高速列车受电弓弓头的降噪研究
Study on the Noise Reduction of High-Speed Train Pantograph Head

随着高速列车的速度提升，受电弓区域产生的气动噪声快速增强，其中弓头杆件周围漩涡引起的气动噪声最为强烈。本文首先将单弓受电弓的弓头简化为有限长方柱，并针对方柱进行了一系列低噪声设计，通过大涡模拟与FW-H声学传播方程对不同方案在高速来流下产生的流场特性和远场气动噪声特性进行了分析，获得方柱远场噪声的指向性。通过对方柱添加不同半径的圆角，得到当圆角半径为20 mm时远场气动噪声最大可以降低16.8 dB；在此基础上通过对方柱进行贯通开缝，发现宽10 mm的开缝使方柱远场气动噪声进一步降低约12.8 dB。对方柱进行截面形状优化并在此基础上进行贯通开缝，能够起到明显的降噪效果，本文研究可以为受电弓的低噪声设计提供理论支撑。
The aerodynamic noise in pantograph area increases quickly with the increase of the speed of the high-speed train, and when vortex shedding behind the rectangular cross-section panhead, it caus-es the strongest aerodynamic noise. In this paper, the panhead is simplified by a square cylinder and its far-field noise under the high-speed flow was calculated based on the Large Eddy Simulation and Ffowcs Williams/Hawkings equation. By analyzing the directivity of far-field noise and the characteristics of the flow field, a low-noise designed model is carried out. The square cylinder is preliminarily optimized by adding different radii of fillets, which causes the maximum sound pres-sure level of the far-field noise generated by the square bar is maximum reduced by 16.8 dB when the fillet radius is 20 mm, and the effect of slotting on the aerodynamic noise is further studied. It shows that with the through slits of different widths, when the width is 10 mm the maximum sound pressure level is further more reduced by 12.8 dB. In this paper, the design of optimizing the sec-tion shape and slitting has a good effect on reducing the aerodynamic noise generated by square cylinder is proved, and it provides a theoretical support for further studies on the reduction of the aerodynamic noise of the pantograph.