Near-field effectiveness of the sub-boundary layer vortex generators deployed in a supersonic intake

Abstract

In aircraft engines operating at high Mach numbers, it is exigent to reduce the magnitude of flow speed from supersonic to subsonic before entering the burner, to accomplish a proficient ignition. It is accomplished by a progression of oblique shocks as well as a normal shock wave in supersonic intakes. However, the advantage of shock enabled compression in intakes does not come independent but with colossal losses due to shock-boundary layer interactions, which includes intake unstart and an abrupt thickening/separation of the boundary layer. Controlling these interactions by boundary layer control using micro-vortex generators (MVGs) has gained prominence. In the present study, an attempt is made to control the interactions at the shock impact point in a Mach 2.2 mixed compression intake. Two types of MVGs; a conventional configuration and an innovative ramped-vane configuration were experimentally investigated by varying the MVG heights as 600, 400, and 200 μm. Also, the near-field effects of MVGs are quantified in terms of static pressure variation in the internal flow. It is found that the innovative MVGs of height 200 μm leads to favorable pressure drop in both the upstream and downstream region, due to enhanced flow mixing near the boundary layer.