多分裂导线屏蔽效应风洞试验评估

Wind Tunnel Test Assessment of the Shielding Effect of Bundled Conductor

与单根导线相比,多分裂导线特殊的导线布置方式使得各导线之间存在屏蔽效应。为了研究屏蔽效应的大小随风攻角、导线分裂数、导线直径的变化,在风洞中测试了不同直径的4、6、8分裂导线在不同风攻角下的整体阻力系数,并且以其较相应单根导线阻力系数的降低幅度作为参考值,评估了屏蔽效应的大小。试验结果发现:多分裂导线具有明显的屏蔽效应;屏蔽效应随着风攻角的不同产生显著变化;屏蔽效应随着导线分裂数的增多,直径的增大而趋于稳定;大直径多分裂导线的屏蔽效应可使导线的整体阻力系数降低10%以上,规范中可以考虑多分裂大直径导线稳定的屏蔽效应对于降低风荷载的有利影响。

Compared with the single conductor,the special arrangement of bundled conductors results in the shielding effect between various wires. In order to study the magnitude of shielding effect in response to different wind attack angles,division number of wires,wire diameters,we test the overall resistance coefficient of the bundled conductors（4,6,and 8）with different diameters at different wind attack angles in the wind tunnel.Taking the decrease of the resistance coefficient of corresponding single wire as reference value,we also assess the magnitude of the shielding effect. The test results show that：bundled conductors have obvious shielding effect;different wind attack angles produce a significant change in the shielding effect;the shielding effect stabilizes with the increase of the division number of wires and the diameters;the shielding effect of bundled conductors with large diameters can reduce the overall resistance coefficient by more than 10%,which illustrates the beneficial effect of the stable shielding effect of large-diameter bundled conductors in reducing the wind loads.