摘要
随着高速列车的运行速度不断增加,其产生的气动噪声呈现明显多声源特征,高速运动效应显著,四极子声源比例增加,对列车远场噪声的影响不容忽视。根据混合CAA方法,基于涡声理论和Lighthill声比拟方法,分析400 km/h受电弓结构周围流场与气动噪声、远场声传播特性,研究四极子声源对其声辐射的影响。结果表明:受电弓结构高速运动在近壁面产生的复杂涡运动是主要气动噪声源,涡结构主要集中在头部、底架和绝缘子处。受电弓高速运动产生的高湍流区域主要发生在主杆附近,导致体四极子声源加强,该区域部件表面流动分离,产生较强的湍流。四极子声源最大强度约为偶极子声源的0.4倍,其声场能量转化效率比偶极子声源低。受电弓近场最大总声压级为136 dB,远场声辐射沿不同方向的主频位于同一频带,频谱整体呈现多峰特征。400 km/h高速列车受电弓产生的气动噪声中,四极子声源能量占比达到38.3%。
The escalating speeds of high speed trains have led to the emergence of obvious multi-source features of aerodynamic noise generated by trains,characterized by pronounced high speed motion effects and an elevated presence of quadrupole sound sources.The consequential impact is considerable on the far-field noise generated by trains.Leveraging the hybrid CAA methodology,based on the vortex sound theory and Lighthill acoustic analogy method,this study analyzed the flow field,aerodynamic noise,and far-field acoustic propagation properties adjacent to the pantograph structure at a speed of 400 km/h.The influence exerted by quadrupole sound sources on acoustic radiation was studied.The results reveal that the complex vortex movement near the wall surface,induced by the rapid movement of pantograph structure constitutes the primary aerodynamic noise source.These vortex structures predominantly cluster around the head,underframe,and insulator.The high turbulence areas stemming from the high speed movement of the pantograph mainly occur in the vicinity of the main poles,contributing to an amplification of the body’s quadrupole sound source.Intense turbulence arises from surface flow separation on the components in this area.The maximum intensity of the quadrupole sound source reaches approximately 0.4 times that of the dipole sound source,with a lower sound field energy conversion efficiency compared to the dipole source.The total near-field sound pressure level of the pantograph peaks at 136 dB,and the main frequencies of acoustic radiation in the far-field,across different directions,converge within the same frequency band.The spectral profile as a whole reflects multi-peak characteristics.The quadrupole source energy contributes to 38.3%of the overall aerodynamic noise stemming from the pantograph of a high speed train running at 400 km/h.
作者
蔡陈之
肖军
李晏良
詹晏
CAI Chenzhi;XIAO Jun;LI Yanliang;ZHAN Yan(School of Civil Engineering,Central South University,Changsha Hunan 410075,China;China Academy of Railway Sciences Corporation Limited,Beijing 100081,China)
出处
《中国铁路》
北大核心
2024年第6期7-16,共10页
China Railway
基金
国家自然科学基金资助项目(52378546)。
关键词
气动噪声
低频声场
四极子声源
声传播
数值仿真
高速列车
受电弓
aerodynamic noise
low-frequency sound field
quadrupole sound source
acoustic propagation
numerical simulation
high speed train
pantograph
