高速列车受电弓导流罩气动噪声特性分析

Analysis on Aerodynamic Noise Characteristics of Pantograph Fairing of High-speed Train

针对高速列车受电弓区域气动噪声问题,采用大涡模拟和FW-H声学模型重点对列车在250 km/h、350 km/h运行时受电弓导流罩气动噪声进行数值模拟,建立了车体+受电弓导流罩的计算模型,分析导流罩表面偶极子声源分布和气动噪声频谱特性。研究结果表明:350 km/h下导流罩表面气动噪声整体大于250 km/h;两种速度下导流罩表面偶极子声源分布规律在频域表现一致:在高频阶段声压级明显低于低频阶段,5000 Hz下最大声压级仅为20 Hz下的40%;导流罩表面最大声压级都诱发于凹腔与后引导面的过渡处,20 Hz下分别可达136 dB、143 dB。此外,导流罩近场和远场气动噪声频谱曲线相似,均是一种宽频噪声,且能量主要集中在150~950 Hz,对后续更高速级列车受电弓导流罩降噪结构设计和隔声材料的选取有一定实际参考意义。

For the aerodynamic noise of high-speed train pantograph region,large eddy simulation(LES)and FW-H acoustic model were used to simulate the aerodynamic noise of pantograph fairing at speeds of 250 km/h and 350 km/h,and the aerodynamic noise calculation model of train+pantograph fairing was established to analyze the dipole sound source distribution and aerodynamic noise spectrum characteristics of the pantograph fairing.The results show that the aerodynamic noise on the fairing surface is overall larger than 250 km/h at 350 km/h.The distribution of the dipole sound source on the surface of the fairing at the two speeds is consistent in the frequency domain:the sound pressure level at the high frequency is obviously lower than that at the low frequency,and the maximum sound pressure level at 5000 Hz is only 40%of that at 20 Hz;The loudest pressure levels on the surface of the fairing are induced at the transition between the concave cavity and the rear guide surface,reaching 136 dB and 143 dB respectively at 20 Hz.In addition,the near-field and far-field aerodynamic noise spectrum curves of the fairing are similar,both of which are broadband noise,and the energy is mainly concentrated in the range of 150-950 Hz,which has certain practical reference significance for the structural design of the pantograph fairing and the selection of sound insulation materials for the subsequent higher-speed trains.