A high-speed train will likely experience hazardous driving environments because of the transient effect of complex airflow condition when the train runs on the infrastructure scenario consisting of the tunnel–bridge–tunnel under crosswind. The evolution of aerodynamic loads and flow structure is investigated by numerical simulations. In these simulations, the arrangement of an infrastructural scenario refers to a real prototype under construction. Results indicate the flow structure and pressure distribution around a train change from a symmetrical state in the tunnel to a remarkable asymmetry state in the bridge within 0.1 s. This phenomenon causes a sharp aerodynamic shock on the train body. The coupling effect of the crosswind environment and the transformation of the train running scenario will likely affect the transient aerodynamic response. The maximum values of different aerodynamic loads exhibit time-resolved discrepancy when a train runs in ISTBT. The transient characteristics of the aerodynamic loads strengthen with the increase in wind speed but weaken with the increase in train speed. Such characteristics will likely deteriorate further if the wind direction is in the opposite direction relative to that of a moving train.

当高速列车在侧风作用下的隧道-桥梁-隧道组成的基础设施场景下运行时，由于复杂的气流条件的短暂影响，高速列车可能会遇到危险的驾驶环境。通过数值模拟研究了空气动力载荷和流动结构的演变。在这些模拟中，基础设施方案的布置是指正在建造的真实原型。结果表明，列车周围的流动结构和压力分布在0.1 s内从隧道中的对称状态变为桥梁中的显着非对称状态。这种现象会在火车车身上产生剧烈的空气动力学冲击。侧风环境与列车运行状况的转换的耦合效应可能会影响瞬态空气动力响应。当火车在ISTBT中行驶时，不同空气动力学负载的最大值表现出时间分辨的差异。气动载荷的瞬态特性随着风速的增加而增强，但随着列车速度的增加而减弱。如果风向与行驶中的火车的方向相反，则此类特性可能会进一步恶化。