Aerodynamic Characteristics Analysis of High-Speed Train Pantograph under Various Crosswind and Train Velocity Conditions

As the velocity of trains continued to increase, the aerodynamic challenges posed by the complex and variable characteristics of higher-speed pantographs under different operating conditions and crosswind velocities became more pronounced. These challenges significantly compromised the stability of the pantograph, jeopardizing the safety of train operations. This study aimed to investigate the impact of various operating conditions of higher-speed pantographs, train velocities, and crosswind conditions on the non-constant aerodynamic characteristics of pantographs. Numerical simulations were conducted using the improved delayed detached-eddy simulation (IDDES) method, and the results were validated against wind tunnel test data. The results indicated that the flow field and vortex patterns in the rear region of the pantograph were significantly more intricate than those in the knuckle-upstream region. As the velocity increased, the aerodynamic lift coefficient of the upper part of the pantograph increased whereas its drag coefficient decreased; whereas for the lower part, both the aerodynamic lift and drag coefficients decreased. The overall vortex-shedding strength of the pantograph flow field increased, and the most significant changes in vortex behavior occurred in the lower part of the pantograph, particularly at the bottom. The lift of the pantograph components exhibited significant fluctuations as the crosswind velocity increased, with noticeable abrupt changes and transitions occurring at a crosswind velocity of 10 m/s. In contrast to the effects of the increase in velocity, the overall vortex structure of the pantograph exhibited superposition shifting toward the diagonal rear as the crosswind velocity increased, resulting in a more complex vortex pattern.