Experimental Study of Hypersonic Flow Development in a Pipe

摘要

The structure of supersonic flow in a duct has important implications in thedesign and operation of wind tunnel diffusers, inlets, and induction systems of hypersonic airbreathing engines. An investigation was conducted to elucidate the structure of the hypersonic flow developed in a circular pipe. Experiments were performed in a hypersonic gun tunnel at a free-jet Mach number of 8.30 and a Reynolds number based on the pipe diameter of 2.44 million. To visualize the flow over the pipe model, a schlieren photographic system was employed. Wall static pressure, as well as in-stream static and pitot pressure measurements at several sections in the pipe, shed some light into the physical nature of the considered flow. These preliminary measurements indicate that shocks generated in the pipe flow are primarily oblique. Measurements near the pipe axis and in wave structures presented some difficulties.