Abstract In the crosswind environment, the flow field around a bridge pylon is complex and variable so that the vehicles are prone to side slip when passing by this region. In this situation, safety and comfort are severely affected. In this study, a dynamic coupling method that uses computational fluid dynamics (CFD) coupled with multibody dynamics was adopted to investigate the aerodynamic performance and dynamic response of a sedan passing by a bridge pylon in a crosswind. The overlapping grid technique was used to achieve the movement of the sedan in the CFD simulation. The mechanism of the interaction between the flow field around the sedan and the wake vortex around the bridge pylon was demonstrated. The influence of crosswind type on the aerodynamic performance and dynamic response was further studied. The results show that the flow field around the sedan could greatly influence the behavior of the sedan, mainly in terms of changes in lateral displacement and yaw angle. Additionally, the dynamic coupling method provides a more direct and realistic way to understand the interaction between the aerodynamic loads and the dynamic responses. Of the different wind types considered (sinusoidal, linear, step), the step crosswind produces the biggest average lateral force and yaw moment resulting in the largest lateral displacement and yaw angle.

中文翻译：

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侧风下通过桥塔的轿车气动性能动态耦合分析

摘要 在侧风环境下，桥塔周围流场复杂多变，车辆通过该区域时容易发生侧滑。在这种情况下，安全性和舒适性受到严重影响。在本研究中，采用计算流体动力学（CFD）与多体动力学耦合的动态耦合方法，研究了轿车在侧风中通过桥塔的空气动力学性能和动态响应。在CFD模拟中使用重叠网格技术来实现轿车的运动。论证了轿车周围流场与桥塔周围尾流涡相互作用的机理。进一步研究了侧风类型对气动性能和动态响应的影响。结果表明，轿车周围的流场可以极大地影响轿车的行为，主要是横向位移和偏航角的变化。此外，动态耦合方法提供了一种更直接和现实的方式来理解空气动力载荷和动态响应之间的相互作用。在考虑的不同风类型（正弦、线性、阶梯）中，阶梯侧风产生最大的平均横向力和偏航力矩，从而导致最大的横向位移和偏航角。