External airbag-type deepwater electrodynamic transducer

An external airbag-type electrodynamic transducer structure was proposed to solve the problems of traditional electrodynamic transducers, such as limited operating depth, failure to work for a long time, and excessive buoyancy change. The driving vibrator of the transducer was placed in the oil-filled cavity to balance the hydrostatic pressure and increase the heat dissipation channel of the coil. The external sound insulation airbag was used to eliminate the dipole's acoustic radiation mode to improve the transducer's acoustic radiation ability. This study analyzed the acoustic radiation performance of the transducer and the influencing law of operating depth on the acoustic radiation performance based on an equivalent circuit containing the acoustic parameters of the airbag. Moreover, the heat dissipation capabilities of the new and old electrodynamic transducer structures were compared through thermal simulation analysis. Then, two experimental prototypes of new and old electrodynamic transducers were fabricated. The source-level test results show that, within the core operating frequency band, the two electrodynamic transducers exhibit equivalent acoustic radiation performance. The external airbag-type electrodynamic transducer has long-time deepwater operation ability, and the buoyancy change can be controlled within an acceptable range of autonomous underwater vehicle thanks to the small airbag.