Effect of Flow-Induced Surface Vibration on Deep Cavity Aeroacoustics

This study examines an elastic panel flush-mounted on the bottom wall of a deep cavity, under the subsonic flow condition of Mach number 0.09, as a passive approach to the tonal noise abatement. The interaction between acoustically excited cavity modes and an elastic panel installed on the cavity bottom wall is investigated using direct aeroacoustics simulation. The panel is carefully designed to maintain the natural frequency of the panel vibration in compliance with the flow frequency. Two different materials, steel and rubber, are selected for the panel design to ascertain the effect of material on the panel response to the standing cavity modes to leverage the reduction of tonal noise emissions. Numerical findings have substantiated the marked improvement in noise suppression and coefficient of pressure. Furthermore, based on a comparative analysis, the panel with elastomeric properties has shown the best potential for the tonal noise reduction.