4分裂导线风洞试验中跨度折减法的适用性研究

跨度折减法通过系数γ缩小导线的跨度,在输电塔线系统风洞试验中应用广泛,但其对4分裂导线的适用性尚未澄清.基于4分裂导线气弹模型风洞试验,对比研究了不同跨度折减系数的两模型与正常缩尺模型的气动力和功率谱特性,并进一步探讨了湍流度和风向的影响.结果表明:导线风振响应中含有高阶振型,且气动力的平均值和脉动值随风速的增加均呈现...

Applicability of distorted span modeling in wind tunnel tests of 4-bundled conductors

The span distorted modeling is widely used in wind tunnel tests of transmission tower-line system by reducing the span of conductor through correction coefficientγ,but its applicability to 4-bundle conductors has not been clarified.Based on aeroelastic model of 4-bundled conductors,the aerodynamic force and PSD of two distorted models and one normal model are tested and com-pared,and the influence of turbulence intensity and yaw wind is further discussed.The results indicate that high order modes are involved in the response of transmission lines,and the mean and RMS values of aerodynamic force increase nonlinearly with the increase of wind speed.Turbulence has a certain effect on the increase of mean and RMS values of aerodynamic force,and could increase the discrepancy of mean force between distorted model and normal model.The aerodynamic force at both ends of the conductor is different under yaw wind,and the difference between mean values of tension is significantly higher than that of drag force.The aerodynamic characteristics of the distorted model withγ=0.8 are in good agreement with those of the normal model except that the RMS value is slightly higher than that of normal model,but a big gap of aerodynamic characteristics is observed between the distorted model withγ=0.5 and the normal model.For 4-bundled conductors,it is recommended to use a span distortion ratio around 0.8 instead of a smaller ratio.