台风环境下冷却塔风致振动的案例研究

Case Study of Wind-Induced Vibration of a Cooling Tower Under Typhoon Environment

冷却塔是风敏感结构,其高度的增加使得抗风问题更加突出,尤其是在台风地区。本文采用主动风洞技术模拟了场地为B类粗糙度的良态风和台风风场,进行了某超大型冷却塔的刚性测压和气动弹性测振试验,系统地研究了良态风和台风场下塔筒壳体抗风性能。对塔筒喉部位置迎风点、峰值吸力点、分离点和背风点处所对应壳体的风压系数、峰值因子、功率谱密度和动力放大系数进行综合研究。研究发现:台风场下塔筒环向风压和风致响应存在更加明显的非高斯特征;同时共振响应占比更高,结构的动力放大因子最大值达到良态风作用下的1.18倍。本文的研究结果可作为台风地区超大型冷却塔抗风设计的参考。

As high-rise cooling towers are constantly emerging,wind effects on this kind of wind-sensitive structures have attracted more and more attention,especially in typhoon prone areas.Terrain Type B turbulent flow fields under the normal wind and typhoon are simulated by active wind tunnel technology,and rigid-pressure-measurement model and aero-elastic-vibration-measurement model of a large cooling tower are built.The stagnation point,peak suction point,separation point and leeward point of the throat position shell are selected to analyze pressure coefficient,probability distribution,peak factor,power spectral density and dynamic amplification factor under normal wind and typhoon.It is clarified that there exists a significant non-Gaussian characteristic under typhoon condition,which also exists in structural response level.Resonance response ratio of the total response is higher during typhoon condition.The maximum value of dynamic amplification coefficient under typhoon field is up to 1.18 times over that under normal wind.The findings of this study are expected to be of interest and practical use to professional and researchers involved in the wind-resistant designs of super-large cooling towers in typhoon prone regions.