A novel underwater acoustic absorbing coating for low-frequency and broadband sound based on liquid-solid synergistic mechanism

Abstract

Underwater acoustic absorbing coatings are typically coated on submarine hulls to reduce the risk of being detected by hostile sonars. This paper presents a novel solid-liquid-gas multi-cavity structure for underwater sound absorption. An acoustic-structural coupling analysis is then performed on the deformed structure to explore how geometric parameters, hydrostatic pressure, metal frames, and mass-core influence sound absorption performance. The study also examines the sound absorption mechanism and the power dissipation density distribution in the solid and liquid components. Results indicate that with only 20 mm thickness, the proposed acoustic-absorbing coating shows excellent hydrostatic pressure resistance and offers outstanding low frequency and broadband acoustic absorption at a frequency range of 13 - 10,000 Hz. Meanwhile, the coating indicates strong angular adaptability for incident acoustic waves. This study offers a theoretical reference for the design and engineering application of ultra-thin, low-frequency, broadband underwater acoustic absorbing coating under hydrostatic pressure.