浅海中圆柱壳的声辐射特性分析

Research on the acoustical radiation characteristics of cylindrical shells in ashallow sea

根据声学边界元理论,本文在考虑海面和吸声海底的声反射作用基础上,对格林函数进行修正,建立波导域声辐射模型,并分析了浅海中圆柱壳的声辐射特性。研究发现吸声和刚性海底边界条件下圆柱壳的辐射声场有明显差别;可采用波导中点源格林函数预测圆柱壳的声辐射特性。结果表明边界反射作用随着圆柱壳离开海面或海底而减弱,随着场点离开圆柱壳而增强;且水深方向上声压呈周期性波动,其周期规律与海底边界类型无关。本文用声学点源的辐射叠加原理解释研究现象的产生机理,可为工程应用提供理论参考。

According to the acoustical boundary element theory on acoustics and considering the sound reflection effect of the sea surface and sound-absorbing seabed, the Green Function was modified, and an acoustical radiation model in the waveguide domain was established. In addition, the acoustical radiation properties of a cylindrical shell in the shallow sea was analyzed. It is found that the sound absorption is apparently different from the radiative sound field of the cylindrical shell under the conditions of a rigid seafloor. The Green Function on the point source in the parallel waveguide space can be used to forecast the acoustical radiation of the cylindrical shell. When a cylindrical shell leaves the sea surface or sea-floor ,the boundary reflection effect will weaken ; when a field point leaves the cylindrical shell, the effect will strength-en. In the direction of the water, s depth, the sound pressure fluctuates periodically, its periodic law is irrelevant to the type of seabed boundary. The radiation superposition principle of the acoustical point source is used to explain the forma-tion theory of such a phenomenon, which can provide a theoretical reference for engineering applications.