水中结构振动时声学相似性的数值验证

Numerial investigation on acoustic similarity of fluid-loaded stiffened cylinder

以声学相似性原理为基础,用因次理论得到了在相似准数相等条件下的无因次系数,给出了模型和原型声学相似的条件。采用结构有限元耦合流体边界元方法计算水下相似加肋圆柱壳模型的流固耦合振动和声辐射。数值计算表明在相似条件下几何相似模型的壳体振动声学传递函数及其谱峰频率满足相似性,水下的模态、流固耦合振动响应以及声辐射均满足相似关系,并且与理论结果能够符合。

Based on acoustic similarity principle, dimensionless coefficients were obtained under the supposition of equal similarity numbers by using dimensional theory, and the similarity conditions between model and prototype were provided. The FEM for structure coupled with BEM for fluid were used in the computation of fluid-structure coupled vibration and acoustic radiation of an underwater stiffened cylinder. Under similar conditons, numerical calculation shows that for geometrically similar models, the acoustic transfer function and it＇ s spectral peak frequency both meet the similarity conditions, the underwater mode, response of fluid-structure coupled vibration and acoustic radiation all satisfy the similarity relations, and the results accord well with the theoretical results.