Vibration and sound radiation of an acoustic black hole plate immersed in heavy fluid

Abstract

Vibrational acoustic black holes (ABHs) have shown great promise for reducing structural vibrations and sound radiation in light fluids. However, it is still unknown whether the acoustic black hole (ABH) effect can be materialized in heavy fluids. This paper discusses this issue by developing a semi-analytical model on a simply supported ABH plate that vibrates and radiates sound into water. The proposed model is validated by finite element models and used to investigate the vibration and sound radiation properties of the ABH plate in different frequency ranges. The results show that the ABH effect can be systematically manifested in heavy fluids, as reflected by a significant increase in structural damping and a decrease in vibration and sound radiation. Numerical analysis of the radiation damping and mass loading effects shows that the radiation damping has little effect on the vibration reduction of the water-loaded plate. However, the mass loading effect mitigates the low-frequency drawback of conventional ABH structures in air, resulting in a broadband reduction in structural vibration and sound radiation from the water-loaded ABH plate.