An investigation of the effects of upstream mass injection on cavity oscillations

The experimental effort attempted to determine the effect mass injection had on the amplitude of cavity pressure oscillations using varying amounts of injection and different injection patterns. The boundary layer was also traversed by a cone probe at several locations to determine the effect of mass injection on the boundary layer profiles. Finally, a computational simulation of the experimental setup was conducted. Results have shown that a more uniform injection with a higher blowing parameter produced the greatest reduction in the cavity pressure oscillations. The probe traverse measurements were successful except directly behind the injection surface. The computational simulation has shown shear layer movement but a spectrum analysis of the static pressures in the cavity indicated only random fluctuations.