高速列车受电弓气动噪声频谱分析

受电弓是高速列车上主要的气动噪声源,而受电弓气动噪声又是宽频噪声,其气动噪声的声压级和频率可能达到多大的水平目前还没有定论。利用斯特劳哈尔数和圆柱绕流数值计算,依据受电弓杆件最小直径估算了其峰值计算频率。基于Lighthill声类比理论的混合方法,计算分析了某高速列车受电弓的表面偶极子声源大小及分布,并以此为基础,计算了受电弓的远场气动噪声。计算结果表明:支撑滑板、转轴是受电弓的主要气动噪声源;随列车运行速度的提高,受电弓远场气动噪声增大,最大声压级所对应的频率值增大;受电弓宽频噪声的高声压级频段持续到接近3000Hz,与车体的气动噪声相比,其高声压级持续的频段更宽。

Spectrum Analysis of Aerodynamic Noise on High-Speed Train Pantograph

Pantograph is the main aerodynamic noise source on high-speed train,however,the level of aerodynamic noise and frequency of pantograph is still not conclusive due to the fact that the pantograph aerodynamic noise is broadband noise.Using the Strouhal number and the numerical calculation of flow around the cylinder,the peak frequency is estimated according to the minimum diameter of the pantograph. Based on the Lighthill sound analogy theory,the size and distribution of surface dipole sound source of a pantograph on a high-speed train are calculated and analyzed. The calculation results demonstrate thatsupport skateboards and shaft are the main aerodynamic noise source of pantograph. With the acceleration of train speed,the aerodynamic noise of pantograph far field increases,so as the frequency value corresponding to the maximum sound pressure level.The high sound pressure level band of broadband noise continues to be near 3000 Hz. The high sound pressure level of the pantograph wide-band noise continues to be near 3000 Hz,andcompared with the aerodynamic noise of the train body,the band of high sound pressure level of the continuous frequency is wider.