Research on resonance frequency of low-frequency bender disk transducer under high pressure

Abstract Due to the low resonance frequency, the existing low-frequency bender disk transducer is difficult to resist due to high hydrostatic pressure due to its rigidity. With the introduction of the air pressure compensation technology, the transducer has the ability to dynamically balance with the increase of the external water pressure in its inner cavity, while the problem caused by large depth use is that the resonance frequency of the transducer increases with the increase of the inner cavity gas stiffness. Firstly, the equivalent circuit model of the transducer with and without air pressure compensation is analyzed, and the resonant frequency variation of the transducer is qualitatively analyzed. Then, the finite element model of air pressure compensation is established to calculate the resonant frequency of a bender disk transducer with a fixed size of acoustic radiation surface, and the variation trend of cavity height and resonant frequency of the transducer is found. Then, the physical production of the transducer is completed. Through the comparison between the test results and the simulation values, it is verified that the finite element simulation method can predict the frequency deviation phenomenon of the air pressure compensation bender disk transducer.