缠绕螺旋线斜拉索气动性能的试验研究

摘要

为研究缠绕螺旋线对斜拉索气动性能的影响,进行光拉索和缠绕螺旋线拉索的测力和测压风洞试验.首先,考虑强迫振动装置的尺寸要求,制作光拉索和缠绕螺旋线拉索模型,并在拉索轴向布置7圈风压测点,其中,螺旋线直径包括2mm、3mm、4mm三种、螺旋线间距包括200mm、300mm、600mm三种；然后,在HD-2风洞实验室的强迫振动装置上进行50种工况的拉索测力和测压风洞试验；最后,在试验数据的基础上,详细研究螺旋线对拉索气动力、旋涡脱落和风压轴向相关性等的影响.研究结果表明,缠绕螺旋线能减弱斜拉索旋涡脱落的强度,使得斜拉索的风压轴向相关性显著降低；在5～20m/s的风速范围内,缠绕螺旋线拉索的平均阻力系数甚至小于光拉索的值,并随着风速的增加,风压轴向相关性降低.%In order to investigate the aerodynamic characteristics of stay cable attached with helical lines,wind tunnel tests were carried out to measure the wind forces and wind pressures on the cable.Test models of a smooth cable and cables with helical lines were made,and pressure taps were arranged on 7 cross sections of the cable models.The diameters of helical lines are respectively 2,3 and 4mm,and the distance between adjacent helical lines are 200,300 and 600mm.Wind tunnel tests with 50 cases were conducted to measure the forces and wind pressure on the cables using the forced vibration system in HD-2 wind tunnel.The effects of helical lines on the cable aerodynamic forces,vortex shedding,and the correlation coefficients along the cable axis are investigated in detail based on the experimental data.The results show that helical lines can attenuate vortex shedding and reduce the pressures correlation along the cable axis.When the test wind velocity is between 5m/s and 20m/s,the mean drag forces on the cables with helical lines are lower than the value of the smooth cable,and the correlation coefficients decrease with the increase of wind velocity.