兰新高铁桥梁挡风屏对正馈线气动特性的影响

Influence of Bridge Windshield of Lanzhou-Urumqi High-speed Railway on Aerodynamic Characteristics of Catenary Positive Feeder

兰新高铁沿线受地理环境限制采用较多桥梁结构,为研究分析大风区段桥梁挡风屏对接触网正馈线气动特性的影响,基于计算流体动力学中的有限体积法及Transition SST湍流模型,建立桥梁挡风屏及正馈线计算模型;针对不同的挡风屏高度、挡风屏透风率及风速,分析接触网正馈线的气动特性差异及规律.研究结果表明:桥梁挡风屏的存在对接触网正馈线有明显的增速效应,随着挡风屏高度的增加,接触网正馈线气动升力、阻力系数均呈现先增大后减小的趋势,并在挡风屏高度4 m时达到最大值;挡风屏设置透风结构后,来流更多地通过透风结构而减小了对接触网正馈线气动特性的影响,透风率越大对正馈线气动特性的影响越小,综合考虑认为40%的挡风屏透风率在不同风速下具有很好地降低正馈线气动特性的效果.研究结果可为大风区段新建线路提供理论依据和参考.

Due to the limitation of geographical environment,many bridge structures are designed along the Lanzhou-Urumqi high-speed railway.In order to study and analyze the influence of bridge windshield on the aerodynamic characteristics of catenary positive feeder in strong wind sections,a calculation model of bridge windshield and positive feeders is established based on the finite volume method and Transition SST turbulence model in computational fluid dynamics.According to different windshield height,windshield ventilation rate and wind speed,the difference and law of aerodynamic characteristics of catenary positive feeder are analyzed.The results show that the existence of the bridge windshield has an obvious accelerating effect on the positive feeder of the catenary.With the increase of the height of the windshield,the aerodynamic lift and resistance coefficient of the positive feeder of the catenary first increase and then decrease,and reach the maximum when the height of the windshield is 4 m.After the windshield is equipped with ventilation structure,more incoming flow passes through the ventilation structure to reduce the impact on the aerodynamic characteristics of the catenary positive feeder.The greater the ventilation rate,the less the impact on the aerodynamic characteristics of the positive feeder.It is considered that 40%of the windshield ventilation rate has a good effect of reducing the aerodynamic lift resistance of the positive feeder under different wind speeds.The research results can provide theoretical basis and references for the design and construction of new lines in strong wind section.