垂度对覆冰导线静力三分力的影响研究

Numerical simulation on aerodynamic coefficients of iced conductors with sag

针对当前关于覆冰导线的风洞试验研究和数值模拟研究中普遍采用等截面形式的节段模型作为研究对象,通过CFD方法对有垂度的典型覆冰导线进行数值模拟分析。论述典型覆冰导线数值模拟的网格划分技巧,分析由于逆压梯度引起分离的流动模拟的湍流模型选取原则,给出湍流模型与壁面无量纲距离之间的关系;讨论网格无关性及时间无关性的测试过程以及两者对于计算结果精度的影响,分析具有垂度的覆冰导线在不同工况下的三维流动特性。研究结果表明:垂度的影响会导致漩涡分离点靠后,使得覆冰导线前后压差变大,导致阻力系数相应增加,而当前关于覆冰导线的研究中普遍采用不考虑垂度的节段模型作为研究对象,忽略了覆冰导线沿长度方向漩涡脱落的三维特性,低估了垂度对三分力的影响。因此,高压输电线的分析必须考虑垂度对于气动力的影响,本文为类似构件的数值模拟分析提供具有参考价值的方法和建议。

Abstract： According to the uniform section model of iced conductors which are commonly used in the windtunnel tests and numerical simulation research, the CFD method was used to simulate the typical iced conductorwith sag. The meshing technique of numerical simulation for typical iced conductors was discussed. The selectionprinciple of turbulence model used in the separation flow simulation induced by inverse pressure gradient wasanalyzed, and the relationship between the turbulence model and the dimensionless distance was given. The testprocess of mesh independence and time independence and the influences of both on the accuracy of thecalculation results were discussed in detail. Finally, the three-dimensional flow characteristics of the icedconductors with sag under different conditions were analyzed. The research results show that the influence of sagwill cause the vortex separation to move backward, so that the pressure difference between the front and back ofthe iced conductor becomes larger, resulting in a corresponding increase in the drag coefficient. The researches oniced conductors, which take the uniform section model without sag as the research object, obviously ignore thethree dimensional characteristics of the vortex shedding along the length direction of the iced conductor.Therefore, the influence of sag of the conductor on aerodynamic force must be considered in the analysis of highvoltage transmission lines. This paper provides some reference methods and suggestions for the numericalsimulation of similar components.