针对国内动力集中型动车组以160 km/h的速度在明线运行时整车平稳性良好，但在通过单线隧道时尾车出现周期性横向晃动的问题，采用重叠网格技术和Fluent UDF自定义函数建立列车运行时流场和车辆动力学耦合的求解方法，并通过现车试验验证该数值计算方法，进而分析阻塞比对尾涡结构、气动力和尾车横向晃动的影响。研究结果表明： 1）当阻塞比大于0.350时，列车尾部涡流结构被限制在较窄的水平空间内，削弱了涡流交替脱落的特征，尾车车头两侧流场基本对称，尾车所受横向力较小。2）当隧道净空面积为35.20 m²（阻塞比为0.309）和42.06 m²（阻塞比为0.259）时，尾车横向力正、负峰值分别为2 332、-2 483 N与2 430、-2 499  N。3）阻塞比的减小会加剧尾车的横向晃动，但当隧道截面扩大至一定程度后，尾车横向晃动强度的增长速度变得平缓。4）当列车通过净空面积为35.20、42.06 m² 2种隧道时，尾车所受交变的横向力主频分别为2.05、2.20 Hz； 随着隧道阻塞比的减小，横向力和横向加速度的主频均增大。

Multiple-car trains stably run at 160 km/h on open tracks, but the tail car periodically shakes in the lateral direction when traversing through single-track tunnels. In this study, a coupled solution method for the flow field and vehicle dynamics during train operation is proposed by integrating overset grid technology and fluent user-defined functions. The validity of this calculation method is verified through on-site vehicle tests. Subsequently, the effects of the tunnel blockage ratio on the trailing vortex structure, aerodynamic forces, and lateral shaking of the tail car are systematically analyzed. The results reveal the following: (1) When the blockage ratio exceeds 0.350, the trailing vortex structure of the train is confined to a narrow horizontal space, weakening alternating vortex shedding. At the same time, the flow field on both sides of the nose section of the tail car is approximately symmetrical, resulting in a small lateral force acting on the carriage. For tunnels with cross-sectional areas of 35.20 m² (blockage ratio is 0.309) and 42.06 m² (blockage ratio is 0.259), the lateral force amplitudes of the tail car are 2 332 N (－2 483 N) and 2 430 N (－2 499 N), respectively. (2) A decrease in the blockage ratio exacerbates the lateral shaking of the tail car. However, the growth rate of shaking intensity decreases once the tunnel cross-section is expanded to a certain extent. When the train passes through the 35.20 and 42.06 m² tunnels, the dominant frequencies of the alternating lateral force on the tail train are 2.05 and 2.20 Hz, respectively. As the blockage ratio decreases, the dominant frequencies of both the lateral force and lateral acceleration increase.