摘要:
分裂导线在不同风场条件下的阻力系数及干扰效应对导线风荷载的合理化设计十分重要。不同迎风角和雷诺数下分裂导线气动阻力系数特性及干扰屏蔽效应比较复杂。为了研究该干扰效应,设计长细比约为1∶30、长度约为1m 的导线节段模型试验,获得导线平均风荷载阻力系数随雷诺数、尾流干扰的变化规律;进行了不同风速和迎风方向下4、6和8分裂导线节段模型平均风荷载阻力系数试验,总结了多分裂导线阻力系数的屏蔽效应规律特性。试验结果表明,多分裂导线气动阻力系数干扰效应明显,且不同迎风方式对风荷载影响较大,风荷载明显低于现行规范规定值。分裂导线风荷载合理化设计和计算应该重视迎风角度和干扰效应的影响。
Abstract:
It is important to take into account the drag coefficient and interference shielding effect under different wind conditions in the design of bundled conductors.However,it is a com-plex problem under different wind angles and Reynolds numbers conditions.In this paper,wind tunnel test on a sectional conductor model with 1m long and 1:30 aspect ratio was firstly conduc-ted to investigate the influence of Reynolds number and wake effect on the mean drag coefficient of bundled conductors.Then,sectional model tests of 4-,6-and 8-bundled conductors under dif-ferent wind attack angles and velocities in the uniform flow were conducted to analyze the shiel-ding effect of drag coefficient of bundled conductors.The results indicate that the interference shielding effect is evident for multi-bundled conductors.In addition,the variation of the wind attack angle has great effect on the wind loads,the values of which are obviously smaller than that of the current design specification.Therefore,it is of great importance to pay attention to the influence of the wind attack angle and interference shielding on the wind load computation in the design of bundled conductors.
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