Control of Pressure Oscillations Induced by Supersonic Cavity Flow
Wang Xiansheng, Dangguo Yang, Jun Liu, Zhou Fangqi
Abstract
A control method is developed to suppress pressure oscillations induced by supersonic cavity flow using high-speed upstream injection. The injection is generated with a large blowing coefficient through a channel, which guides the airflow blowing off in the leading edge of the cavity. Wind tunnel experiments are performed to validate the method with Mach 1.8 and 2.0 flows over a length-to-depth 6 cavity. Six dynamic pressure transducers are used to characterize the cavity oscillation. A remarkable suppression of pressure fluctuation is realized in the controlled cavity flow. The overall sound pressure level can be reduced by larger than 10 dB in both configurations. The most remarkable reduction in pressure fluctuation occurs near the cavity trailing edge, wherein flow-induced oscillation is strongest. Almost no cavity tones are observed near the cavity trailing edge under control. Further, the control method is proven effective and stable over time. The feedback loop is interrupted in the controlled cavity flow with a weak impact of shear vortices on the cavity aft wall. The control method may be a practical and potential candidate for use in engineering applications because it does not need additional gas supply in the control system.