Experimental Research On Sound Absorption Measuring In Turbid Water Medium

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.