受电弓区域是高速列车噪声重要来源，影响车内乘客乘坐舒适性以及对环境的友好性。本文通过数值仿真分析高速来流下受电弓气动噪声的特性，在现有模型的基础上对两种不同类型的杆件进行优化设计，得到某型受电弓的低噪声模型。研究主要工作如下：

首先基于计算流体力学（Computation Fluid Dynamics, CFD）与 Lighthill 声 类比理论结合的方法，通过剪切应力输运（Shear Stress Transport, SST）k-Omega 模型进行定常运算，大涡模拟（Large Eddy Simulation, LES）与 Ffows WilliamHawkings（FW-H）声学模型进行非定常流场中高速列车受电弓的气动噪声数值模拟，对受电弓非定常流场内的漩涡强度与远场噪声的指向性进行计算，分析了受电弓气动噪声的产生机理。

研究结果表明：受电弓气动噪声主要来源于其杆件表面的脉动压力，属于偶极子声源，且弓头部位、底座与绝缘子为受电弓区域最主要的噪声源。然后分析了来流速度对受电弓气动噪声的影响，结果表明：当来流速度从 300km/h 提升至 400km/h，受电弓气动噪声的最大值提升了 7.49dB；模型表面涡脱落现象随着速度的提升而明显加剧，且在受电弓的所有部位中弓头区域的涡量分布变化最为剧烈。因此确定了将抑制弓头与底座区域涡的生成与脱落作为受电弓低噪声设计的重点。 然后本文根据截面形状将受电弓各部位杆件分为圆柱与方柱两类，分别对这两种杆件进行不同优化方式的低噪声设计，比较不同模型的降噪效果对相应的降噪的原理进行了讨论。其中对圆柱杆件进行椭圆化处理并添加凹槽结构的优化设计，对方柱杆件进行圆角化处理并开贯通孔与细缝的优化设计。研究结果表明： 对比圆柱杆件，椭圆凹槽模型的气动噪声最大值从 102.18dB 降低到了 86.85dB， 最大声压级的总降幅达到 15.33dB；而开缝圆角模型的气动噪声最大值从 111.60dB 降低到了 86.02dB，相比方柱杆件最大声压级的总降幅达到 25.58dB。

最后将不同类型杆件的降噪方法运用于受电弓模型对应区域的低噪声设计， 选择弓头与底座部位杆件为低噪声设计的主要对象，对比优化前后涡量分布与受电弓气动噪声特性，得到低噪声设计后受电弓整体的远场气动噪声声压级最大值降低了 7.96dB。各部位杆件中弓头部位的声压级降低最多，在对称平面各辐射角度上平均达到 22.51dB，底座与绝缘子部位的降噪效果较弱，受电弓气动噪声明显降低，达到了良好的效果，为进一步研究高速列车受电弓气动噪声的降噪方法提供了参考。

The pantograph area is an important source of noise in high-speed trains, which affects the comfort of passengers and the friendliness to the environment. In this paper, the characteristics of the aerodynamic noise of the pantograph under high-speed flow are analyzed by numerical simulation calculation method. And a brand new low-noise model of a certain type of pantograph is obtained by optimizing two different types of rods of the origin pantograph model. The main research work is as follows:

Firstly, based on the combination of Computation Fluid Dynamics (CFD) and Lighthill acoustic analogy theory, the Shear Stress Transport (SST) k-Omega model is used for steady-state calculations. Large Eddy Simulation (LES) and Ffows WilliamHawkings (FW-H) acoustic models are used for unsteady flow field calculations. The strength of the vortex in the unsteady flow field and the directivity of the far-field noise of a simple pantograph model are calculated, and the mechanism of aerodynamic noise is also analyzed.

The numerical simulation of the aerodynamic noise of the high-speed train pantograph shows that the aerodynamic noise is mainly caused by the pulsating pressure on the surface of the pantograph rods, which causes the dipole sound source. And the panhead, base frame and insulators are the main noise sources in the pantograph area. In this paper, the influence of different incoming flow velocities on the aerodynamic noise of the pantograph is also compared and analyzed, which shows that when the incoming flow speed increased from 300km/h to 400km/h, the maximum aerodynamic noise of pantograph is increased by 7.49dB. And it is obtained that the vortex shedding phenomenon intensifies with the increase of the speed, resulting in the enhancement of the aerodynamic noise. The vorticity distribution in the panhead region changes most drastically, which confirms that it's important to suppress the generation and shedding of vortices in panhead and base frame area for the low-noise design of pantograph.

Secondly, the rods of each part of the pantograph are divided into two types: cylinder and square cylinder according to the cross-sectional shape, and different lownoise designs are carried out for them respectively. For cylindrical rod, the section shape is ovalized and groove structures are added to the surface. For square rod, its crosssectional shape is rounded, and openings and slits are added. The research results show that compared with the cylindrical rod, the maximum aerodynamic noise of the elliptical groove model is reduced from 102.18dB to 86.85dB, and the total reduction of the maximum sound pressure level is 15.33dB; the maximum sound pressure level Abstract III of the slotted fillet model is reduced from 111.60dB to 86.02dB, the total reduction of the maximum sound pressure level of the square rod is 25.58dB.

Finally, the noise reduction methods of different types of rods are applied to the low-noise design of the pantograph model. The rods at the panhead and base are selected as the main objects of low-noise design. Comparing the vorticity distribution before and after optimization and the aerodynamic noise characteristics of the pantograph, the maximum value of the far-field aerodynamic noise sound pressure level of the pantograph after the low-noise design is reduced by 7.96dB. The sound pressure level of the panhead is reduced the most among all the rods, reaching an average of 22.51dB at each radiation angle of the symmetry plane, which are reduced less at base frame and insulators. The aerodynamic noise of the pantograph is significantly reduced, which provides a reference for further research on the noise reduction method of the pantograph aerodynamic noise of high-speed trains.