不同类型横风下高速列车气动性能研究

Research on Aerodynamic Performance of High-speed Train Subjected to Different Types of Crosswind

为研究不同类型风载荷下列车空气动力学性能,数值模拟了列车在均匀风和指数风两种不同类型横风作用下的气动特性。建立列车空气动力学模型,通过网格独立性检验选取合适的仿真计算网格。研究均匀风和指数风对列车迎风侧来流速度、列车气动力、车体表面压力和列车周围流场特性的影响。相比指数风载荷,均匀风条件下列车迎风侧来流速度较大,列车受到的侧力和倾覆力矩要大18%左右。通过对比列车在平地、复线路堤两种轨道基础形式上运行时空气动力学性能差异,发现列车在复线路堤背风侧运行时气动性能较差。研究结果表明:均匀风和指数风载荷作用下的列车气动性能差异较大;在横风作用下头车受到的侧力与倾覆力矩最大,且安全性最差;列车在路堤背风侧轨道运行时受到的气动载荷大于平地运行时的列车气动载荷。

In order to research the aerodynamic performances of a train subjected to different types of wind, the aerodynamic performances of the train under the uniform wind and exponential wind are numerically simulated, respectively. The train aerodynamic model is established for the numerical simulation, and grid independence is made for selecting the appropriate computing grid. The effect of different types of crosswind on the incoming flow of the windward of the train, the aerodynamic forces of the train, pressure distribution on the train and flow field around the train are investigated. Comparing to the exponential wind, the incoming flow velocity of the windward of the train subjected to the uniform wind is larger, and the side force and overturning moment of the train are about 18% larger than those of the train subjected to the uniform wind. By comparing the differences in the aerodynamic performances of the train running on the flat ground and embankment, it is found that the aerodynamic performance of the train is worse when the train is running on the leeward side of the embankment. Results show that there are considerable differences in aerodynamic performances of the train subjected to the uniform wind and exponential wind. The lateral force and overturning moment of the head car are largest and the running safety is the worst among all cars. The aerodynamic forces of the train running on the leeward side of the embankment are larger than those of the train running on the flat ground.