基于刚性节段模型风洞试验的输电导线阻力系数研究

为了研究多分裂导线静力风荷载,进行了原尺寸刚性节段模型测力风洞试验,计算得到了多种直径导线阻力系数,并分析了包括雷诺数效应、屏蔽效应等因素对其结果的影响.研究结果表明,导线阻力系数试验结果较规范取值小,且由于导线表面粗糙度及紊流度的增加,会使其临界区雷诺数范围提前,尽管导线雷诺数处于名义的亚临界区域,其阻力系数依然随雷诺数变化比较敏感.对于多分裂导线而言,由于上游导线的遮挡干扰,导线整体阻力系数有所降低,必须考虑这种屏蔽效应的影响.拟合得到了考虑雷诺数效应以及屏蔽效应在内的输电导线阻力系数经验公式,为输电导线静力风荷载的计算提供一定的参考.

Study on Drag Coefficients of Conductors Based on Wind Tunnel Tests of Rigid Sectional Model

In order to investigate the static wind forces on the multi-bundled conductors, based on the wind tunnel force balance tests for rigid sectional models of single and multi-bundled conductors, drag coefficients and the influence of Reynolds number effects and shielding effects were analyzed. The results illustrate that the drag coefficients obtained by the wind tunnel tests are much smaller than those specified in the Code. And because of the surface roughness of the conductors as well as the flow turbulence, the range of Reynolds numbers in the critical region was brought forward. Moreover, although the Reynolds numbers are within the subcritical range, the drag coefficients are still very sensitive to the variance of the Reynolds numbers. For the multi-bundled conductors, the interference caused by the upstream lines reduces the integrated drag coefficients. It is stated that the influences of the shielding effects should be considered. Finally, an empirical formula involving the Reynolds number effects and shielding effects was proposed to calculate the drag coefficients of the bundled conductors, which provides references for calculating the static wind loads of conductors.