Aerodynamic performance of high-speed maglev trains traversing arc-shaped porous barriers under crosswind

Under strong crosswind conditions, as a 600 km/h high-speed maglev train traverses an arc-shaped porous barrier, the train experiences abrupt and drastic changes in aerodynamic loads. To investigate this phenomenon, a three-dimensional transient computational fluid dynamics (CFD) model was developed, in which an overset grid technique combined with the improved delayed detached eddy simulation (IDDES) method was employed to simulate the coupled crosswind–train–bridge–barrier system. How barrier aperture and train speed influence aerodynamic force coefficients and flow field evolution is examined in this study. It is demonstrated that significantly greater abrupt changes amplitudes and peak change rates in aerodynamic coefficients during train entry and exit are caused by a solid barrier compared to a porous barrier, with the most intense dynamic response being shown by the tail car. Behind the solid barrier, lower mean values but higher fluctuations are exhibited by aerodynamic loads. The dynamic impact is intensified by increasing train speed, following a power-law growth, while both the mean and statistical dispersion of aerodynamic coefficients are elevated by enlarging the barrier aperture. A fundamental difference in wake flow is identified: Initial vortices are weakened and flow reorganization is promoted by the porous barrier, whereas larger-scale vortex shedding is induced by the solid barrier. Consequently, a greater pressure differential across the car body is produced under the solid barrier condition. An empirical basis for designing targeted measures to enhance the operational aerodynamic stability of high-speed maglev trains is provided by these findings.