含悬浮泥沙颗粒水介质的声吸收实验研究

Experimental Investigation on Measuring Sound Absorption in the Water Medium Containing Suspended Sediment Particles

混浊海水的声吸收系数对水声探测设备工作性能的影响很大。设计并制造了一套声吸收实验测量系统，利用混响法测量了频率为20～60kHz混浊海水的声吸收系数。当混浊海水中悬浮泥沙颗粒的浓度小于110mg／L时，混浊海水的声吸收系数与纯净海水的声吸收系数差别较小，混浊海水中引起吸收的主要成份是电解质硫酸镁；当悬浮泥沙颗粒的浓度超过140mg／L时，悬浮泥沙颗粒引起的声吸收已非常明显，混浊海水的声吸收系数最大为纯净海水声吸收系数的2倍。实验结果表明，混浊海水的声吸收系数近似与悬浮泥沙颗粒的浓度成正比，与频率的平方成正比。该研究成果可对混浊海水中声纳探测系统设计、声纳探测距离确定以及声纳性能的评估提供一定的参考。

The coefficient of sound absorption in turbid seawater has a significant effect on the working performance of underwater acoustic detection equipment. A system of measuring sound absorption was designed and built up in laboratory, by which the coefficient of sound absortion in turbid seawater having relaxation frequency of magnesium sulfate between 20 - 60 kHz was measured based on the reverberation method. When the concentration of suspended sediment particles is less than 110 mg/L, coefficient different between the turbid seawater and the clear seawater is very little, sound absorption in turbid seawater is mainly caused by the electrolyte, magnesium sulfate; if the concentration of suspended sediment particles is above 140 mg/L, the sound absorption caused by suspended sediment particles is remarkable, which maximum coefficient is twice as that in clear seawater. The experimented results show that the coefficient of sound absorption in turbid seawater is approximately proportional to the concentration of suspended sediment particles and square of the frequency. The results are useful for designing the sonar detection system, determining the sonar＇s detection range and estimating the sonar＇s performance in turbid seawater.