下击暴流风场的大气边界层风洞模拟研究  

Experimental study on simulation of downburst in atmospheric boundary layer wind tunnel

作　　者：段旻[1] 谢壮宁[2] 石碧青[1] 

机构地区：[1]汕头大学土木工程系,广东汕头515063 [2]华南理工大学亚热带建筑科学国家重点实验室,广东广州510641

出　　处：《建筑结构学报》2012年第3期126-131,共6页Journal of Building Structures

基　　金：国家自然科学基金项目(50778108);国家科技支撑计划项目(2006BAJ06B05-3)

摘　　要：使用可调导流板、挡板和粗糙元,在大气边界层风洞内实现了对1∶300和1∶600两种流场比例下击暴流风场的模拟,并与经典的理论剖面进行对比,对模型区域范围内风场的水平和竖向风速分布进行了较为详细的考察,在此基础上研究了一大跨度圆柱形屋盖在所模拟的下击暴流风场的风压系数分布特征,并与GB 50009—2001的B类地貌风场的结果进行比较。结果显示,所模拟的两种比例的下击暴流水平风剖面与理论值吻合较好,模拟出的下击暴流的竖向风剖面在一定高度范围内与水平风剖面有着相似的分布规律,且在模型区域具有较好的稳定性。圆柱形屋盖模型的试验结果表明,该屋盖在下击暴流风场测得的平均风压系数分布和B类地貌风场的结果非常接近,但极值风压系数小于B类地貌风场的试验结果。Two downburst wind fields with scales of 1 ： 300 and 1 ： 600 were simulated using adjustable guide vane, baffler and roughness elements in an atmospheric boundary layer wind tunnel. The simulated wind velocity profiles were compared with the empirical models and the structure of the wind fields were measured and investigated in detail. The wind pressure coefficient distributions on a large span cylindrical roof structure were tested in the simulated downburst wind field and compared with the results tested in field of exposure category B defined in GB 50009--2001. The results show that the horizontal velocities profiles of simulated downburst agree well with the empirical curves. The simulated profiles of vertical and horizontal velocities have the similar tendency and have good stability within the building model region. The tested mean wind pressure coefficient on the cylindrical roof in downburst is very close to that in exposure category B. However, the extreme wind pressure coefficient in downburst is less than that in exposure category B.

关 键 词：下击暴流 风洞试验 风场模拟 大跨结构 风荷载 

分 类 号：O357.43[理学—流体力学] TU393.3[理学—力学]