Qin Deng, Li Tian, Dai Zhiyuan, Zhang Jiye
State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu, 610031, China.
Environ Sci Pollut Res Int. 2022 Dec;29(57):86580-86594. doi: 10.1007/s11356-022-21215-9. Epub 2022 Jun 9.
It is still difficult to conduct numerical calculation of the aerodynamic noise of full-scale, long-marshalling, high-speed trains. Based on the Lighthill acoustic analogy theory, the aerodynamic sound source of the high-speed train is equivalent to countless micro-vibrating sound sources. An acoustic radiation model of the dipole sound source of high-speed trains is established, and a method to predict the aerodynamic noise in the far field of long-marshalling high-speed trains is proposed. By this method, combined with numerical simulation technology, the flow field, noise source, and far-field noise characteristics of high-speed trains with different marshalling numbers are studied. The improved delayed detached eddy simulation method is used for flow field calculation, to obtain aerodynamic noise source information regarding the surface of high-speed trains. The numerical calculation method is verified by wind tunnel testing. The results show that the flow field and noise source characteristics of high-speed trains with different marshalling numbers are similar. The greater the length of the train body, the longer the trailing distance of the train wake, and the stronger of a surface noise source the tail car becomes. The spatial distribution characteristics of aerodynamic noise in the far field of high-speed trains do not change significantly with the length of the train body, but the magnitude of the sound pressure level will increase with the increase in length of the train body. The middle car body parts of high-speed trains with different marshalling numbers have similar noise distributions and sound pressure levels. Based on the noise calculation results of the 3-marshalling high-speed train, the far-field noise of the 5-marshalling and 8-marshalling train models is predicted and found to be in good agreement with the far-field noise of the actual train model. The differences in average sound pressure level are 1.01 dBA and 1.74 dBA, respectively.
对全尺寸、长编组、高速列车的气动噪声进行数值计算仍然很困难。基于莱特希尔声学类比理论，高速列车的气动声源等效于无数个微振动声源。建立了高速列车偶极子声源的声辐射模型，提出了一种预测长编组高速列车远场气动噪声的方法。通过该方法，结合数值模拟技术，研究了不同编组数量高速列车的流场、噪声源及远场噪声特性。采用改进的延迟分离涡模拟方法进行流场计算，以获取高速列车表面的气动噪声源信息。通过风洞试验验证了该数值计算方法。结果表明，不同编组数量高速列车的流场和噪声源特性相似。列车车身长度越大，列车尾流的拖尾距离越长，尾车表面噪声源越强。高速列车远场气动噪声的空间分布特性不会随列车车身长度发生显著变化，但声压级大小会随着列车车身长度的增加而增大。不同编组数量高速列车的中间车身部分具有相似的噪声分布和声压级。基于3编组高速列车的噪声计算结果，对5编组和8编组列车模型的远场噪声进行了预测，发现与实际列车模型的远场噪声吻合良好。平均声压级差异分别为1.01 dBA和1.74 dBA。
