Aerodynamic Features of High-Speed Maglev Trains with Different Marshaling Lengths Running on a Viaduct under Crosswinds

The safety and stability of high-speed maglev trains traveling on viaducts in crosswinds critically depend on their aerodynamic characteristics. Therefore, this paper uses an improved delayed detached eddy simulation (IDDES) method to investigate the aerodynamic features of high-speed maglev trains with different marshaling lengths under crosswinds. The effects of marshaling lengths (varying from 3-car to 8-car groups) on the train’s aerodynamic performance, surface pressure, and the flow field surrounding the train were investigated using the three-dimensional unsteady compressible Navier-Stokes (N-S) equations. The results showed that the marshaling lengths had minimal influence on the aerodynamic performance of the head and middle cars. Conversely, the marshaling lengths are negatively correlated with the time-average side force coefficient (C_S) and time-average lift force coefficient (C_l) of the tail car. Compared to the tail car of the 3-car groups, the C_S and C_l fell by 27.77% and 18.29%, respectively, for the tail car of the 8-car groups. It is essential to pay more attention to the operational safety of the head car, as it exhibits the highest time average C_S. Additionally, the mean pressure difference between the two sides of the tail car body increased with the marshaling lengths, and the side force direction on the tail car was opposite to that of the head and middle cars. Furthermore, the turbulent kinetic energy of the wake structure on the windward side quickly decreased as marshaling lengths increased.