【作者】 迟凤阳；

【导师】 商德江；

【作者基本信息】 哈尔滨工程大学 ， 水声工程， 2009， 硕士

【摘要】 我国近岸海域属于富营养水域,在沿海和港湾附近地区往往有江河淡水携带大量泥沙注入,使得海水中不仅有大量的生物、非生物的存在,同时还悬浮有大量的泥沙颗粒物,这样的海水也称为混浊海水。国内海洋界曾对近海混浊海水做过大量的调查研究,但多是对于沉积、输运过程的机理研究,对于混浊水的声吸收、声散射特性的研究极为有限。然而系统、深入地研究混浊水的声吸收特性,对于声探测系统的设计、提高现有水声设备的工作性能等有重要现实意义。本文就是针对混浊水的声吸收特性进行研究的。主要有声波的衰减理论,声吸收测量的原理及方法,混浊水的组成等;同时,在实验室中搭建了一套混浊水声吸收系数测量系统,该测量系统具备比较完善地真空除气、温度控制等设施。利用蒸馏水标校测量系统等效的吸声系数,采用已知浓度的硫酸镁溶液来标校测量系统的测量精度。在此基础上,测量了不同浓度混浊水的声吸收系数,研究了温度变化对混浊水声吸收的影响,总结了混浊水声吸收系数随频率、浓度、温度等的变化规律。更多还原

【Abstract】 The sea area close to our homeland belongs to high nutritional water filed. In the neighbor field of the shores and harbors, mud and sand carried by the rivers usually pour into the sea area. There not only exist various biology and non-living things, but also exist a lot of suspended mud and sand particles in the seawater. This kind of the seawater is also called turbid seawater. The domestic ocean specialists have been doing a lot of research on the offshore turbid seawater. But their research is mainly done on the process of suspended particles’ deposition and transport. Only a little research has been done on the properties of sound absorption and sound scattering in turbid seawater. If the property of sound absorption in turbid water is investigated deeply, it will be useful to optimize the design of acoustic detection system and enhance the working performance of underwater acoustic equipments.The property of sound absorption in turbid water has been investigated in the paper. The theory of sound attenuation, the principle and method of sound absorption measurement, the composition of turbid water, etc, have been explained in detail. Meanwhile, the system to measure sound absorption in turbid water has been built up in the laboratory. There are some apparatus, such as air degassing, temperature control, etc, in the designed system. The equivalent sound absorption coefficient of the system can be calibrated by the distilled water. The accuracy of the system can be gotten by the magnesium sulfate solutions of known concentration. On that basis, the coefficient of sound absorption in turbid water of different concentration has been obtained. The temperature effect on the sound absorption in turbid water has also been investigated. The law that the coefficient of sound absorption in turbid water changes with the frequency, concentration, temperature has been summarized.更多还原