雷暴冲击风作用下球壳型屋面模型风压特性试验研究  

Experimental investigation of spherical roof subjected to thunderstorm downbursts

作　　者：陈勇[1] 崔碧琪[1] 余世策[1] 楼文娟[1] 孙炳楠[1,2] 

机构地区：[1]浙江大学结构工程研究所,浙江杭州310058 [2]浙江大学宁波理工学院,浙江宁波315100

出　　处：《建筑结构学报》2011年第8期26-33,共8页Journal of Building Structures

基　　金：国家自然科学基金项目(50708096;20908208);国家科技支撑计划项目(2006BAJ01B07-04);浙江省自然科学基金项目(Y1110143)

摘　　要：以球壳型大跨度屋面为研究对象,进行雷暴冲击风作用下的刚性模型风洞试验。按照相似准则制作了不同类型球壳型屋面模型,利用射流装置、粗糙元等模拟了雷暴冲击风流场,研究了失跨比、高跨比及同一矢跨比下的跨度等结构参数以及屋面所处流场位置的变化对冲击风作用下屋面的风压极值位置及其数值大小、气流分离点位置等的影响。试验结果与CFD数值模拟结果的对比验证了试验装置及测试的可靠性。参数敏感性分析表明:球壳型屋面在风场中所处位置及屋面矢跨比对屋面表面正负风压的转变、极值风压位置及其数值等风压分布特征的影响较大;高跨比及一定范围内屋面跨度变化的影响主要体现在迎风面;屋面中心越接近射流中心,冲击风竖向风压的作用越明显。An experimental on the wind pressure distribution of a spherical-type long span roof under thunderstorm downbursts was studied.The scaled models were designed and manufactured according to the similarity criteria.The wind field of downbursts was simulated by utilizing an impinging jet to generate a flow blowing to a flat plate that has numerous roughness elements on its surface.The sensitivity studies of structural parameters such as height-to-span ratio,rise-to-span ratio,roof span,and the location of the roof in the tree-dimensional wind field were investigated by surveying the properties of the wind pressure,the location and magnitude of the extreme wind pressure,the position of flow separation point,etc.Comparisons of the results of experiments and those from computational fluid dynamics（CFD） analysis verified the reliability of the experimental facilities and tests.Parametric sensitivity analyses show that roof locations in wind field and the ratio of height to span have significant effects on the distribution and quantity of wind pressure,whereas the effects of the ratio of rise to span and roof span length of those surveyed in this paper are not quite apparent except for the windward roof face.The positive pressure will increase as the distance from the jet center reduces,whereas the negative pressure will reduce.This is due to the action of the vertical wind load in a downburst flow field.

关 键 词：球壳型屋面 雷暴冲击风 风洞试验 风压特性 

分 类 号：TU393.3[建筑科学—结构工程] TU317.1