水下复杂壳体的声学相似性研究

Study of acoustical similitude of a submerged complex shell

采用有限元和球函数相结合的方法,建立水下复杂壳体———两端带半球壳的弹性圆柱壳的振动、耦合振动和声辐射方程,运用方程分析法,导出水下复杂壳体的振动、耦合振动和声辐射的相似关系,根据建立的相似关系实现对壳体的振动响应和声辐射的预报.运用大型有限元软件ANSYS对具有相似关系的模型和原型的振动响应和声场进行数值分析,算例表明,该方法切实可行并且为预报水下大型复杂结构体的振动响应和耦合声场提供了一种简洁、实用的研究方法.

The equations of vibration, coupled vibration and sound radiation of a cylindrical shell with hemispherical cap on the end are derived by using the finite element method (FEM) and the spherical function extension method. The similitude conditions and relations of the submerged complex shell are derived by using the similitude theory. According to these similitude conditions and relationships, the vibration response and sound radiation of a submerged large-scale and complex shell can be accurately predicted by a simple similitude model. The similitude relationships of vibration response and sound radiation between prototype and model are analyzed using the finite element software ANSYS. The numerical results are given for verification. Also provided is a study method for predicting the vibration response and coupled sound field of a large-scale and complex structure.