Abstract: The pressure test experiments for the inner-outer flow interaction area are conducted at CARDC’s 0.5m hypersonic wind tunnel. The experiments are conducted at the condition of uniform and non-uniform incoming flow.Using non-uniform inner nozzle, the pressure of aircraft’s afterbody expansion surface and horizontal wing surface can be measured by simulating aircraft nozzle’s non-uniform incoming flow. High speed schlieren is used to observe flow field structure of plume’s interaction areas, and the influence rules of non-uniform incoming flow on aircrafe nozzle’s afterbody expansion surface and horizontal surface pressure distribution can be got under different conditions. The experiment result shows that nozzle’s non-uniform incoming flow has significant influence on aircraft’s wall surface pressure distribution and flow field structure. The non-uniform character of nozzle’s incoming flow can not be ignored in air breathing hypersonic vehicle plume simulation. From experiment result, the pressure of non-uniform plume’s core area is obviously higher than that of uniform plume; while outside the core area, non-uniform plume has a slightly smaller action area than uniform plume, the interaction area and intensity of non-uniform plume and outflow is also smaller than uniform plume. Uniform plume has distinct expansion waves in nozzle’s exit area, the expansion angles of interaction shock wave and shear layer are larger than non-uniform plume.

Key words: air breathing vehicle, hypersonic, non-uniform nozzle plume, inner-outer flow interaction, pressure test