Research on a Planar Hydrophone Integrated With an Acoustic Baffle Based on Local Resonance Principle

Hydrophones are usually affected by platform structural noise when working underwater. In order to suppress the adverse impact of the low-frequency structural noise, a new acoustic baffle consisting of a locally resonant acoustic metamaterial with broadband, low-frequency and high absorption coefficients was designed. The reflection and absorption coefficients of the acoustic baffle with air backing were analyzed by the finite element method, and samples were fabricated for performance verification. A planar hydrophone integrated with the acoustic baffle was developed to reduce the adverse impact of forward reflected sound waves and backward radiated noise, and the receiving sensitivity and directivity of the baffle hydrophone were analyzed theoretically. This work investigates the potential of metamaterials in hydroacoustic applications and makes contribution to the improvement of the platform-mounted hydrophone design.