Aerodynamic uplift force improvement in single-strip high-speed pantograph via key parameter regulation with mechanism investigation

Abstract

This study addresses the significant disparity in aerodynamic uplift forces experienced by single-strip high-speed pantographs under different operating directions. A systematic numerical investigation was conducted to evaluate the influence of key geometric parameters on aerodynamic characteristics, culminating in two targeted adjustment strategies. The reliability of the computational methodology was validated through comparative analysis, which revealed less than a 6 % deviation in aerodynamic drag between the numerical simulations and wind tunnel tests. Aerodynamic decomposition revealed that the operating direction critically impacts the uplift force, which is governed by two factors: streamwise cross-strip positioning and the angular orientation of the arm hinge. These factors collectively determine the divergent aerodynamic responses of the panhead and frame during directional changes. By establishing a parametric database encompassing four strip-to-crossbar spacing configurations and six arm diameter variations, nonlinear response patterns of the uplift forces under different operating directions to geometric modifications were quantified. Both adjustment approaches, simultaneously reducing both streamwise and vertical strip-to-crossbar spacings to half of the original dimensions or increasing the upper arm spanwise diameter to 1.45 times and decreasing the lower arm spanwise diameter to 0.55 times the baseline values, successfully constrained aerodynamic uplift force deviations between operating directions within 3 %.

Keywords

• High-speed pantograph
• Aerodynamic uplift force
• Key parameter regulation
• Numerical simulation