高灵敏度低频振速梯度水听器设计

Design of high-sensitivity low-frequency vibration velocity gradient hydrophone

目前振速梯度水听器存在灵敏度低、频带窄等缺点,限制其在工程上的应用。为解决以上问题,基于电化学换能原理,采用电极微机械加工工艺,设计了一种电化学换能振子,并制成高灵敏度、低频振速梯度水听器。所设计的电化学振子振速灵敏度达到2500 V/(m/s),较动圈振子的振速灵敏度提高了19 dB,工作频带由20 Hz~200 Hz扩展到5 Hz~400 Hz,表明其具备更高的灵敏度和更宽的工作频带。振速梯度水听器在100 Hz~400 Hz频段内进行校准,结果显示纯偏导通道x和y方向的灵敏度以及混合偏导通道的灵敏度均满足每倍频程6 dB增长规律,且分别具有偶极子指向性和四极子指向性。纯偏导通道和混合偏导通道的灵敏度和指向性的测试值与理论值基本一致。

The vibration velocity gradient hydrophone has the disadvantages of low sensitivity and narrow frequency band,which limits its application in engineering.In order to solve those problems,based on the principle of electrochemical energy exchange,an electrochemical energy exchange sensor is designed by using electrode micromachining technology,and a vibration velocity gradient hydrophone with higher sensitivity and lower frequency is fabricated.The designed electrochemical sensor has a vibration sensitivity of 2500 V/(m/s),which is 19 dB higher than that of the moving coil sensor.The operating frequency band is extended from 20 Hz~200 Hz to 5 Hz~400 Hz,indicating that it has higher sensitivity and wider operating frequency band.The vibration velocity gradient hydrophone is calibrated within the frequency range of 100 Hz to 400 Hz.The results demonstrate that both the sensitivity of the pure partial derivative channel in the x and y directions,as well as the sensitivity of the mixed partial derivative channel,adhere to a growth rate of 6 dB per frequency range while exhibiting dipole directivity and quadrupole directivity respectively.The measured values of sensitivity and directivity of pure and mixed partial derivative channels are in agreement with the theoretical values.