Experimental Studies on Micro-Vortex Generator Controlled Shock/Boundary-Layer Interactions in Mach 2.2 Intake

To have an efficient combustion, the aircraft engine intakes operating at supersonic and hypersonic speeds necessarily decelerate the flow to subsonic level before entering the combustor, which is achieved by a combination of oblique and normal shock waves in the intake-isolator, and thus the high-speed intakes are called the mixed-compression intakes. The advantages of shock-enabled compression, however, does not come standalone rather associated with colossal losses due to shock and boundary layer interactions (SBLIs). The repercussions in the flow due to these interactions may include; intake unstart, abrupt thickening, separation of the boundary layer, unsteady shock oscillations, etc. Therefore, the SBLIs must be controlled to minimize the losses. Control of these interactions by manipulating the boundary layer using micro-vortex generators (MVGs) has gained prominence. In this study, a new ramped-vane MVG configuration, deployed near the shock impact point in the Mach 2.2 mixed-compression intake at varied contraction ratios, has been experimentally investigated. Plain intake and the intake controlled with conventional MVGs are also investigated for comparison. The heights of all the MVGs were varied as; 600 mu m, 400 mu m and 200 mu m. The ramped-vane MVGs of height 200 mu m are found to be the most efficient in causing a favorable pressure drop at the locations; near-upstream (x = 0.48 L) and near-downstream (x = 0.7 L) of the MVGs. The maximum reductions in static pressures about 11% at the intake contraction ratio of 1.20 at x = 0.48 L, and about 24% at the contraction ratio of 1.23 at x = 0.7 L, are achieved. The Schlieren pictures clearly demonstrate the effectiveness of all the tested ramped-vane MVGs (particularly 200 mu m MVGs) in weakening the waves and reducing the separation length.