Abstract This paper studies the crosswind aerodynamics of an interior train and flat box bridge-deck system via a series of wind tunnel experiments in wind angle of attack α = [−12°, 12°]. Aerodynamics of the train- and bridge-only models is measured as benchmarks under similar conditions. Upon comparing with the train- and bridge-only cases, the lateral aerodynamic interference between the train and bridge-deck is qualitatively identified by smoke-wire visualization and quantitatively detected by surface pressure and flow profiles located 8 mm upstream from the train model and 490 mm downstream from the bridge-deck model. Generally, the lateral aerodynamic interference on the train model is primarily manifested by suppression of underbody vortex shedding, shielding effect of bridge-deck leading-edge, and quasi-Reynolds number effect. Compared to the train-only case, the suppression of underbody vortex shedding reduces fluctuating drag, lift, and moment coefficients, whereas the shielding effect decreases the mean drag coefficient. The quasi-Reynolds number effect, owing to the accelerated and turbulent approaching flow over the rounded shoulder of the train model as α varies, abruptly alters drag, lift, and moment coefficients mimicking the classical Reynolds number effect, while the inflow Reynolds number remains unchanged. On the other hand, the lateral aerodynamic interference on the bridge-deck model is chiefly presented as flow transition promoting effect and intensifying effect on bridge-deck trailing-edge flow separating. Compared to the bridge-only case, the flow transition promoting effect leads to the global centerline of the bridge-deck aerodynamics to be parallel shifted about 4° to the positive direction of α, while the intensifying effect increases fluctuating drag, lift, and moment coefficients. Finally, the aerodynamics of the whole train-bridge system is briefly discussed.

中文翻译：

---

内部列车与扁平箱式桥面之间的横向气动干扰

摘要 本文通过风攻角α = [−12°, 12°]的一系列风洞实验，研究了内部列车和平箱桥-甲板系统的侧风空气动力学特性。列车模型和桥梁模型的空气动力学在类似条件下作为基准进行测量。与仅列车和桥梁的情况相比，列车与桥面之间的横向气动干扰通过烟线可视化定性识别，并通过位于列车模型上游 8 毫米和 490 毫米的表面压力和流动剖面进行定量检测。 mm 桥面模型下游。一般来说，列车模型的侧向气动干扰主要表现为车身底部涡脱落抑制、桥面前缘屏蔽效应和准雷诺数效应。与仅列车的情况相比，底部涡旋脱落的抑制减少了波动的阻力、升力和力矩系数，而屏蔽效应降低了平均阻力系数。准雷诺数效应，由于随着 α 变化，加速和湍流接近流过列车模型的圆肩，突然改变阻力、升力和力矩系数，模仿经典雷诺数效应，而流入雷诺数保持不变. 另一方面，对桥面模型的横向气动干扰主要表现为流动过渡促进作用和对桥面后缘流分离的强化作用。与仅桥接的情况相比，流动过渡促进效应导致桥面空气动力学的全局中心线向α的正方向平行移动约4°，而强化效应增加了波动的阻力、升力和力矩系数。最后，简要讨论了整个列车-桥梁系统的空气动力学。