摘 要
随着城市机动车辆的大幅增加和汽车工业的迅速发展,城市道路交通变得越来越拥挤,道路噪声污染成为影响人们日常生活的严重问题。据资料显示,城市环境噪声的百分之八十以上是来源于机动车辆,机动车辆已成为环境噪声的最大污染源。它严重地污染着城市环境,影响着人们的生活、工作和健康,所以噪声的控制,不仅关系到乘坐舒适性,而且还关系到环境保护。在发动机实际工作情况下, 建立排气系统的流动和声学数学模型, 通过数值模拟技术结合必要的测试验证手段设计消声系统的性能, 已成为发达国家开发研究消声器的基本手段。
通过查阅相关资料及实习调研在了解汽车综合催化净化消声器工作原理的基础上，对其性能进行研究，结合实际问题与需要，确定汽车综合催化净化消声器设计的整体方案，再逐个确定汽车综合催化净化消声器各个模块的方案。
关键词：催化净化；消声器；方案设计
Abstract
With the rapid increase of urban motor vehicles and the rapid development of the automobile industry, urban road traffic has become increasingly crowded, road noise pollution has become a serious problem affecting people's daily lives. According to statistics, more than 80 percent of urban environmental noise is derived from motor vehicles, motor vehicles have become the largest source of environmental noise. It is a serious pollution of the urban environment, affecting people's lives, work and health, so the noise control, not only related to ride comfort, but also related to environmental protection. Under the actual working condition of the engine, the flow and acoustic mathematical model of the exhaust system is established. Through the numerical simulation technology combined with the necessary test verification method, the performance of the muffler system has become the basic method for the developed and developed muffler.
Through the access to relevant information and practice research in the understanding of the overall principle of automotive catalytic purification muffler on the basis of its performance research, combined with practical problems and needs to determine the comprehensive design of automotive integrated silencer design of the overall program, and then one by one to determine the comprehensive catalytic purification Muffler of the various modules of the program.
Key words: catalytic purification; muffler; program design
目录
摘 要 - 1 -
Abstract - 2 -
1 绪论 - 4 -
1.1 论文研究的背景及意义 - 4 -
1.2 排气噪声的产生和成分 - 6 -
1.3 排气汽车综合式净化消声器的基本类型 - 8 -
1.4 汽车综合式净化消声器发展状况 - 9 -
1.5 此次毕业设计的主要研究内容 - 11 -
2 排气噪声的理论基础 - 12 -
2.1 基本声学理论知识 - 12 -
2.1.1 声压、声功率、声强【22】 - 12 -
2.1.2 声级 - 13 -
2.2 汽车综合式净化消声器消声性能评价指标 - 14 -
2.2.1 声学评价指标 - 14 -
2.2.2 空气动力学性能[23] - 14 -
2.2.3 结构性能 - 15 -
2.3声波波动方程 - 15 -
2.3.1 声波连续方程 - 15 -
2.3.2 声波运动方程 - 17 -
2.3.3 声波物态方程 - 17 -
2.3.4 声波波动方程 - 17 -
3 对单节扩张腔式汽车综合式净化消声器的分析 - 18 -
3.1 用传递矩阵法对汽车综合式净化消声器进行分析 - 18 -
3.1.1扩张比m的影响 - 19 -
3.1.2扩张腔长度L的影响 - 20 -
3.2用有限元法分析对简单汽车综合式净化消声器进行分析 - 21 -
3.2.1 扩张比m的影响 - 21 -
3.2.2扩张腔长度L的影响 - 24 -
3.3传递矩阵法与有限元法结果比较 - 26 -
3.4 出口管长度的影响 - 28 -
3.5内插管对传递损失的影响 - 30 -
3.6出口管偏置对传递损失的影响 - 33 -
3.7扩张腔腔数对传递损失的影响 - 36 -
3.8扩张腔长度分配的影响 - 38 -
4 汽车综合式净化消声器设计 - 42 -
4.1 汽车综合式净化消声器尺寸确定 - 42 -
4.1.1 WP7发动机参数表 - 42 -
4.1.2 汽车综合式净化消声器结构参数选择 - 43 -
4.2 三维模型建立 - 45 -
4.2.1 UG软件介绍 - 45 -
4.2.2建立的模型 - 45 -
4.3网格划分 - 47 -
4.3.1 ANSYS软件介绍 - 47 -
4.3.2 有限元模型 - 47 -
4.4传递损失计算 - 48 -
4.4.1 LMS Virtual.Lab 软件介绍 - 48 -
4.4.2 传递损失计算过程[27] - 48 -
4.4.3 结果分析 - 50 -
结 论 - 54 -
参考文献 - 55 -
致 谢 - 57 -
