【作者】 周星达；

【导师】 文学洙；

【作者基本信息】 延边大学 ， 机械设计及理论， 2011， 硕士

【摘要】 噪声污染是世界上公认的三大污染之一。消声器经常被用来消减各种噪声。消声器主要分为抗性消声器、阻性消声器以及复合型消声器。本文主要研究的是抗性消声器。消声器的声学性能中,最主要的参数是传递损失。传递损失之所以常被用来评价消声器的声学性能,主要是因为它直观反映了消声器的消声性能,消减了多少分贝的噪声。另外只要有消声器的几何参数,传递损失就可以获得,它是消声器本身固有的一种特性,不受声源的阻抗和辐射阻抗的影响,只与消声器的构造有关。本文的主要研究内容是抗性消声器中简单扩张腔的扩张比、进出口位置、插入管、穿孔板以及其它形状的扩张腔等参数对于传递损失的影响。通过声学有限元分析软件Sysnoise的有限元分析方法得出各参数对传递损失的影响规律。声模态作为扩张腔的一个重要的声学参数,本文利用改变扩张腔的各种几何参数探究了声模态与传递损失的内在关系。从而得出一套对于给定目标频率下实现理想消声效果的方法。本文采用有限元法和三点法结合的方式,首先在Catia中实现建模,然后利用有限元前处理软件Hypermesh进行网格划分再导入到Sysnoise进行有限元分析,最后得出数据并在Matlab中进行数据处理。由于有限元方法十分耗时,所以本文中提出了利用二元模型分析代替三元模型的方法,首先利用二元模型得出各参数对传递损失的规律,然后用三元模型进行分析验证。对二元模型和三元模型得出的传递损失进行比较,得出两者之间的差异。更多还原

【Abstract】 Noise pollution is one of the world’s three major sources of pollution, A silencer is often used to reduce kinds of noise. Silencers are conventionally classified as dissipative and reflective and hybrid silencer. This paper studies the reflective silencers.Transmission loss is the most important parameter which frequently used to evaluate acoustic performance of a silencer. That is because TL is able to visually reflect the attenuation performance of a silencer. Besides TL is the inherent characteristic of a silencer, it is able to be predicted very conveniently from the known physical parameters of silencer and are not be influenced by source impedance and the radiation impedance, there is only relationship with configure of silencer.Main contents of this article is the impact of expansion ratio, location of inlet/outlet, extended inlet/outlet, perforated panels, shape of expansion chamber on transmission loss of a simple expansion chamber in the reflective silencer. Utilize the FEM software Sysnoise to obtain the relationships between each parameters and transmission loss. Acoustic mode as an important acoustical parameter of expansion chamber. This thesis utilize the geometric size variables of the expansion chambers to explain the internal relations between transmission loss and acoustic mode. After that derive a method which is able to achieve a satisfied value of transmission loss in a target frequence.This thesis adopts the way which combines the finite element method and three-points method. The model is generated in Catia first ofall. After that utilize the preprocess software Hypermesh for meshing. Then import the model to the Sysnoise proceeds finite element analysis. Finally data processing is done in the Matlab. Because of the FEM is very time consuming, so this thesis presents replace three-dimensional model by two-dimensional model. First utilize analysis of the two-dimensional model to obtain the relationships between parameters and transmission loss then proved it by analysis of three-dimensional model. Compare the results form two kinds of model and derive the differences between them.更多还原