Dynamic characterization of pantograph lifting and lowering operation process based on computational fluid dynamics and multibody system dynamics

Journal article, 2025

The pantograph protrudes above the train roof and is significantly affected by airflow. As train speed increases and reaches 450 km/h, the surrounding flow field becomes more complex, worsening the pantograph’s dynamic behavior under aerodynamic excitation. As the sole source of power acquisition for the train, pantograph stability directly impacts operational efficiency and safety. During train operation, certain pantograph lifting/lowering actions are inevitable, such as when obstacles are present on the overhead contact line, requiring the pantograph to be lifted or lowered for avoidance. This study adopted a bidirectional coupled simulation method based on Computational Fluid Dynamics (CFD) and Multibody system Dynamics (MSD, with a self-developed dynamics code) to simulate the flow-induced vibration of the pantograph. It comprehensively considered the pantograph’s active control and forced vibration characteristics to investigate its dynamic response during lifting and lowering operations. The Shear Stress Transport (SST) k-ω turbulence model and Reynolds-Averaged Navier–Stokes (RANS) equations are used to solve the flow field. The Newmark-Beta method, based on the average constant acceleration rule, was employed to solve the pantograph’s lumped mass vibration differential equations and motion constraint equations. This method had been experimentally validated. The study found that when the pantograph operated in the closed state at a speed of 450 km/h, during the lowering and lifting process, the aerodynamic lift force on the pantograph remained downward and was linearly negatively correlated with its height. This accelerated the lowering process, taking only 1.504 s, while inhibiting the lifting motion and making it difficult for the pantograph to ascend. Instead, it maintained a sustained oscillation at a fixed height of 0.911 m. In summary, during high-speed operation, the pantograph lowered rapidly but struggled to lift to its normal working height.