风嘴几何参数对双边箱式Π型梁涡振性能的影响  

Effect of Geometric Parameters of Wind Fairing on Vortex-induced Vibration Performance of Two-side Box TypeΠ-shaped Girder

作　　者：李加武[1,2] 徐敏建 王子健 邢松 LI Jia-wu;XU Min-jian;WANG Zi-jian;XING Song(School of Highway,Chang an University,Xi an 710064,Shaanxi,China;Wind Tunnel Laboratory,Chang an University,Xi an 710064,Shaanxi,China;North China Municipal Engineering Design&Research Institute Co.,Ltd.,Tianjin 300074,China)

机构地区：[1]长安大学公路学院,陕西西安710064 [2]长安大学风洞实验室,陕西西安710064 [3]中国市政工程华北设计研究总院有限公司,天津300074

出　　处：《建筑科学与工程学报》2022年第5期74-83,共10页Journal of Architecture and Civil Engineering

基　　金：国家自然科学基金项目(5197807)。

摘　　要：为研究风嘴几何参数对双边箱式Π型梁涡振性能的影响,设计了包括原断面在内的4类试验组合,共计14种试验工况,通过节段模型测振试验,测得不同工况下Π型梁涡振振幅随试验风速的变化,分析了0°风攻角下不同风嘴长度和尖端高度对双边箱式Π型梁涡振振幅、锁定区间长度和起振风速的影响。采用SST k-ω模型进行计算流体力学分析,模拟了原断面和不同风嘴措施下双边箱式Π型梁断面周围的流场特性,结合静态绕流涡量演化图探讨了不同风嘴措施的涡振抑制机理。结果表明:多数风嘴措施能有效抑制双边箱式Π型梁的竖弯涡振,同时降低其扭转涡振振幅;尖端高度与梁高之比为5/6时,该Π型梁的涡激共振被完全抑制,涡振性能表现良好;增大风嘴长度和令风嘴尖端朝下有助于减小断面的涡振振幅和锁定区间长度,提高起振风速,对该Π型梁的抑振效果更显著;双边箱式Π型梁原断面涡激共振明显,安装风嘴能减弱上表面气体的流动分离,减小漩涡尺度,有利于抑制涡振;双边箱式Π型梁下表面周期性脱落并移动的漩涡是其扭转涡振的驱动性因素。In order to study the effect of geometric parameters of wind fairing on vortex-induced vibration(VIV)performance of two-side box typeΠ-shaped girder,4 types of test combinations including the original section,which contain 14 test conditions were carried out.Through the segmental model vibration measurement test,the VIV amplitude ofΠ-shaped girder with test wind speed under different conditions were measured.The effects of different wind fairing lengths and tip heights on the VIV amplitude,the lock-in length and starting wind speed of two-side box typeΠ-shaped girder at 0°wind attack angle were analyzed.The SST k-ωmodel was used for computational fluid dynamics analysis.The flow field characteristics around the section of two-side box typeΠ-shaped girder under the original section and different wind fairing were simulated,and the VIV suppression mechanism of different wind fairing measures was discussed based on the evolution chart of static vorticity around flow.The results show that most wind fairing measures can effectively suppress the vertical bending VIV and reduce the torsional VIV amplitude of the two-side box typeΠ-shaped girder.When the ratio of tip height to girder height is 5/6,the vortex-induced vibration of theΠ-shaped girder is completely suppressed and the VIV performance is good.Increasing the length of wind fairing and making the tip of wind fairing downward can help to reduce the VIV amplitude of the section and the lock-in length,and improve the starting wind speed,which can make the vibration suppression effect on theΠ-shaped girder more obvious.The vortex-induced vibration is obvious in the original cross section of two-side box typeΠ-shaped girder.Installation of wind fairing can weaken the flow separation of upper surface gas and reduce the vortex scale,which is beneficial to suppress VIV.Periodic shedding and moving vortices on the lower surface of two-side box typeΠ-shaped girder are the driving factors of torsional vortex-induced vibration.

关 键 词：结构风工程 双边箱式Π型梁 涡激共振 风嘴形式 风洞试验 数值模拟 

分 类 号：TU311.3[建筑科学—结构工程]