摘要
为研究覆冰导线舞动时气动力的特性,从弱耦合角度出发,基于流体动力学仿真软件Fluent二次开发,利用用户自定义函数对导线的舞动轨迹进行编程并结合动网格技术实现流固耦合。计算了新月形覆冰导线在横向振动下的气动力系数,并与静态模拟结果和试验结果进行比较;分析了舞动幅值、频率和扭转振动对动态气动力的影响。结果表明:相同风速下,动态气动力系数大于静态值,二者具有相同的变化规律;阻力、升力系数随舞动幅值增大显著增加,特别是升力系数成倍增加;振动频率增加,也使动态气动力系数增大,但频率对动态气动力的影响小于幅值的影响;扭转振动对动态气动力有一定的影响。工程中采用静态气动力系数预测大档距舞动引起的断线的临界风速和塔承受的荷载,其结果不安全,应考虑动态气动力系数对舞动的影响。
In order to study the aerodynamic characteristics of galloping of iced conductor, based on software Fluent redevelopment, a user-defined function was introduced to describe the track of conductor galloping and the dynamic mesh technology was used to realize the fluid and solid coupling in accordance with a weakly coupled model. The aerodynamic coefficients of crescent iced conductor during lateral vibration were calculated, and compared with the results from simulation of the conductor in static state and also from experimental data. The effects of galloping amplitude, frequency and torsional vibration on the dynamic aerodynamic forces were analyzed. The results show that the dynamic aerodynamic coefficients are larger than the static ones, and they have the same variation trend under the same wind speed. Drag and lift coefficients increase significantly with the increase of galloping amplitude, especially the lift coefficient will be multiplied. The frequency increase also makes the dynamic aerodynamic coefficients increasing, but the effect of frequency on the dynamic aerodynamic force is less than that of amplitude. Torsional vibration has a certain influence on the dynamic aerodynamic force. When the static aerodynamic coefficients are used to forecast the critical wind speed of conductor break and the tower loads caused by large span galloping in engineering, the results tend to be unsafe. The effects of dynamic aerodynamic coefficients on galloping should not be ignored.
出处
《振动与冲击》
EI
CSCD
北大核心
2015年第7期209-214,共6页
Journal of Vibration and Shock
基金
天津市自然科学基金项目(11JCYBJC05800)
关键词
覆冰导线
动态气动力系数
舞动
数值模拟
iced conductor
dynamic aerodynamic coefficient
galloping
numerical simulation
