Chinese-hat突变风下高速列车在桥上交会的安全性分析

Safety Analysis of High-speed Train Passing on the Bridge under the Chinese-hat Sudden Wind

与平地线路相比,大风对高架桥上运行列车的安全影响更加突出。文章以CRH3某型高速列车为原型建立了空气动力学模型,基于Chinese-hat突变风模型,采用局部动态层变法对桥上列车交会过程进行了仿真分析,研究了突变风对桥上交会列车的气动力系数及安全性影响。结果表明:与横风相比,突变风致高速列车表面压力明显加大。以背风侧列车为例,中间车的压力随突变风风速变化,且其极值是横风的15~30倍。对比两风场下的气动力系数,发现迎风侧列车和背风侧列车分别在头车接近中间车、尾车离开中间车时运行稳定性较差;将突变风下交会两车的气动力及气动力矩输入到动力学模型中,发现在1.50 s和1.72 s时突变风下迎风侧列车的安全性最低,需要在交会过程中加以重视。

Compared with the flat ground line,the impact of strong wind on the safety of running train on the viaducts is more prominent.In this paper,the aerodynamic model is established for a certain type of CRH3 high-speed train.Based on the Chinese-hat sudden wind model,the local dynamic layer transformation method is used to simulate and analysis the process of train passing on the bridge,and the influence of sudden wind on aerodynamic coefficient and safety of trains passing on bridge is studied.The results show that,compared with crosswind,the surface pressure of high-speed train caused by sudden wind is obviously larger.Taking the train on the leeward side as an example,the pressure value of the intermediate train changes with the sudden wind speed,and its extreme value is 15~30 times that of the crosswind.By comparing the aerodynamic coefficients under the two wind fields,it is found that the running stability of the windward side train and the leeward side train is poor when the head train approaches the middle car and the tail train leaves the middle car respectively.By inputting the aerodynamic force and aerodynamic moment of the two vehicles passing under the sudden wind into the dynamic model,it is found that the safety of the train on the windward side under the sudden wind is the worst at 1.50 s and 1.72 s,which needs to be paid attention to in the process of train passing.