摘要
该文基于相关现场实测和风洞试验结果,对强台风下带挑檐低矮双坡房屋气动荷载特性进行了大涡模拟(Large-eddy simulation,LES)研究。研究了台风脉动风场人工合成方法、近壁区网格划分策略及壁面边界条件等模拟参数对带挑檐双坡低矮房屋风荷载特性影响,定量分析利用大涡模拟预测强台风下低矮房屋屋面风压特性的可靠性,并基于大涡模拟全流场信息分析了低矮房屋周边钝体绕流瞬态特征。研究结果表明:基于CDRFG(Consistent discretizing random flow generation)人工合成湍流方法可以准确模拟具有高湍流度特性的台风风场,并通过先验的网格划分策略可以实现来流湍流自保持性。大涡模拟能够得到与现场实测及风洞试验较一致的平均和脉动风压系数,且极值风压系数在30%误差范围的可靠度达85%以上。迎风挑檐会导致屋面前缘流动分离提前发生,但对迎风前缘屋面风压分布规律影响较小。挑檐下缘形成的分离泡产生较大脉动吸力,挑檐局部净风压系数未显著增大。该文有助于进一步提升强台风下低矮房屋风荷载模拟的有效性,更加深入的掌握低矮房屋的风致破坏机理,为低矮房屋的抗风设计及抗风性能优化提供重要参考。
In comparison with the full-scale field measurements and its corresponding wind tunnel tests,this study numerically investigated the aerodynamic loadings on a gable roof of with eaves and double slopes during strong typhoons using Large-eddy simulation method(LESM).The effects of simulation parameters such as typhoon fluctuating wind field artificial synthesis method,near-wall meshing strategy and wall boundary conditions on the wind load characteristics of low-rise buildings with eaves are studied.The reliability of large eddy simulation to predict the wind pressure characteristics of low-rise buildings under strong typhoon is quantitatively analyzed,and the transient characteristics of flow around bluff bodies around low-rise buildings are analyzed by the grounds of the full flow field information of large eddy simulation.The results indicated that CDRFG(Consistent discretizing random flow generation)method could satisfactorily reproduce the highly turbulent typhoon wind field,and the self-turbulence could be simulated by the refined inflow region between the inlet and the place of interest according to the proposed prior grid meshing strategy.The large eddy simulation can obtain the average and fluctuating wind pressure coefficient which is consistent with the field measurement and wind tunnel test,and the reliability of the extreme wind pressure coefficient in the error range of 30%is more than 85%.The flow separation was earlier formed due to the windward roof overhang but resulted in trivial influences on the wind pressure distributions.The local net wind pressure coefficients on the roof overhang were observed to be consistent with the counterparts in the vicinity,which was resulted from the coupling effects between the cylindrical vortex on the upper surface of the roof overhang and local flow separation bubble beneath.The outcomes of this study would improve the confidence of LESM of aerodynamic loadings on low-rise buildings,boost our further understanding of the damage mechanism for wind-induced disast
作者
闫渤文
马晨燕
赵乐
杨庆山
YAN Bo-wen;MA Chen-yan;ZHAO Le;YANG Qing-shan(School of Civil Engineering,Chongqing University,Chongqing 400044,China;China Machinery International Engineering Design and Research Institute Co.,Ltd,Changsha,Hu’nan 410000,China;Beijing Jiaotong University,Beijing’s Key Laboratory of Structural Wind Engineering and Urban Wind Environment,Beijing 100044,China)
出处
《工程力学》
EI
CSCD
北大核心
2021年第11期66-78,133,共14页
Engineering Mechanics
基金
国家自然科学基金项目(51878104)
中央高校基本科研业务费专项资金项目(2020CDJQY-A062)
高等学校学科创新引智计划资助项目(B18062)
中国博士后科学基金项目(2018M631063)。
关键词
带挑檐低矮房屋
风荷载
强台风
大涡模拟
现场实测
风洞试验
low-rise building with roof overhang
wind effects
strong typhoon
large-eddy simulation
full-scale measurement
wind tunnel test
