A Primary Study Of Sound Attenuation In Suspended Seawater

There is a long coastline on the east of our country, and many rivers flow to East China Sea. The river water carrys large amount of sand, which causes large areas of suspended water. The suspended water has remarkable impact on the performance of sonar, reduces the identifying ability of sonar. To improve the performance of sonar under this environment, there is a need to make a further study on the project of sound transmission in suspended water.This paper looks back international study progress on sound attenuation in suspended water and chooses the Urick model as the theory model of this paper by theory analysis and numerical simulation. Then this paper investigates the rules of coefficient of attenuation as the frequency, diameter of the particles, and volume concentration changes. At last, this paper investigates the rules of coefficient of attenuation combining true measured data of offing suspended seawater of China. The author brings forward a new method of investigating sound attenuation using satellite remote sensing image reverse data of suspended seawater on the work and offsets the disadvantage of practical measured data in continuity to a certain extent.The main conclusions of this paper are:1. The heat exchange attenuation of transmitting process due to particles and the scattering attenuation of particles can be neglected in the suspended seawater. Viscous attenuation of particles is the dominant factor of sound attenuation on near sea when the volume concentration of the particles reaches to a certainty.2. While the density of the particles is 2650 kg /m 3(Corresponding to the instance of quartz particles), the viscous attenuation of particles exceeds the attenuation of seawater itself when the volume concentration of the particles is more than 0.1 kg /m 3. While the density of the particles is 1450 kg /m 3(Corresponding to the instance of clay particles), the viscous attenuation of particles exceeds the attenuation of seawater itself when the volume concentration of the particles is more than 1 kg /m 3.Under this circumstance, there is a need to include the sound attenuation due to suspended particles.