高速列车风道传声特性及其优化设计

空调系统噪声是高速列车静置噪声的主要噪声源之一，改善风道传声特性是其减振降噪的关键所在。针对某高速列车阻抗复合消声风道结构，采用FE-SEA混合法，建立了风道传声特性分析模型，计算了100～3 150 Hz频率区段的风道传声特性，同时，基于声学有限元法计算了风道结构的声学模态，并据此分析了风道传声损失峰值和谷值的成因。为提高风道传声损失，分别从声学阻性和抗性优化两方面着手，对风道进行优化，包括选材、吸声包数量和位置等优化设计。计算结果表明：吸声选材优化可显著提高其传声损失，最大可达11.3 dB；吸声包数量和位置优化可提高其传声损失4.8 dB；阻抗复合优化方案最高可提高风道传声损失15.6 dB。相关结论可为高速列车空调系统减振降噪提供参考。

Acoustic Transmission Characteristics and Optimum Design of the Wind Ducts of High-speed Train

The noise generated by the air conditioning system is one of the main noise sources of the stationary interior noise of high-speed train, and the improvement of acoustic transmission characteristics of the wind ducts are vital for the reduction of vibration and noise. The acoustic transmission loss model of a typical impedance duct structure of air conditioning system is established and analyzed based on hybrid method of finite element and statistical energy analysis(FE-SEA). The transmission characteristics of the duct between the frequencies of 100-3 150 Hz are calculated. And the reasons of peak and valley in the transmission loss curve are illustrated by calculating the acoustic modes based on the acoustic FE method. Furthermore, in order to improve the acoustic transmission loss of the air duct, the acoustic resistivity and resistance are optimized, including the selection of material, the number and position of sound absorption package. The results show that the optimization of acoustic absorbing material can improve the transmission loss by about 11.3 dB, and the optimization of the quantity and position of the absorption package can improve its transmission loss by 4.8 dB. The impedance composite optimization can improve the transmission loss by 15.6 dB. The conclusions can provide a reference for vibration and noise reduction of air conditioning system in high-speed train.