理论和实验研究了液体粘滞系数对声低通滤波光纤水听器声压灵敏度频响特性的影响。为了更好地描述声低通滤波光纤水听器的声学特性, 在已建立的低频集中参量模型中, 引入了一个用于描述系统机械损耗的参量, 即机械声阻, 从而得到了改进后的声压传递函数表达式。仿真结果表明, 粘滞系数主要影响共振频率附近的响应, 随着粘滞系数的增加, 共振频率基本不变, 共振峰值迅速下降。利用蓖麻油粘滞系数随温度变化较大的特性, 在充油驻波罐中测试了不同温度下声低通滤波光纤水听器的声压灵敏度频响, 结果与仿真曲线基本吻合, 较好地验证了理论分析的正确性。

Effects of liquid viscosity coefficient on acoustic properties of acoustic low-pass filtering fiber-optic hydrophone are studied theoretically and experimentally. For better descriptions, the key parameter of machanical acoustic resistance which is used to describe the mechanical loss of the system, is introduced into the previous lumped parameters model. Then the improved expression of the transfer function is obtained by the circuit analysis method. Simulation results show that the liquid viscosity coefficient mainly affects the response near the resonant frequency. The resonant frequency is approximately identical and the transfer function amplitude at the resonant frequency decreases sharply, with the increasing of the liquid viscosity coefficient. Acoustic sensitivity frequency responses of different temperature are measured in the standing-wave tube filled with castor oil. The experimental results are in well agreement with the simulation results.