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1、摘要噪声水平已成为衡量柴油机质量和性能的重要指标之一。排气噪声在柴油机整机噪声中占重要比例，安装性能良好的排气消声器是控制排气噪声的有效途径，消声器的设计方法主要有声传递矩阵法和有限元法。目前声传递矩阵法的使用范围仍限于一维平面波传播，无法考虑高次模式波效应。由于实际的排气消声器一般具有复杂的结构，其内部的声波本质上是三维的，这时应采用精确的二维（或三维）理论来进行分析，本文利用有限元分析软件ANSYS的声学分析模块对扩张式抗性消声器进行声学分析，并且取得了以下研究成果。本文讨论了运用ANSYS分析软件对抗性消声器性能进行二维有限元计算的方法，建立了消声器内部声学有限元方程的数学模型，推导了消
2、声器插入损失和传递损失的计算公式。在此基础上使用精度较高的声学单元FLUID29和FLUID129作为建模单元，在静态条件下建立了两种类型消声器的有限元模型，分别为简单消声器和复杂并联内插管双室扩张式消声器，由于简单消声器的有限元分析已比较完善，本文重点研究复杂并联内插管双室扩张式消声器的ANSYS分析，得出消声器内部声压级分布图，然后利用声传递矩阵的理论对两种类型的消声器进行了直接模拟和间接模拟，计算出了消声器的四端网络参数、插入损失和传递损失。计算结果和试验结果进行比较，取得比较一致的良好结果。从而表明ANSYS有限元分析软件计算消声器声学性能方便可行。本文的研究内容，总结了消声器理论、有
3、限元理论与计算、ANSYS软件应用等。并且对许多关键性问题，如有限元单元网格的划分、有限元模型的建立、软件后处理的数据分析技巧与注意事项等进行了探讨。因此本文为以后消声器的性能预测、计算提供了重要的理论参考和工程实例。关键词：消声器，排气噪声，ANSYS有限元，四端网络40Simulation and Analysis of Reactive Muffler Based on ANSYS SoftwareSpeciality: Mechanical Manufacture and AutomationName: Yang JiangkunSupervisor: Associate Prof.
4、Zhu CongyunAbstractThe noise level of diesel engine has become one of the important indicators on evaluation of its quality and performances. Exhaust noise is a large proportion in the overall noise of diesel engine, and the effective method of its control is the application of muffler with good per
5、formances. The important method in the design of mufflers is Four-pole network and FEM. Now the transfer matrix method is still limited in the one-dimensional plane wave, and can not consider high-wave effect. Owing to the actual muffler with complex structure, its internal sound waves are three-dim
6、ensional, now accurate two-dimensional (or three) should be used to analysis. In this paper, using ANSYS analysis software module, expansion-resistant muffler is analysis and gets the following results.In this paper, the performance of reactive muffler is calculated by the 2D FEM (Finite Element met
7、hod) with the ANSYS. The mathematical model of inner acoustic equation is established and the calculation formulas of TL (transmission loss) and IL (insertion loss) of muffler are deduced. On this basis, the FE model of two kinds of mufflers are built under static condition, with highly-precise acou
8、stic element FLUID29 and FLUID129.I design two mufflers, respectively simple and matrix. Owing to the simple mufflers analysis has been fairly completed, I analysis especially the complex muffler and get the internal level figure. Using acoustic transmission matrix, the muffler is simulated directly
9、 and indirectly and the parameter of four-terminal network, TL and IL are calculated. In the end, comparing simulation results with experiment results, it shows that calculated values coincide measured values. The simulation method is proved to be correct. The analysis software of ANSYS is expedient
10、.In the paper, muffler theory, FEM theory, ANSYS application are included. Some important factors such as FE mesh demarcation, establishment of FEM model and so on are discussed. So theory and project example of the performance prediction of muffler are provided.Key Word: Muffler, Exhaust noise, ANS
11、YS FE, Four-pole network目录1. 绪论 41.1引言 41.1.1噪声的危害 41.1.2对噪声的控制 51.2 课题研究国内外现状 61.3 课题的工作和目标 92排气消声器有限元法的数学模型 10 2.1 抗性消声器的四端参数及消声器的性能评价 10 2.1.1 消声器的四端参数 10 2.1.2 消声器的评价指标 12 2.2 有限元法数学模型的建立 15 2.2.1 数学模型的建立 16 2.2.2 消声器变分问题的推导 17 2.3 本章小结 193. 消声器的ANSYS有限元计算结果及分析 21 3.1 有限元计算模型的建立 21 3.1.1 单元和插值函数
12、的选取 21 3.1.2 有限元模型的建立 22 3.2 简单扩张式消声器的计算 25 3.2.1 简单扩张式消声器消声量的计算与分析 25 3.2.2 简单扩张式消声器插入损失的直接模拟 29 3.2.3 简单扩张式消声器内部声场分析 30 3.3 复杂结构消声器的分析 31 3.4 本章小结 334. 消声器的设计 345. 总结和展望 365.1 课题研究结论 365.2 课题展望 36参考文献 37致谢 391绪论1.1 引言噪声是工业社会带来的副产品，它是一种物理污染，具有即时性，生源发声就形成污染，生源停止发声，污染随之消失，噪声能量在空中消散，因此，噪声没有污染物，不会积累，也无法再利用。噪声污染问题已成为当代世界性的问题，它同水污染、大气污染一起被列为世界三大公
