车用消声器声固耦合的研究与分析

发布时间：2018-06-21 11:52

  本文选题：消声器 + 消声性能　； 参考：《山东大学》2014年硕士论文

【摘要】：随着我国汽车保有量的逐年上涨,噪声污染问题变得越来越严重,人们对噪声问题的关注也越来越高。内燃机噪声是道路噪声污染的主要来源,对内燃机的减振降噪一直是学术研究的热点。现在,对内燃机排气噪声的控制主要有两方面的措施,一是从噪声源的传播机理入手,对噪声源本身进行控制。二是在排气口处安装排气消声器,此方法简单有效,所以成为国内外应用最广泛的方法。在消声器设计阶段,根据设计数据对消声器进行消声性能的预测,这对设计阶段的优化指导具有重要的意义。研究表明,实际工况下消声器的检测性能与设计阶段仿真模拟和理论计算数据之间存在有一定的偏差。相关学者研究认为,这些偏差可能与消声器声固耦合、实际检测环境、数据测量误差以及数据处理误差有关,其中声固耦合的影响占主要部分。 实际中对消声器消声性能的计算一般都是从声学基本方程出发,将消声器的壁面做刚性处理,并且不考虑介质的流速。但是这样计算的结果一般都与实际情况有明显差别,如工况下测得的消声器的消声性能与理论模拟之间存在较大差异。当需要精确计算消声性能而考虑声固耦合作用的影响时,壁面振动将作为声学方程的一个边界条件,这增加了微分方程求解的难度。对于声固耦合问题的求解,一般采用有限元方法,将壁面振动作为边界激励条件,将边界振动转化为声压波动,用边界振动矩阵修正声学刚度矩阵,将节点振动与节点声压联系起来。求解声固耦合的影响。 文章开始从理论基本公式出发,详细推导了考虑声固耦合作用下的消声器声学性能的计算,并利用商用声学计算软件进行对比计算。研究了结构、壁厚、材料以及约束等不同因子对声固耦合的影响。并且从模态的概念出发,分析了结构振动及内部声压变化的关系；指出结构振动和内部声压的变化共同作用改变消声器的消声特性。并得出在某些频段上是不可忽略声固耦合影响的,在消声器设计阶段应进行声固耦合的分析计算,并给出了改善声固耦合的建议。
[Abstract]:With the increasing of automobile ownership in China, the problem of noise pollution becomes more and more serious, and people pay more and more attention to the problem of noise. The noise of internal combustion engine is the main source of road noise pollution. At present, there are two main measures to control the exhaust noise of internal combustion engine. One is to control the noise source itself from the mechanism of the noise source. The second is to install exhaust muffler at the exhaust port. This method is simple and effective, so it has become the most widely used method at home and abroad. In the stage of muffler design, the muffler performance is predicted according to the design data, which is of great significance to the optimization guidance of the design stage. The results show that there is a certain deviation between the performance of muffler and the data of simulation and theoretical calculation in the design stage. It is considered that these deviations may be related to acousto-solid coupling of mufflers, actual detection environment, data measurement errors and data processing errors, among which the influence of acousto-solid coupling is the main part. In practice, the muffler's noise performance is usually calculated from the basic acoustic equation, the silencer's wall is treated rigidly, and the velocity of the medium is not taken into account. However, the calculated results are generally different from the actual situation, such as the muffler performance measured under working conditions and theoretical simulation. When the influence of acousto-solid coupling is taken into account in the accurate calculation of acoustic performance, wall vibration will be regarded as a boundary condition for acoustic equations, which increases the difficulty of solving differential equations. For the solution of acousto-solid coupling problem, the finite element method is generally used, the wall vibration is taken as the boundary excitation condition, the boundary vibration is transformed into the sound pressure fluctuation, and the acoustic stiffness matrix is modified by the boundary vibration matrix. The nodal vibration is associated with the nodal sound pressure. The influence of acousto-solid coupling is solved. Starting from the basic theoretical formula, this paper deduces the calculation of acoustic performance of muffler considering acoustic-solid coupling in detail, and compares the calculation with commercial acoustics calculation software. The effects of different factors, such as structure, wall thickness, material and confinement, on acousto-solid coupling are studied. Based on the concept of mode, the relationship between structural vibration and internal sound pressure change is analyzed, and it is pointed out that the joint action of structural vibration and internal sound pressure changes the muffler's noise characteristics. It is concluded that the influence of acousto-solid coupling should not be ignored in some frequency bands, and the analysis and calculation of acousto-solid coupling should be carried out in the design stage of muffler, and some suggestions for improving the acousto-solid coupling are given.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U467.493;TB535

【参考文献】

中国期刊全文数据库 前10条

1 刘忠族,孙玉东,吴有生;管道流固耦合振动及声传播的研究现状及展望[J];船舶力学;2001年02期

2 罗虹;王伟戈;邓兆祥;褚志刚;陶丽芳;;汽车排气消声器内部流场和声场数值分析[J];重庆大学学报(自然科学版);2006年08期

3 王雪仁;季振林;;快速多极子声学边界元法及其研究应用[J];哈尔滨工程大学学报;2007年07期

4 赵荣宝,陈秉聪,程悦荪;车内噪声与结构振动偶合研究的现状与进展[J];吉林工业大学学报;1987年02期

5 张乃龙;杨文通;费仁元;;基于ANSYS的抗性消声器性能仿真分析[J];计算机仿真;2006年08期

6 吴国荣,钟伟芳,吴永东,梁以德;应用分形有限元方法于外域声场计算[J];力学与实践;2004年05期

7 吴兴世;;航空流体—结构耦合系统动态分析的动态子结构方法[J];民用飞机设计与研究;1996年02期

8 黎苏,葛蕴珊,黎志勤,张旭;抗性消声器的三维声学边界元模型及其应用[J];内燃机学报;1992年02期

9 蔡超,宫镇,诸圣国;存在气流时轴对称抗性消声器传递损失的有限元法求解[J];汽车工程;1994年05期

10 马天飞,林逸,闵海涛,秦民,张建伟;轻型客车NVH特性的刚弹耦合、声固耦合仿真研究[J];汽车工程;2005年01期

中国博士学位论文全文数据库 前2条

1 方建华;基于CFD的工程机械抗性消声器设计与性能分析[D];山东大学;2009年

2 李艳华;考虑流固耦合的管路系统振动噪声及特性研究[D];哈尔滨工程大学;2011年

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