Jets in a supersonic crossflow are known to produce a three-dimensional bow-shock structure due to the blockage of the flow. Multiple jets in a streamwise linear array interact with both one another and the incoming supersonic flow. A parametric study was carried out to analyze the effect of microjet injection in a supersonic crossflow using flow visualization, planar, and stereoscopic velocity field measurements. The variation of the microjet orifice diameter and spacing within an array was used to study the three-dimensional nature of the flowfield. Each microjet in a supersonic crossflow generates a longitudinal counter-rotating vortex pair (CVPs). The vortex pairs remains coherent for arrays with larger spanwise separation distances between the micro-orifices. The bow shock resulting from microjet injection becomes nearly a two-dimensional structure as the spacing between the micro-orifices is reduced. The strength of the microjet-generated oblique shock is characterized in terms of wave angle and change in velocity across the shock. A comparison with previous results in a Mach 1.5 and 2 flows show that the strength of shock waves generated using microjet array scale with the momentum coefficient, C_μ. A conceptual model of the microjet arrays issuing in a supersonic crossflow is presented.
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