Leading-edge separations and cross-flow shocks on delta wings

Recently published numerical solutions of the Euler equations have shown the existence of very strong cross-flow shocks in the attached flow on the lee surface of uncambered delta wings. These shocks occur in flight conditions where previous work has shown that the lee-surface flow would be expected to show a leading-edge separation with a pair of contrarotating vortices inboard. This paper presents the results of an experimental study of the flow over one of the wings (mounted on a small body) for which numerical solutions were obtained. At the test Mach numbers where strong shocks occur in the numerical solutions, the experimental flow shows a complete leading-edge separation with a pressure distribution very different from that calculated. The significance of these results in relation to the change from leading-edge separation to attached flow around the leading edge with increasing Mach number is discussed.