低频高灵敏度中性浮力式MEMS矢量水听器

由中北大学研制的微机电系统(MEMS)矢量水听器具有小型化、低频性能好、灵敏度高、指向性好、价格低等特点,但目前该水听器对该低频水声信号的低频探测能力不够,所以进一步提高其灵敏度对水听器的未来的发展至关重要。在声学研究的基础上,提出了中性浮力微结构并确定其参数,该结构加大了外力的有效作用面积,从而提高水听器的灵敏度,采用ANSYS有限元对水听器性能进行仿真,为了验证其可靠性,在驻波场测试水听器的性能。结果表明,该水听器的灵敏度-175dB,频响范围为20~500 Hz,满足对远距离船舶辐射噪声的探测要求,灵敏度响应曲线的起伏在±1.5dB以内,具有良好的"8"字型指向性,凹点深度为48.8dB。

Central buoyant MEMS vector hydrophone of low-frequency and high sensitivity

The MEMS bionic vector hydrophone developed by North University of China has advantages of low frequency, miniaturization, high sensitivity, etc. But the sensitivity of the hydrophone is still low for detecting the week acoustic signals. How to enhance the sensitivity is a critical problem to the future developments. So a type of central buoyant microstructure is proposed, expecting to improve the sensitivity. And based on the acoustic research, the parameters of the central buoyant sphere is finally determined. The influences of the central buoyant microstructure on the sensitivity and the frequency band are analyzed by static analysis and fluid-structure interaction respectively. In order to verify the feasibility and performance, the hydrophone is tested in the standing wave field and in the real environment. Results show that the sensitivity of the hydrophone is -175 dB, the frequency ranges from 20 Hz to 500 Hz, which satisfies the requirement of detecting the ship radiation noise over a long distance, and the fluctuation range of frequency response curve is 1.5 dB. The directivity pattern of 8-shape is good(48.8 dB).