| Abstract: | Based on the energy method,the underwater resonance frequency equation and electrical admittance curve of the slotted piezoelectric ring are derived.By establishing the equivalent circuit of slotted piezoelectric ring in low-frequency receiving condition,the lowfrequency open circuit voltage sensitivity of slotted piezoelectric ring is deduced.Compared the low-frequency receiving sensitivity of the slotted piezoelectric ring and the complete ring,the thought to design the deep ocean hydrophone is presented,which combines the slotted piezoelectric ring and the free flooded structure.By establishing finite element simulation model of free flooded slotted piezoelectric ring,the relationship between ring structure parameters and low-frequency open circuit voltage sensitivity are discussed.Through the simulation and optimization,the deep-sea slotted piezoelectric ring hydrophone with the resonance frequency of 600 Hz is fabricated.The acoustic and pressure tests results indicated that the low-frequency open circuit voltage sensitivity of free flooded slotted piezoelectric ring hydrophone in work bandwidth 100-300 Hz is-193.2 dB and the least value is-197.9 dB with the-4.7 dB fluctuation.Hydrostatic pressure resistance of 30 Mpa is obtained.Compared with the same structure size free flooded piezoelectric ring hydrophone,the low-frequency open circuit voltage sensitivity of slotted piezoelectric ring hydrophone raised 20 dB.The results verify the practicability of deep ocean hydrophone presented here with free flooded slotted piezoelectric ring structure. |
