摘 要

内燃机和柴油机排气管的排气噪声是工业噪声的重要来源，而使用合适的排气消声器可以有效降低其排气噪声。汽车消声器作为降低汽车噪声的主要方式，其研究受到世界各国的广泛关注，在工业噪声污染的控制中举足轻重。

对一个消声系统，我们可以将其分为多个消声单元，每一个消声单元都可以用声压和体积速度两个状态量来描述其两侧状态，对于一个给定的消声单元，其一侧的状态量可以决定另一侧的状态量，相当于一个个四端子参数，在数值上用传递矩阵表示。

本文借助声学运动方程、连续性方程和四端子网络法，推倒出消声单元串并联线路，建立了简单扩张式消声器与并联共振式消声器模型，得出其声场传递矩阵，最终得到消声单元的插入损失。

关键词：消声器 传递矩阵 四端子网络

Abstract

The exhaust noise of internal combustion engine and diesel engine exhaust pipe is an important source of industrial noise, and the use of appropriate exhaust muffler can effectively reduce the exhaust noise. As the main way to reduce the noise of automobile, automobile muffler is widely concerned by all the countries in the world, and it is very important in the control of industrial noise pollution.

Of a sound system, we can be divided into a plurality of anechoic units, each muffler element can sound pressure and volume velocity of two state variables to describe the state of both sides of the, for a given anechoic units, which is arranged on one side of the state can be decided on the other side of the state, equivalent to one of the four terminal parameter, the numerical with transfer matrix representation.

In this paper, by means of acoustic equation, continuous equation and four terminal network, push out muffler element on parallel lines, the simple expansion type silencer and parallel resonant muffler model is established that the sound field transfer matrix, finally get the insertion loss of the muffler element.

Key Words:Muffler;Transmission matrix;Four-pole network

目录

摘要.....................................................................................................................................................................Ⅰ

Abstract...............................................................................................................................................................Ⅱ

第一章 绪论.........................................................................................................................................................1

1.1汽车消声器研究的背景和意义................................................................................................................ 1

1.1.1噪声的危害..........................................................................................................................................1

1.1.2对噪声的控制......................................................................................................................................2

1.1.3研究排气消声器的意义......................................................................................................................3

1.2课题研究国内外现状.................................................................................................................................4

1.3本文的主要工作.....................................................................................................................................9

第二章 消声器的设计.......................................................................................................................................10

2.1消声器基本参数的确定...........................................................................................................................10

2.2消声器详细参数的确定...........................................................................................................................13

第三章 排气消声器有限元法的数学模型......................................................................................................15

3.1抗性消声器四端子参数及性能评价...................................................................................15

3.1.1 消声器四端子参数.......................................................................................................................15

3.1.2 消声器评价指标...........................................................................................................................17

3.2有限元法数学模型的建立.......................................................................................................................20

3.2.1 数学模型的建立.............................................................................................................................21

3.2.2 消声器变分问题.................................................................................................................23

第四章 消声器ANSYS计算结果及分析........................................................................................26

4.1 有限元模型建立..........................................................................................................................26

4.1.1 单元和插值函数的选取.................................................................................................................26

4.1.2 有限元模型建立...........................................................................................................................27

4.2 简单扩张式消声器计算......................................................................................................................31

4.3 复杂结构消声器的分析..........................................................................................................................40

总结.....................................................................................................................................................................45

参考文献........................................................................................................................................................... 46

致谢.....................................................................................................................................................................48

第一章 绪论

1.1汽车消声器研究的背景和意义

随着生活水平的提高，人们迫切需要一个安静的工作和学习环境。据统计，反映环境污染的投诉，对噪声的投诉逐年增加，已经从1991年的2.78万个增加到1995年的3.90万，增加了大约40%；反映噪声污染的投诉占25%，环境污染投诉的比例从1991年的25%提高到1995年的35.6%，五年之间增加了百分之十。是各种污染投诉中比例最高的一位。为了控制噪声污染，在中国，自70年代末相继颁布实施《工矿企业噪声卫生标准》、《城市区域环境噪声标准》、《工矿企业厂界噪声标准》和《中华人民共和国环境噪声污染防治条例》以及其他相关法律法规。噪声的产生机理研究及噪声控制和环境噪声污染的控制已成为世界上一个重要的研究课题。

相关图片展示：