Pressure measurements on a slender rhombic cone at incidence at Mach numbers from 0.4 to 1.1

Abstract

Pressures have been measured on a wing in the form ofa rhombic cone at two cross-sections and along a single generator. The wing had an aspect ratio of one and a leading-edge angle of 60°. Measurements were made at M = 0.4, 0.6, 0.82, 0.9, 1.0 and 1.1, at angles of incidence up to 20° and at a Reynolds number of 6 million, based on model length. At the lowest Mach number the tests were repeated at higher Reynolds number. The measured pressure distributions are typical of flow with leading-edge vortices. Two different types of suction peaks were observed and associated, on indirect evidence, with the state of the boundary layer at secondary separation. Within each type, increasing Mach number reduced the magnitude of the peak suction, but had little effect on its spanwise location. At transonic and high subsonic speeds an increase in incidence above 8° changed the shape of the suction peak from the type associated with a turbulent secondary separation to that associated with a laminar one.