多风速段下低风阻导线抗风能力实验分析及导线截面结构参数优化

低风阻导线具有能降低导线所受风载荷、减小输电线路杆塔所受风压的优点。前期研究发现改变低风阻导线截面凹槽参数会对导线抗风能力造成一定影响，但针对具体的导线截面结构优化并无深入研究。以四种不同截面形状的低风阻导线为研究对象，在风洞试验条件下探究了导线风阻系数在不同风速段中的变化规律，并利用基于最小二乘的多项式曲面拟合对风阻系数与截面结构参数之间的相关性进行回归分析。研究结果表明：在低风速10~20 m/s区间内，导线风阻系数随导线截面粗糙度增加而线性递增。在中高风速20~60 m/s区间内，导线风阻系数由截面凹槽数量与凹槽半径构成的双变量二次函数决定。通过求解函数最小值可以获得低风阻导线的优化截面结构参数。基于纳维-斯托克斯方程在COMSOL有限元软件中模拟了优化导线模型与普通低风阻导线模型在多风速段中的流场变化情况，验证了本次拟合结果的有效性。

Wind resistance test and optimal design of cross-sectional structure of a drag-reduced conductor at multiple wind speed levels

A drag-reduced conductor has advantages of reducing the wind load on the conductor and the wind pressure on the transmission line tower. Previous studies found that changing the parameters of the drag-reduced conductor cross-section groove will have a certain impact on the wind resistance of the conductor, but there is no in-depth study on the specific optimization of conductor cross-section structure. In this paper, four kinds of drag-reduced conductor with different cross-section shapes are taken as the research objects, and the variation of wind resistance coefficient in different wind speed sections is explored in a wind tunnel test. The correlation between wind resistance coefficient and cross-section structure parameters is analyzed using polynomial surface fitting based on least squares. The results show that in the low wind speed range of 10 m/s~20 m/s, the wind resistance coefficient increases linearly with the increase of conductor cross-section roughness. In the middle and high wind speed range of 20 m/s~60 m/s, the wind resistance coefficient of the conductor is determined by the bivariate quadratic function composed of the number of grooves and the radius of grooves. By solving the minimum value of the function, the optimal section structure parameters of the conductor with low wind resistance can be obtained. Based on the Navier Stokes equation, the flow field changes of the optimized wire model and the ordinary low wind resistance wire model in multiple wind speed segments are simulated in COMSOL finite element software. This verifies the effectiveness of the fitting results. This work is supported by the National Nature Science Foundation of China (No. 51707113).