Acoustic Research Laboratory, National University of Singapore, Singapore 119227.
J Acoust Soc Am. 2013 Oct;134(4):2710-8. doi: 10.1121/1.4819120.
A pressure compensated metal diaphragm based fiber laser hydrophone configuration that can provide good sensitivity, large bandwidth, and sea state zero noise floor is proposed in this paper. A simplified theoretical model of the proposed sensor configuration is developed in which the acoustic elements of the sensor configuration are modeled using a four-pole acoustic transfer matrix and the structural elements are modeled as second order single degree of freedom elements. This model is then used to optimize the design parameters of the sensor system to achieve the performance objectives. An axisymmetric finite element analysis of the sensor configuration is also carried out to validate the results from the simplified theoretical model. Prototype sensors were fabricated and hydrostatic testing in a pressure vessel validated the static pressure compensation performance of the sensor. Frequency dependent sensitivity of the sensor system was measured through acoustic testing in a water tank. The prototype sensor gave a flat frequency response up to 5 kHz and experimental results compared well with theoretical predictions. The sensor has an acceleration rejection figure on the order of 0 dB ref 1 m/s(2) Pa and the pressure compensation approach worked reasonably well up to a hydrostatic pressures equivalent to a depth of 50 m.
本文提出了一种基于压力补偿金属膜片的光纤水听器结构，该结构具有良好的灵敏度、大带宽和零海态噪声基底。本文建立了简化的理论模型，在该模型中，传感器结构的声学元件采用四端口声学传递矩阵建模，结构元件采用二阶单自由度元件建模。然后，利用该模型对传感器系统的设计参数进行优化，以实现性能目标。还对传感器结构进行了轴对称有限元分析，以验证简化理论模型的结果。制作了原型传感器，并在压力容器中进行了静水压力测试，验证了传感器的静态压力补偿性能。通过在水箱中的声学测试测量了传感器系统的频率相关灵敏度。原型传感器在 5 kHz 以下的频率响应平坦，实验结果与理论预测吻合较好。该传感器的加速度抑制比约为 0 dB ref 1 m/s(2) Pa，压力补偿方法在相当于 50 米水深的静水压力下效果良好。
