The present study examines the possibilities of transferring drag measurement results on reduced-scale train models to the respective full-scale vehicle. A comprehensive experimental and numerical study of the boundary layer and skin friction along trains is performed, focusing on Reynolds number effects. The data are supplemented by an extensive literature study and compared with different approaches from flat plate theory. Good agreement can be found when using the appropriate empiric coefficients and boundary conditions. Simultaneously, the difficulties in determining the skin friction drag of trains due to three-dimensional effects and surface roughness become apparent. The ground simulation analysis, including the effects of ground roughness due to ballast and sleepers, reveals a significant effect of the ground conditions on the vehicle’s aerodynamic drag. Additionally, the effects of elements mounted on the train roof are investigated for different upstream flow conditions. Finally, a scaling method is proposed to transfer drag results from model-scale to full-scale trains based on the findings.

本研究研究了将减缩火车模型上的阻力测量结果转移到相应的全尺寸车辆的可能性。进行了沿火车的边界层和皮肤摩擦的综合实验和数值研究，重点是雷诺兹数字效果。大量的文献研究对这些数据进行了补充，并与平板理论中的不同方法进行了比较。当使用适当的经验系数和边界条件时，可以找到很好的一致性。同时，由于三维效应和表面粗糙度，确定列车的皮肤摩擦阻力的困难变得明显。地面模拟分析，包括压载物和枕木对地面粗糙度的影响，揭示了地面条件对车辆空气动力阻力的显着影响。另外，针对不同的上游流动条件，研究了安装在列车车顶上的元件的影响。最后，提出了一种基于结果的缩放方法，将阻力结果从模型比例传递到全比例列车。