Biblio

Acoustic tomography experiments for ocean observation require low-frequency, broadband, high power, small size underwater acoustic transducer, but there are contradictions between the performance of the transducer, therefore a longitudinal-bending fluid-cavity coupled broadband underwater acoustic transducer is presented. The difference between the transducer and the traditional JH transducer is that the opening position of the Helmholtz resonant cavity is arranged between the radiation cover plate and the cylindrical cavity. Based on the optimization results of the finite element software ANSYS produced a transducer test prototype. The test results show that the simulation results and experimental results are basically consistent, and the transmitting voltage response can reach 136dB, the transmitting voltage response fluctuation shall no more than 6dB through the range of 700-1200Hz in the horizontal direction, verified the longitudinal-bending mode and the fluid-cavity mode of the transducer are well coupled, and the transducer is an ideal low-frequency, broadband, high power, small size underwater acoustic transducer.

This paper designed a longitudinal bending coupled piezoelectric transducer. The transducer is composed of a rear metal block, a longitudinally polarized piezoelectric ceramic piece and a slotted round front cover. The longitudinal vibration of the piezoelectric oscillators drive the front cover to generate bending vibration to widen the operating frequency band while reducing the fluctuation of transmission voltage response. In this paper, the design method of this multimode coupled transducer is given, and the method is verified by numerical simulation. The results show that the analytical theory and numerical simulation results have good consistency. This longitudinal-flexural coupled vibration transducer widens the bandwidth while preserving the emission voltage response.