斜拉索风雨激振的数值模拟研究

为研究斜拉索风雨激振的发生机理,该文对带固定水线的斜拉索二维模型进行CFD数值模拟,得到了气动力系数随上水线位置变化的曲线,并分析了上水线对拉索气动特性的影响。将CFD计算得到的气动力系数曲线代入风雨激振二维两自由度模型中进行数值求解,实现了对风雨激振现象的完全数值模拟。然后对比风雨激振人工模拟降雨风洞试验测得的结果,分析了平均风速和脉动风速的影响。研究表明,上水线的振荡是诱发风雨激振的主要原因,且考虑风速脉动后的斜拉索振动及水线振荡更接近试验结果。

INVESTIGATION ON RAIN-WIND-INDUCED VIBRATION OF STAY CABLES BASED ON NUMERICAL SIMULATIONS

In order to investigate the mechanism of rain-wind-induced vibrations(RWIV),a series of 2-dimensional CFD models of stay cables with fixed upper rivulets were computed to obtain the curves of aerodynamic coefficients vs.the positions of upper rivulets.The influence on cable aerodynamic characteristics caused by the upper rivulet was analyzed.Correspondingly,a 2-dimensional 2DOF model of RWIV was established and a numerical program employing the curves from CFD computation achieved the complete computer-based stimulation of RWIV.By contrast with the results from an artificial rainfall wind tunnel test,the mean wind velocity and turbulence intensity were studied based on the numerical stimulation.The study shows that the oscillation of the upper rivulet is the reason causing RMIV.The simulation results also indicate that the response of the stay cable in RWIV is close to that of wind tunnel test results when the fluctuating wind is considered.