缠绕螺旋线斜拉索气动性能的数值模拟

Numerical study on the aerodynamic characteristics of stay cables with helical lines

为研究螺旋线对斜拉索气动性能的影响,采用Fluent软件的LES模块对光拉索和缠绕螺旋线拉索进行数值模拟。首先,建立了光拉索和缠绕螺旋线拉索的数值计算模型,并在拉索轴向布置9个截面的风压和风速监测点;然后,采用Fluent软件的大涡模拟模块进行了数值计算;最后,在数值模拟数据的基础上,研究了螺旋线对拉索平均阻力系数、脉动升力系数、旋涡脱落频率、风压和风速的轴向相关性、绕流流场等的影响。研究结果表明:在风雨激振发生的雷诺数范围内,缠绕螺旋线能减小拉索的平均阻力系数;破坏规则的旋涡脱落,减小脉动升力系数,降低气动力在拉索轴向方向的相关性。

In order to study the aerodynamic characteristics of stay cable attached with helical lines, LES Module of Fluent Software was used to conduct numerical simulations. First, two kinds of computational models were established, including smooth and helical cables. Detection points were arranged on 9 cross sections to detect wind pressures and wind velocities. The diameters of helical lines included 2, 3 and 4 mm, and the distance between adjacent helical lines included 200, 300 and 600 ram. Second, numerical simulations using aforementioned parameters were carried out to obtain aerodynamic characteristics of stay cable. Finally, the effects of the helical lines on the mean drag coefficient, fluctuating lift coefficient, vortex shedding, and the correlation coefficient along the cable axis were investigated in detail base on the data obtained from numerical simulations. The results show that the mean drag and fluctuating lift coefficients of the helical cable are both less than the values of smooth cable. Helical lines can break the regular vortex shedding, and decrease the correlation coefficients of wind pressures and wind velocities along the cable axis.