数值/解析混合方法计算含复杂结构的有限长圆柱壳体声辐射

Computation of Sound Radiation from Complicated Cylindrical Shell by Using Numerical Analytical Matching Method

本文研究了含复杂内部结构的水中有限长圆柱壳体的受激振动和声辐射问题。壳体的振动方程由Donnell方程描述,内部支座结构的作用由有限元方法计算,采用数值／解析混合计算方法对具有支座结构壳体的声辐射进行预报。首先分析了数值计算中水负荷计算简化对计算壳体激励力的影响,而后讨论了内部具有支座结构的有限长壳体的声辐射特性。解析的方法有助于分析壳体产生声辐射的机理;有限元数值计算方法能够针对壳体内部不规则的结构进行计算,数值／解析混合计算方法结合了两种方法的优点,使得能够对含复杂结构的壳体振动和声辐射情况进行预报。

The vibration and sound radiation of finite cylindrical shell immersed in water with internal structure were considered. Donnell equation was used to describe the vibration of the shell and FEM (finite element method) was used for calculation of the force acted on the shell by internal structure. Firstly, the influence of fluid load on calculation of exciting force on shell was concerned, and then, the vibration and radiation characteristics of finite shell were discussed. Analytical solution is helpful for understanding the radiation mechanism, and numerical method can be used to analyze complicated structures. The numerical/analytical matching method was used to predict the sound radiation power of the shell. This matching method has advantages of these two methods and can be used to predict radiation sound level of shell with internal substructure.