Abstract The complex mechanical configuration and non-streamlined design of the bogie adversely affect the aerodynamic performance of high-speed trains. Optimizing the underbody flow structure is a key strategy to reduce aerodynamic drag. This study introduces two types of bogie bottom fairings designed for the head car and establishes four computational models with varying covering structures. Aerodynamic performance is analyzed using the improved delayed detached eddy simulation (IDDES) method, based on the shear – stress transport (SST) k–ω turbulence model. The numerical simulations are validated through wind tunnel testing of a full-scale bogie, with an error margin below 13.46%. Results demonstrate that the proposed covering schemes substantially reduce aerodynamic drag. Specifically, integrating flat bottom and side fairings reduces the drag coefficient of the head car by 22.7% and that of the entire train by 10.6%. These findings provide valuable guidance for the implementation of bogie covering structures and offer significant insights into the aerodynamic design optimization of high-speed trains.
Xie et al. (Sat,) studied this question.