Mitigation of Cavity Noise with Aeroacoustically Excited Surface Panels

This study has employed a unique concept to mitigate the deep cavity aeroacoustics at low Mach number through the utilization of localized surface compliance. The key idea is to absorb the energy from the aeroacoustic processes of a self-sustained feedback loop in cavity flow, which generates a tonal noise. A thorough examination of this concept has been carried out using high-fidelity, two-dimensional direct aeroacoustic simulation at a Reynolds number of 4×10^4 and a Mach number of 0.09. To achieve noise suppression, an elastic panel with a natural frequency matching the characteristic frequency of the cavity aeroacoustic feedback loop has been strategically introduced to modify the process. As a result, there is a 15 dB reduction in cavity noise, along with a 20% decrease in the cavity drag. The proposed concept successfully suppresses cavity noise and drag while maintaining the basic problem geometry, which is crucial for practical applications.