Effect of secondary fluid injection on flow through supersonic nozzle

The effect of secondary gas injection on the flow through an axisymmetric Mach 2 nozzle is studied experimentally. The experiments were conducted for a nozzle pressure ratio of 5. The secondary injection locations chosen for this study were L_s = 0.5L_d and 0.75L_d, and the secondary gas was injected at secondary pressure ratios (SPR) 0.5, 1.0, and 1.5. It is found that for injection at 0.5 L_d, the flow emanating is not deflected for all SPRs. For injection at 0.75 L_d, the flow is deflected by about 5.5⁰, 5.5⁰ and 10⁰, for SPRs 0.5, 1.0, and 1.5, respectively. These flow deflections are observed only in the plane of injection. The effect of secondary injection was not observed in the plane normal to the secondary injection.