高速列车风道消声器传声特性

为了抑制空调系统对高速列车车内噪声的影响，在风道内设置阻抗复合消声器，量化分析传声特性是高速列车低噪声设计的重要内容. 基于有限元-统计能量分析（FE-SEA）混合法建立某高速列车风道消声器传声特性分析模型，对80~3 150 Hz频率区段的风道消声器传声特性进行预测计算. 采用声学有限元法建立风道消声器声学模态分析模型，针对传递损失的峰值和谷值所在的频率区段，计算风道消声器声学模态，解释传递损失峰/谷值的成因. 从提升声学性能的角度，结合工程实际情况，对风道消声器进行设计方案优选. 结果表明：风道消声器具有良好的降噪作用，声学模态振型特性是传递损失峰/谷值的成因；消声器阻性特性对传递损失的影响最大，通过吸声选材优选可以最大提高传递损失18.0 dB；消声器抗性特性影响相对较小，通过吸声包数量和位置的优选可以最大提高传递损失4.1 dB；考虑阻抗复合优选方案，最高可以提高风道消声器传递损失18.6 dB.

Sound transmission characteristics of silencer in wind ducts of high-speed train

A typical impedance silencer was installed in the ducts in order to inhibit the effect of air conditioning system on interior noise. The quantitative analysis of its acoustic transmission characteristics is an important part of noise reduction design for high-speed trains. The acoustic transmission model of a typical impedance silencer structure in the duct of air conditioning system was established and analyzed based on hybrid method of finite element and statistical energy analysis (FE-SEA). The transmission characteristics of the silencer between the frequencies of 80?3 150 Hz were predicted and calculated. The mechanics of peaks and valleys in the transmission loss curve were explained by calculating the acoustic modes based on the acoustic finite element method. The design projects of the silencer were optimally selected from the perspective of the acoustic performance and the actual situation of the project. Results show that the silencer in the air duct can effectively reduce noise, and its acoustic mode shape characteristics are the cause of its transmission loss peak/valley. The silencer resistive characteristics have a dominant effect on its acoustic transmission loss, and the optimal selection of acoustic absorbing material can improve the transmission loss up to about 18 dB. The resistance characteristics have relatively less effect on its transmission loss, and the optimal selection of the quantity and position of the absorption packages can improve its transmission loss by 4.1 dB. The impedance composite optimal selection can increase the transmission loss by 18.6 dB.