基于数值耦合方法的缸体内噪声的透射分析

分析了声波在缸体内部传播时,受缸体壁的作用,在缸体内多次反射和互相干扰产生复杂声场的传递损失。先通过理论计算和有限元边界元耦合两种方法计算了理想状态下声波入射到中间介质时的透射传递损失,两种运算结果一致,从而证明了数值方法的正确性。进而对缸体内部复杂声场进行了分析,缸体内部施加单极子声源作为初始激励,建立有限元结构模型进行振动模态分析,以确定结构的振动特性,再与边界元模型耦合,连接处结构的振动响应传递给流体模型,作为流体模型的激励,计算缸体透射声波的传递损失。应用实例说明了该方法对复杂声场的分析易于实施,具有更广泛的工程适用性。

Sound Transmission Analysis through Cylindrical Shells Based on Numerical Coupled Method

An analytical study is conducted in this paper to understand the characteristic of sound transmission through an cylindrical shell within which the sound wave is reflected repeatedly and the sound field becomes very complex under the action of the cylinder wall.First,theoretical calculation and finite element-boundary element coupled method are used to calculate the transmission loss of ideal state when sound wave passes through the intermediate level.Results are consistent.That proves the correctness of numerical method.Then the analysis to the complex sound field of cylinder is carried on.For the purpose of sound transmission analysis,a single pole source is used in this study and finite element structural model is established to compute the vibration modal to determine the vibration characteristic of the structure.Then coupled with the boundary element model.The vibration response is passed to the fluid model at the junction.Result shows that the coupled method is suited for identification of complex noise sources.