Multi-fluid cavity underwater acoustic transducer

Abstract

A multi- fluid cavity underwater acoustic transducer is developed. The main structures of the transducer include inner Helmholtz resonator, Janus longitudinal vibration transducer and two outer Helmholtz resonators. The vibration of Janus transducer at low frequencies is enlarged by the inner Helmholtz resonator, and the vibration of Janus transducer at high frequencies is enlarged by the two outer Helmholtz resonators, so this kind of transducer can transmit broadband acoustic signal in water. Operation bandwidth of the multi-fluid cavity underwater acoustic transducer is usually more than two octaves. The broadband operating mechanism of the transducer is studied. The effect of some of the major structural parameters on the operation bandwidth and Helmholtz resonance frequency is studied by finite element software ANSYS. The structure size of virtual prototype is obtained. A prototype is produced based on finite element design results, the electro-acoustic performance are tested in anechoic tank. The results agree well with the simulation results. Operation bandwidth of the prototype is 500 Hz–2500 Hz, the maximum source level greater than 200 dB.