Noise suppression of high-speed cavity treated with leading and trailing edge spoilers

High-speed cavity flow and the induced noise have been continuously investigated in the aerospace industry. They may not only influence the performance of instruments inside the cavity, but also cause fatigue damage to the structures, which threaten the safety of aircraft. Therefore, cavity noise suppression is practically important. In this work, the leading edge sawtooth, the leading edge cylinder, and the trailing edge contouring are employed to suppress high-speed cavity noise at Mach numbers of 2.0, 2.5, 3.0, 3.5, and 4.0. Wind tunnel tests were performed to study the influence of the control parameters associated with these suppression methods. The results show that the leading edge sawtooth and cylinder are able to effectively suppress cavity noise at Ma = 2.0, 2.5, but prove ineffective at Ma = 3.0, 3.5, and 4.0, suggesting that the critical Mach number locates between 2.5 and 3.0. Above the critical Mach number, cavity noise would increase. In comparison, the noise suppression effect of the trailing edge contouring is relatively minor, and it shows a monotone decreasing trend as Mach number increases from 2.0 to 4.0.