上下臂杆直径对高速受电弓气动抬升力的影响

建立了7种不同直径上臂杆和7种不同直径下臂杆的受电弓模型，对受电弓进行空气动力学数值模拟计算，采用多体动力学方法计算了受电弓的气动抬升力，从气动力及流场特性的角度研究了受电弓上下臂杆直径对受电弓气动性能、气动抬升力的影响规律。研究结果表明:开口运行工况上臂杆气动升力和受电弓气动抬升力都随着上臂杆直径增加而增大，随着下臂杆直径增大而减小，但下臂杆直径对受电弓气动抬升力的影响较小；闭口运行工况上臂杆气动升力和受电弓气动抬升力都随着上臂杆直径增大而减小，随着下臂杆直径增加而增大；开闭口运行工况上臂杆主体杆件气动阻力仅为上臂杆气动阻力的3%~10%，气动升力为上臂杆气动升力的26%~55%，下臂杆主体杆件气动阻力为下臂杆气动阻力的10%~25%，气动升力为下臂杆气动升力的43%~68%，直径的改变对上下臂杆气动升力的影响较大，对气动阻力的影响较小；闭口运行工况上下臂杆气动阻力的绝对值都大于开口运行工况。 

Effect of upper and lower arms diameters on aerodynamic uplift force of high-speed pantograph

The pantograph models for the upper arms with seven different diameters and those for the lower arms with seven different diameters were built, and the aerodynamic numerical simulations of pantographs were carried out. The aerodynamic uplift forces of pantographs were calculated by using the multi-body dynamics method, and the effects of the upper and lower arm diameters on the aerodynamic performances and aerodynamic uplift forces of pantographs were studied from the perspective of the aerodynamic force and flow field characteristics. Research results show that both the aerodynamic lift force of the upper arm and the aerodynamic uplift force of the pantograph are larger with the rise of the upper arm diameter and are smaller with the rise of the lower arm diameter under the knuckle-downstream operating conditions, but the effect of the lower arm diameter on the aerodynamic uplift force of the pantograph is small. Moreover, both the aerodynamic lift force of the upper arm and the aerodynamic uplift of the pantograph lessens with the increase of the upper arm diameter and raises with the increase of the lower arm diameter under the knuckle-upstream operating conditions. The aerodynamic resistance of the bar of the upper arm only accounts for 3%-10% of that of the upper arm, and the aerodynamic lift force accounts for 26%-55% of that of the upper arm under both the knuckle-downstream and knuckle-upstream operating conditions. The aerodynamic resistance of the bar of the lower arm accounts for 10%-25% of that of the lower arm, and the aerodynamic lift force accounts for 43%-68% of that of the lower arm under the two conditions. The change of diameter has a great influence on the aerodynamic lift forces of the upper and lower arms and a small effect on the aerodynamic resistances. In addition, the absolute values of the aerodynamic resistances of the upper and lower arms under the knuckle-upstream operating conditions are greater than those under the knuckle-downstream operating conditions. 16 figs, 31 refs.