中文摘要：

风致舞动是一种大幅值驰振现象,在输电导线覆冰时经常发生,是输电导线最为严重的灾害之一。为了揭示输电导线风致舞动的致灾机理,本文采用基于双向耦合的CFD数值模拟方法对新月形覆冰导线舞动过程进行模拟分析,研究了不同风速下覆冰导线气动负阻尼的变化规律。研究结果发现,覆冰导线在横向不会产生气动负阻尼,而在竖向和扭转方向的部分风攻角下会产生气动负阻尼。当结构气动负阻尼大于结构固有阻尼时,覆冰导线形成发散的自激振动。进一步研究表明,当覆冰导线同时发生竖向和扭转方向气动发散时,扭转振动发散会改变覆冰导线的风攻角,从而改变竖向和扭转方向的气动阻尼。随着扭转方向的气动负阻尼和固有阻尼相抵消,覆冰导线的扭转振动渐渐趋于稳定。

英文摘要：

A wind-induced galloping is a large-amplitude vibration phenomenon,often occurs on the iced conductor and is one of most serious disasters of the transmission line. For revealing the underlying disaster-causing mechanism of wind-induced galloping of the iced conductor,this paper has studied the variation of the negative aerodynamic damping in the wind speeds based by two-way coupling CFD numerical simulations. The results show that the crescent iced conductor would not generate a negative aerodynamic damping in the transverse direction and would induce the negative aerodynamic damping in the vertical and torsional directions. When the negative aerodynamic damping is bigger than the structuralinherent damping,the iced conductor will gallop in the corresponding directions. The further investigation indicates when the iced conductor vibration diverges in vertical and torsional directions,the wind attack angle will change,which will cause a variation in the vertical aerodynamic damping and torsional aerodynamic damping. With a balance between the negative torsional aerodynamic damping and inherent damping,and the torsional vibration response will gradually develop to be stable.