Wake dynamics, the distribution and unsteady characteristics of pressure loads of the high-temperature superconducting maglev train

Superconducting magnetic levitation trains, designed to run at 600 km/h (Mach number 0.49), face novel aerodynamic challenges. The flow in the train-track gap, tail vortex shedding, U-shaped track, and body flow separation can cause unsteady loads, which are of potential significance for aeroelastic and fatigue considerations. This study analyzes the unsteady aerodynamic loads and wake oscillation modes of the superconducting maglev train. The improved delayed detached eddy simulation turbulence model and the shear-stress transport k–ω two-equation model are employed for numerical simulations at Mach numbers of 0.33, 0.44, and 0.49. The body pressure load distribution and fluctuation characteristics are clarified. Proper orthogonal decomposition identifies regions with high non-steady loads, while dynamic mode decomposition links these loads to flow structures and extracts key wake coherent structures. The results indicate strong pressure fluctuations at the head car nose, the first bogie, and the train underbody, with multiscale flow pulsations. Other areas have a single flow structure with a frequency of about 20 Hz. The U-shaped track induces a complex double vortex pair phenomenon in the wake, characterized by intricate motions in both spanwise and streamwise directions. These findings are valuable for the structural design of high-speed maglev trains.