利用旋涡发生器减小大跨方形平屋盖风吸力的实验研究  

Experimental study on reducing wind suction of large-span sguare flat roof using passive vortex generators

作　　者：张洪福 刘婷婷 周蕾 ZHANG Hongfu;LIU Tingting;ZHOU Lei(School of Civil Engineering,Northeast Forestry University,Harbin 150040,China;Department of Civil and Environmental Engineering,Hong Kong University of Science and Technology,Hong Kong 999077,China)

机构地区：[1]东北林业大学土木工程学院,黑龙江哈尔滨150040 [2]香港科技大学土木与环境工程学院,中国香港999077

出　　处：《中南大学学报（自然科学版）》2023年第5期1839-1850,共12页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51908107)。

摘　　要：在强风作用下,屋盖作为风敏感部位往往最先发生破坏,如何抑制屋盖上的极值负风压是保障大跨建筑抗风安全的关键。基于此,提出一种简单有效的新型屋盖抗风气动措施。在平屋顶屋檐处安装旋涡发生器(PVG),通过旋涡发生器的扰流作用来减小屋盖极值风压。采用风洞测压试验研究在不同风向角下PVG对屋面极值风压的气动控制效果,分析PVG对屋顶流场结构的影响并探讨PVG的工作机理。研究结果表明:PVG可以有效减小平屋盖屋面极值风压,尤其在倾斜风向角下的减压效果显著。在最不利风向角下,屋盖极值风压最大减小幅度可达73.3%。相对于长度来说,PVG高度对屋面风压的影响更明显,较密的安装间距和适宜的安装角度可以更好地降低屋盖风吸力。在安装PVG后,屋盖锥形旋涡的涡核位置和再附位置发生改变,屋顶风压低频部分能量占比大幅度减少,脉动能量减弱,大尺度旋涡减少,而小尺度的湍流造成的脉动能量成分增加。The roof,as a wind-sensitive part,is often the first to suffer damages during strong wind events.How to mitigate the extreme negative wind pressure on the roof is the key to ensure the safety of the buildings.Consequently,a simple-effective new device,passive vortex generators(PVG),to mitigate extreme wind pressure was proposed.By the disturbing effect of the PVGs,they were installed at the eaves of flat roofs to reduce the roof extreme wind pressure.The aerodynamic control effects of PVGs on roof extreme wind pressure were presented at different wind angles.The effects of PVGs on flow field as well as their control mechanism were analyzed and discussed.The results show that the PVGs can effectively reduce the wind pressure on the flat roof,particularly at nonzero wind angles.At the most unfavorable wind angle,the maximum reduction in roof extreme wind pressure can be up to 73.3%.Compared with the length,the PVG height has a more obvious effect on mitigating the roof suction.A denser installed spacing and a suitable installed angle can better reduce the roof wind pressure.After installing the PVGs,the position of the vortex core and the reattachment position of the conical vortex are highly modified.The low-frequency portion of the wind pressure fluctuation energy is significantly reduced,and the total fluctuation energy is weakened.The large-scale vortices are then reduced,while the small-scale turbulence component is increased.

关 键 词：平屋盖 大跨建筑 风洞试验 极值风压 旋涡发生器 

分 类 号：TU352.2[建筑科学—结构工程]