Abstract This paper analyses predictions from Large Eddy Simulations of a section of a double-stacked freight train subjected to various local loading configurations under the influence of cross-wind. In particular, drag, side force and moment coefficients of double-stacked containers on a test wagon were predicted for different combinations of upstream and downstream gaps between neighbouring wagons. The mean flow field around a loaded test wagon was shown to undergo a significant topological change with increasing gap size and yaw angle. The gap range where the drag increases most rapidly was found to change as yaw angle is increased. Various topological changes to the flow over the vehicle were identified using the mean and fluctuating pressure coefficients, and a Proper Orthogonal Decomposition analysis, revealing the dominant flow mechanisms over the roof and at the leeward side of the vehicle, due to the unsteadiness in the flow over those regions. In addition to the fluctuating and extreme aerodynamic side force, the development of mean wake structure with increasing yaw angle are discussed.

中文翻译：

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侧风下货运列车内双层货车的流经和受力

摘要 本文分析了在侧风影响下受到各种局部载荷配置的双层货运列车部分的大涡模拟的预测。特别是，针对相邻货车之间的上游和下游间隙的不同组合，预测了测试货车上双层集装箱的阻力、侧向力和力矩系数。载重试验车周围的平均流场随着间隙尺寸和偏航角的增加而发生显着的拓扑变化。发现阻力增加最快的间隙范围随着偏航角的增加而变化。使用平均压力系数和波动压力系数以及适当的正交分解分析来识别车辆上流动的各种拓扑变化，由于这些区域的流动不稳定，揭示了车顶和车辆背风侧的主要流动机制。除了波动和极端的气动侧力外，还讨论了随着偏航角增加的平均尾流结构的发展。