计及接触网空气动力的高速弓网动态受流特性研究

Study on Characteristics of Dynamic Current Collection of High-speed Pantograph-catenary Considering Aerodynamics of Catenary

环境风作用在接触网上的空气动力主要表现为2种形式,一种是线索在平均风下表现出的空气阻尼特性;另一种是在脉动风作用下的外界激励。本文研究这2种空气动力表现形式对弓网受流的影响,分别推导了作用在接触网上的空气阻尼和脉动风气动载荷,并基于模态叠加法在弓网动力学方程中添加空气动力项进行修正。首先通过CFD（Computational Fluid Dynamics）绕流仿真计算了接触线和承力索的气动力系数,通过仿真求解表明：作用在接触线上的空气阻尼很小,且大多为正阻尼,在不导致刮弓事故的情况下不会对弓网受流产生较大危害。然后,基于AR模型和接触网结构特性通过反演Davenport顺向风速谱和Panosfsky垂向风速谱,建立了具有时间和空间相关的接触网脉动风场,通过求解分析了脉动风风速、攻角对弓网间接触压力的影响。结果表明：强脉动风场对弓网受流影响十分显著,脉动风激励主要影响接触压力的高频区域,在研究过程中不宜对接触压力进行滤波处理,风速的增加会导致接触压力谱幅值的整体增大;风速一定时,风攻角是影响受流的重要因素,流风越偏于水平方向,越有利于弓网受流,在本文所采用的京津城际铁路算例中,0～20°是对受流最有利的理想风攻角。本文从理论推导角度修正了计及接触网空气动力的弓网动力学方程,可为进一步研究接触网风振提供借鉴。仿真结论可为接触网防风设计提供参考。

The aerodynamics of the environmental wind acting on the catenary can be divided into two main forms, including air damping characteristics of catenary wires under average wind, and external stimulation un- der fluctuating wind. In this paper, in order to study the influence of the two kinds of the aerodynamics on the pantograph-catenary current collection, the air damping and the aerodynamic loads of fluctuating wind acting on the catenary were deduced respectively. Then the pantograph-catenary dynamic equation was adjusted by adding the aerodynamic term based on modal superposition method. The aerodynamics parameters of the con- tact wire and messenger wire were calculated through CFD （Computational Fluid Dynamics）. The simulation results showed that the air damping acting on catenary wires was minor, and was positive mostly, which would not cause significant deterioration to the pantograph-catenary current collection unless pantograph scraping oc- curs. Based on AR model and structural characteristics of the catenary, by inversion of Davenport lateral wind velocity spectrum and Panosfsky vertical wind velocity spectrum, the fluctuating wind field with time and space correlation for the catenary was constructed to studythe influence of the fluctuating wind speed and attack angle on the pantograph-catenary contact force through the solution to the dynamic equation. The results showedthat strong fluctuating wind field had a significant effect on pantograph-catenary current collection. The high frequency of contact force was mainly affected by fluctuating wind excitation.. During the process of the study, the contact force should remain unfiltered. The increase of wind speed may cause the increase of the amplitude of the contact force spectrum. Under certain wind speed, the wind attack angle was the important factor in af- fecting current collection. The horizontal fluctuating wind was more favorable to current collection. The ideal range of wind attack angle for maintaining a stable current collection was at 0~20°in the numerical example of Beijing-Tianjin Intercity Railway. The adjustment of pantograph-catenary dynamic equation from the theoreti- cal derivation with considering the aerodynamics can provide a reference to the further study of the catenary wind-induced vibration. The simulation results can provide a reference for the windproof design of the catenar- y.