高速列车受电弓气动噪声分析与空腔降噪研究

随着高速列车运行速度的不断提高,受电弓气动噪声也愈加严重。针对这一问题,文中采用LES大涡模拟、边界层噪声源模型和FW-H声类比法,通过建立某型号受电弓局部1:1气动噪声分析模型进行数值模拟。文中研究了受电弓各部位的气动噪声贡献量,还探究了针对较大噪声位置空腔采用射流降噪方法的降噪效果。结果表明,当网格总数为4 323万个时,数值模拟精确度满足要求。受电弓空腔上游和空腔中部绝缘子是气动噪声的主要来源。在射流降噪前后,空腔内部气动噪声均为宽频带噪声,主要能量集中在0~4 500 Hz。对250 km·h^-1行驶速度下的空腔进行主动射流降噪,距列车25 m远处的垂向监测点声压级最小值为81.65 dB,比降噪前降低了2.64 dB。

Aerodynamic Noise Analysis for High-Speed Train' s Pantograph and Study on Noise Reduction of the Cavity of Pantograph

In view of the increasing speed of high-speed trains and the increasing aerodynamic noise of the pantograph, LES large eddy simulation, boundary layer noise source model and FW-H acoustic analogy method are used to carry out numerical simulation by establishing a local 1:1 aerodynamic noise analysis model of a certain type of pantograph. The contribution of aerodynamic noise of each part of the pantograph is studied, and the noise reduction effect of the jet noise reduction method for the cavity of the larger noise position is explored. The results show that the numerical simulation accuracy is accurate when the number of grids is 43.23 million. The insulator upstream of the pantograph cavity and the middle of the cavity are the main sources of aerodynamic noise. Before and after the jet noise reduction, the internal aerodynamic noise is broadband noise, the main energy is concentrated in 0~4 500 Hz. The inclined jet noise reduction is performed on the cavity at a traveling speed of 250 km·h^-1, and the minimum sound pressure level of the vertical monitoring point 25 m away from the train is 81.65 dB, which is 2.64 dB lower than that before noise reduction.