基于姿态变化的列车侧风安全性研究

Study on Safety of Train in Side Wind with Changing Attitudes

从流固耦合振动出发研究列车侧风安全性问题。对25 m/s横风环境下以250 km/h的速度运行在高为10 m的高架桥上的列车,首先锁定其悬挂系统,不考虑其姿态变化,进行列车外流场计算。然后以此流场作为初始场,释放悬挂系统,考虑列车与空气介质的相互作用,采用动态网格技术,对列车系统动力学和列车空气动力学进行联合同步仿真。列车在横风作用下自适应得到一个动平衡状态,总体上看,新姿态下作用在车体质心的等效集中气动力较悬挂系统锁定时有所增加。为了比较流固关系考虑与否对列车影响的差异,将悬挂系统锁定情况下的气动力加载到列车上进行动力学分析。计算结果表明,考虑流固关系的列车在侧风下安全性更差。

Safety of trains under the side wind was studied from the point of fluid-solid vibration.For the train running on the 10 m high viaduct at the speed of 250 km/h in the 25 m/s side wind,the outer flow field was computed with suspensions locked.Considering the interaction between the train and the air,simulations of the train system dynamics and aerodynamics were done synchronously with the dynamic mesh technology under the conditions of the flow field being taken as the initial field and suspensions unlocked.The train adapted itself to a dynamic balance under the action of the side wind.The equivalent concentrated air forces acting on the centre-of-mass of the car body in the new attitude are bigger than those when suspensions are locked.In order to find the difference of the responses of the trains with and without fluid-solid interaction,the air forces with suspensions locked were applied on the train and the system dynamic simulation was done.The results show that safety of trains under the side wind gets worse when fluid-solid interaction is taken into account.