Reasonable gap spacings between adjacent train vehicle models are of great significance for the data accuracy during a wind tunnel test. In this research, crosswind flows around 1/8th-scale high-speed train models with inter-carriage gap spacings of 0, 5, 8, 10, and 20 mm are studied using improved delayed detached eddy simulation (IDDES) with the SST (shear-stress transport) k-omega model. The numerical methodology is first validated against the wind tunnel experiment data. Then, the effects of gap spacings on aerodynamic loads and the flow field around the train are investigated. The results indicate that the side force of the tail car significantly increases with the gap spacing, in which the maximum difference occurs at 20 mm compared with the zero gap spacing, whereas the difference in the drag decreases. When the gap spacing is greater than 10 mm, the time-averaged pressure distribution, flow pattern and transient flow structures around the inter-carriage gap regions observe a significant difference from other gap spacings. Considering the overall aerodynamic effects induced by gap spacings and the practical handleability during a wind tunnel test, a gap spacing between 5 mm and 10 mm is therefore recommended for adjacent train vehicles with a 1/8th scale.

相邻列车车辆模型之间合理的间隙间距对于风洞试验中的数据准确性具有重要意义。在这项研究中，使用改进的延迟分离涡模拟 (IDDES) 和 SST 研究了 1/8 比例高速列车模型周围的侧风流，其中车厢间隙间距为 0、5、8、10 和 20 毫米。剪应力传输）k-omega 模型。首先根据风洞实验数据验证了数值方法。然后，研究了间隙间距对气动载荷和列车周围流场的影响。结果表明，尾车侧向力随间隙间距显着增大，其中与零间隙间距相比最大差异出现在20 mm处，而阻力差异减小。当间隙间距大于 10 mm 时，车厢间间隙区域周围的时均压力分布、流型和瞬态流结构与其他间隙间距存在显着差异。考虑到间隙间距引起的整体空气动力学影响和风洞试验期间的实际操作性，因此建议相邻列车车辆的间隙间距为 5 mm 至 10 mm，比例为 1/8。