary layers at hypersonic speeds. Past works have indicated that the upstream extent of the separation zone decreases with increasing Mach numbers and Reynolds numbers, and increases with increasing ramp angle. Others' indicate the upstream movement of the separation point as the Reynolds number is increased. This disagreement may be due in part to the nature of the boundary layer flow. In this note, the reaction of the separation zone to changes in the Reynolds number from 33 to 98 x lOVm at Mach 6 will be presented.