兰新铁路隧道与路堤相连处防风过渡段接触网风场特性研究

Study on Wind Field Characteristics of Catenary along Wind-break Transition Section at Tunnel and Embankment Connection of Lanzhou-Urumqi Railway

接触网处风场特性对于接触网结构安全及弓网受流具有重要影响,为研究防风设施对接触网处风场特性的影响,根据兰新铁路隧道与路堤相连防风过渡段的实际结构,采用模型实验与数值计算相结合的方法,对列车在隧道内运行、出隧道在无挡风墙及含双侧3m高通透型挡风墙路堤上运行时接触网处的流场特性进行研究,得到上述过渡段接触网不同位置的速度特性。结果表明:在隧道口与5m高路基双侧设3m高通透型挡风墙时,可改善过渡段接触网处风场特性,使接触网附近风速变化平缓;但由于受路堤护坡及挡风墙绕流作用,隧道口处垂直列车方向的速度峰值增大;列车从隧道驶出并进入防风段的整个过程中,接触网处风速变化剧烈,在实际运行中应予以重视。

The work performance of the catenary system in electric railway depends on wind field characteristics around this system.Therefore,to ensure the safety and contact quality of a pantograph-catenary system,the wind-break is proposed.According to the actual structure of the wind-break transition section connecting the tunnel and embankment of Lanzhou-Urumqi railway,a model test was combined with numerical simulation to study the flow field characteristics at the overhead contact system when the train ran inside the tunnel,outside the tunnel without wind-break wall and on the embankment with 3 m high ventilated wind-break wall on both sides of the embankment.The velocity variation characteristics of the overhead contact system at different positions of the transition section were obtained.Results show that the wind-break wall can effectively improve wind field characteristics surrounding the catenary system when a train passes the transition region between the tunnel and the embankment.However,the flow formed at the limited space between wind-break and embankment leads to the increase of velocity peak at the tunnel portal. Moreover,the wind velocity close to the catenary system changes drastically in the entire process when the train leaves the tunnel and enters the wind-break section.Therefore,attention should be paid to the drastic wind velocity variation in practical operation.