高速铁路接触线覆冰后气动力特性的风洞试验研究

Wind Tunnel Test on Aerodynamic Force Characteristics of Ice Coating Contact Wire for High Speed Railway

以我国高速铁路用接触线为原形,制作比例为2∶1、高为0.5m、覆冰倾斜角为45°、覆冰层厚度分别为0,3.7,7.4和14.8mm的4种接触线试验模型,进行风洞试验,测量接触线试验模型分别在5,6.5,8和10m·s-1风速下受到的顺风向阻力、横风向升力和垂直方向扭矩,分析接触线试验模型的阻力系数、升力系数随风攻角变化的规律,并运用邓哈托垂直振动理论研究接触线试验模型的气动稳定性。结果表明:无覆冰和风攻角为-45°时接触线试验模型的阻力系数和升力系数有明显的波谷,且邓哈托系数出现极小值,这表明接触线截面上的凹槽明显降低了其本身的气动稳定性;风攻角为-45°^-15°时,随着接触线试验模型覆冰厚度的增加,邓哈托系数减小,这表明覆冰厚度的增加会降低接触线的气动稳定性。

Taking the contact wire for high speed railway in China as the prototype,four different ice coating contact wire 2∶1 scale models of 0.5 m high,ice coating inclination angle 45°,with the ice coating thickness of 0,3.7,7.4 and 14.8 mm were made and tested in wind tunnel.The along-wind drag forces,across-wind lift forces and vertical torsion moments of the models were measured under the wind speed 5,6.5,8 and 10 m · s-1 respectively.The variations of the drag and lift coefficients with different wind attack angles of the models were analyzed and Den Hartog vertical vibration theory was used to analyze the aerodynamic stability.The results show that the drag and lift coefficients of the ice-free contact wire model at-45° wind attack angle have obvious wave troughs,and the Den Hartog coefficient has a minimum,which shows that the groove on the cross section of contact wire has obviously reduced its aerodynamic stability.Under the wind attack angles from-45° to-15°,Den Hartog coefficient decreases with the increase of ice coating thickness,which indicates that the increase of ice coating thickness will reduce the aerodynamic stability of contact wire.