平原上不同长度集装箱列车横风载荷的数值研究

Numerical Study on Crosswind Loads of Container Trains in Different Length on Plain

对在横风角为90°的10级横风作用下平原上以120 km/h速度运行的集装箱列车的空气动力载荷进行数值研究。采用平原大气边界底层速度型模拟运行环境,研究对象包括5种模型:机车分别牵引2辆、3辆、10辆载有集装箱的平车的列车模型以及1辆、3辆集装箱平车的周期边界模型。结果表明,机车尾流会削弱第1辆车所载集装箱的升力,第2辆车所载集装箱受到的升力最大;前车尾流导致后车的来流风向角和侧向力依次减少,第1辆车集装箱所受侧向力最大;第2辆车集装箱所受翻滚力矩最大,前3辆车集装箱所受翻滚力矩值比较接近;随列车长度增加,气动载荷在达到其最大值后呈逐渐下降趋势,尾车的绕流作用导致尾车集装箱的气动载荷迅速减少。用周期边界模型模拟长集装箱列车中段的空气动力载荷,其集装箱所受翻滚力矩约为整列车中最大值的80%～84%。

Aerodynamic loads of long formulation container trains running at a speed of 120 km/h on a plain under a crosswind of the 10 Beaufort scale with a 90° wind angle were studied numerically.The velocity profiles of the atmospheric boundary layer over a plain were used to simulate the working conditions of the trains to be studied.The train models of one locomotive hauling 2,3,and 10 container cars respectively,and the periodic boundary models of trains formed of 1 and 3 container flat cars respectively were researched.The results indicate as follows： The lift of the container on the 1st car is weakened by the wake of the locomotive and the container on the 2nd car is subjected to the biggest lift;the yaw angles and side forces of the rear container cars are reduced in sequence by the wake of the front cars,and the side force acting on the container on the 1st car is the biggest;the roll moment of the container on the 2nd car is the biggest,and the roll moments of the containers on the front 3 cars are basically at the same level;upon reaching the utmost,the aerodynamic loads will decrease gradually with increasing of car number,and the aerodynamic load of the container on the last car will drop rapidly due to the wake around the last car.The periodic boundary models are used to simulate the aerodynamic loads of the middle segment of the long container train,the roll moments of which are 80%～84% of the utmost aerodynamic load of the whole train.