450 km/h列车与路堤之间的相互作用可能会导致气动特性的非线性变化，引起列车在垂直方向上的不稳定。以450 km/h高速列车在路堤上的运行情况为研究对象，建立了列车和路堤三维气动仿真结构模型，探讨了列车在不同运行工况下的表面压力分布和列车风与不同风向的侧风耦合对列车外流场结构的影响，采用Q准则分析了合成风所导致的涡量差异。研究结果表明，在车速为450 km/h同一条件下，在风向角为0° ~ 90°时，头车压力最值与流场速度随风向角增大而增大，而在风向角为90° ~ 180°时，变化则相反；与列车顺风行驶相比，逆风行驶时，列车表面的涡流区区域明显更大，且车身脱落的涡结构向车尾聚集；随着车速提升，列车表面的涡量值显著增大，车速450 km/h时涡量比250 km/h时增大51.3%；列车在路堤上行驶时侧风风向角对其气动升力和阻力影响很大，列车所受阻力与升力随着风向角增大而呈现先增大后减小趋势，横风下（即风向角90°）列车的气动性能最差，在0° ~ 90°与90° ~ 180°时，列车气动力变化趋势大体呈“对称”分布。

The interaction between a 450 km/h train and an embankment may lead to nonlinear changes in aerodynamic characteristics, causing instability of the train in the vertical direction. The operation of a 450 km/h high-speed train on an embankment was taken as the research object, and a three-dimensional aerodynamic simulation model of the train and the embankment was established to explore the surface pressure distribution of the train under different operating conditions and the influence of the coupling of the train wind and the sidetrack winds with different wind directions on the structure of the train's external flow field, and the vorticity difference caused by the synthesized winds was analyzed by adopting the Q-criterion. The results indicate that the headway pressure maximum and flow field velocity increase with the increase of direction angle in the range of from 0° to 90° under the same condition of speed of 450 km/h, while the change is opposite in the range of from 90° to 180°. Compared with the train running downwind, when the train is running upwind, the vortex area is obviously larger, and the vortex structure falling off the body gathers towards the rear of the train. As the speed increases, the vorticity on the train surface increases significantly. The vorticity at 450 km/h is 51.3% higher than that at 250 km/h. The cross-wind direction angle has a great influence on its aerodynamic lift and resistance when the train running on an embankment, and the drag and lift of the train increase first and then decrease with the increase of the wind direction angle. The aerodynamic performance of the train under the cross wind (that is, the wind direction angle of 90°) is the worst, and the aerodynamic change trend of the train is generally "symmetrical" when it changes within the ranges of from 0° to 90° and from 90° to 180°.