光圆与非光圆绞突覆冰输电导线气动力特性分析

Aerodynamic Characteristics Analysis of Smooth Circular and Non Smooth Circular Ice-coated Conductors

现有针对覆冰输电导线风致振动的模拟研究大多是将导线简化为理想光圆截面考虑其气动力特性的,对于实际导线绞突的截面特点考虑不足。采用Fluent软件研究覆冰光圆与非光圆绞突截面导线的气动力特性,分析二者气动力系数在不同风速、覆冰厚度、覆冰形状和导线直径时的特点和差异。结果表明:两种截面覆冰导线气动力系数差异较大,其中,阻力系数和扭转系数最大相对偏差可达100%,升力系数最大相对偏差可达-175%。采用非光圆绞突截面导线会增加周期内涡脱落的数量,使其波动更加剧烈。覆冰为新月形时,采用光圆截面导线会低估导线顺风向位移,高估横风向位移;覆冰为D形时,采用光圆截面导线比非光圆绞突截面导线下波动较为平缓且更有规律,会高估顺风向位移,低估横风向位移。鉴于两种截面覆冰导线在气动力、涡脱图和位移响应均存在较大差异,覆冰输电线系统精细化抗风设计时应考虑导线截面绞突特性对其气动力的影响。

Most of the existing simulation studies on the wind-induced vibration of ice-coated conductors simplify the conductor to an ideal smooth circular section and accept its aerodynamic characteristics,but the section characteristics of the actual conductor twist are not considered enough.In this study,Fluent software is used to study the aerodynamic characteristics of ice-coated smooth circular and non smooth circular twisted section conductors,and to analyze the characteristics and differences of their aerodynamic coefficients at different wind speeds,icing thickness,icing shape and conductor diameter.The results showed that the aerodynamic coefficients of ice-coated conductors with two sections were quite different,among which the maximum relative deviation of drag coefficient and torsion coefficient could reach 100%,and the maximum relative deviation of lift coefficient could reach-175%.The use of non smooth circular twisted section conductor could increase the number of vortex shedding in the cycle and made its fluctuation more violent.When the icing was crescent shaped,the smooth circular section conductor could underestimate the downwind displacement and overestimate the crosswind displacement of the conductor.When the icing was D-shaped,the fluctuation of smooth circular section conductor was smoother and more regular than that of non smooth circular twisted section,which could overestimate the downwind displacement and underestimate the crosswind displacement.In view of the large differences in aerodynamic force,vortex shedding diagram and displacement response between the two types of coated ice conductors,the influence of conductor cross-section stranded characteristics on aerodynamic force should be considered in the fine wind resistance design of coated ice transmission line system.