Coupling transfer matrix method to finite element method for analyzing the acoustics of complex hollow body networks

This paper exposes a procedure to couple multiport transfer matrices to finite elements for analyzing the acoustics of automotive hollow body networks with a minimum of memory requirements and computational time. Generally, hollow body networks are made up from a series of elongated fluid partitions similar to ducts or waveguides. These fluid partitions generally contain complex elements: junctions, noise control elements, and cavities. The location and type of these elements in the network, mainly the noise control elements (e.g., sealing parts), may impact the noise inside a car. In the proposed hybrid method, the elongated fluid partitions are modeled with fluid finite elements. All complexities are modeled with two-port or multiport transfer matrices. The coupling of these matrices to finite elements is naturally done at the weak integral formulation stage of the acoustical problem. The coupling does not add any degrees of freedom to, nor modify, the original finite element matrix system. Consequently, changing locations and types of noise control elements in the hollow body network is fast and does not require rebuilding the finite element system. This enables optimizing the acoustics of a complex network on a desktop computer. The hybrid method is compared to experimental results on a tee-shaped hollow body networks. Good correlations are obtained. (C) 2011 Elsevier Ltd. All rights reserved.

本文介绍了一种将多端口传递矩阵与有限元耦合的方法，用于分析汽车空心体网络的声学特性，且具有最低的内存需求和计算时间。一般来说，空心体网络由一系列类似于管道或波导的细长流体分区组成。这些流体分区通常包含复杂的元件：连接点、噪声控制元件和腔体。这些元件在网络中的位置和类型，主要是噪声控制元件（例如密封部件），可能会影响车内的噪声。在所提出的混合方法中，细长流体分区采用流体有限元建模。所有复杂情况都采用二端口或多端口传递矩阵建模。这些矩阵与有限元的耦合在声学问题的弱积分公式化阶段自然完成。这种耦合不会给原始有限元矩阵系统增加任何自由度，也不会对其进行修改。因此，在空心体网络中改变噪声控制元件的位置和类型速度很快，且不需要重新构建有限元系统。这使得在台式计算机上优化复杂网络的声学性能成为可能。将该混合方法与三通形空心体网络的实验结果进行了比较，得到了良好的相关性。© 2011爱思唯尔有限公司。保留所有权利。