Application of Broad Bandwidth to Mosaic Transducer

To realize low-frequency acoustic emission of small caliber underwater unmanned vehicle(UUV), further reduce the volume and mass proportion of a transducer in the UUV, and widen available frequency band of the transducer, a kind of thin-walled mosaic cylindrical transducer for the UUV was designed. Considering the limitation of the UUV on the transducer’s size and mass, the influence of height parameter of the mosaic circular ring on the electroacoustic performance of the transducer was analyzed by combination of the theoretical formula with the finite element software ANSYS. The reasonable design of the ring height can realize the coupling of the radial breathing vibration modal of the circular ring and the bending vibration modal in height direction to widen the frequency band. Thin wall design was adopted to reduce the mass and space occupancy. The vibration form and acoustic performance of the transducer in the frequency band below resonant frequency were analyzed through modal analysis. According to the simulated optimized results, a prototype of the transducer was fabricated. Tests show that in the operating frequency band from 5.5 to 33 kHz, the in-band transmitting voltage response fluctuates between 4 dB and +4 dB approximately, which is basically consistent with the simulation results. The in-band sound source level is greater than 173 dB, while in the lower frequency band from 500 Hz to 1 kHz the sound source level is higher than 144 dB, indicating a certain low-frequency acoustic emission performance. This work may provide a reference for realizing low-frequency and wide-band acoustic emission of small caliber UUV transducer.