有限元/边界元法求解多连通域声辐射问题

Analysis of acoustic radiation in multiply connected domain by FEM/BEM

本文用混合有限元 /边界元法求解浸没在无限流域中任意形状结构物的声辐射问题。求解多连通域声辐射问题时 ,采用有限元构建内流域和结构域 ,边界元构建外流域 ,应用流体结构域交界面法向速度连续性条件耦合声流域和结构间的相互作用。对球形结构的数值计算同其理论结果的比较表明其有效性。对环肋双层柱形结构分别对考虑和不考虑腔间进水做了计算 。

For structural-acoustic problems of arbitrarily shaped body, numerical solution is a direct approach. Mixed Finite Element Method and Boundary Element Method (FEM/BEM) is presented for predicting the acoustic radiation from an arbitrarily shaped body vibrating in an infinite fluid medium. Boundary Element Method is used to compute the added mass and damping coefficients caused by the structure vibrating in the exterior field. And the Finite Element Method is used to solve the structural dynamics and the fluid flow of the interior field. The interaction of the fluid-structure-fluid system is coupled by the interface boundary condition,i.e. the continuity of the normal velocity. Numerical result of a spherical model is compared with the theoretical result and the validity of the programme is verified. The result of a double-cylindrical structure model shows the necessity of considering the fluid effect in the inner field.