几何特征对柱面屋盖雷诺数转捩区间影响的风洞试验研究  

Research on effects of geometric characteristics on critical Reynolds number ranges of cylindrical roofs in wind tunnel

作　　者：孙瑛[1,2] 邱冶[3] 武岳[1,2] 

机构地区：[1]哈尔滨工业大学结构工程灾变与控制教育部重点实验室,黑龙江哈尔滨150090 [2]哈尔滨工业大学土木工程学院,黑龙江哈尔滨150090 [3]河海大学土木与交通学院,江苏南京210098

出　　处：《建筑结构学报》2016年第12期10-19,共10页Journal of Building Structures

基　　金：国家自然科学基金面上项目(51278160;51478155;51378147)

摘　　要：大跨度柱面屋盖结构的风荷载特性具有明显的雷诺数效应，其屋盖几何特征对风荷载雷诺数效应影响较大。为此，以柱面屋盖为研究对象，开展了考虑几何特征影响的雷诺数效应风洞试验，变化几何特征参数包括矢跨比（f/L为1/6~1/2）和长跨比（B/L为1~12），试验雷诺数Re范围为6.90×10^4~1.38×10^6。基于风洞试验数据，分析了模型表面风压分布规律、压力梯度和升阻力曲线等。研究结果表明：柱面屋盖长跨比减小、矢跨比增大会使雷诺数转捩区间的下限值向高雷诺数范围转移，即三维绕流效应使得分离边界层出现转捩滞后现象；当模型长跨比B/L由12减小至1时，雷诺数转捩区间下限值从1.66×10^5逐渐增大至4.14×10^5；当矢跨比f/L由1/3增加至1/2时，转捩区间下限值则从2.48×10^5增大至4.14×10^5；对矢跨比1/6屋盖模型，在试验雷诺数（6.90×10^4~2.48×10^5）范围内无明显雷诺数效应。There is a strong dependence of aerodynamic loads for large-span cylindrical roofs on Reynolds number effect, and the Reynolds number sensitivities are greatly influenced by the geometric characteristics of the roofs. As a result, based on the series of Reynolds number tests of cylindrical roof model, the influences of geometric parameters on the Reynolds number effects were investigated. Different rise to span ratios （f/L was from 1/6 to 1/2） and width to span ratios （B/L was from I to 12） were considered, and the Reynolds numbers ranged from 6.90 × 10^4 to 1.38 × 10^6. Based on the data derived from wind tunnel tests, the wind pressure distributions, pressure gradients and lift and drag force coefficients were analyzed. The test results show that there is a direct shift of the transitional Reynolds number towards high Re level owing to the increasing rise to span ratio, whilst the decreasing length to span ratio. This reveals that three-dimensional flow will postpone the transition of separated shear layers from laminar to turbulent over the roof surface. The lower limits of critical Reynolds number increases from 1.66 × 10^5 to 4. 14 × 10^5with B/L decreasing from 12 to 1, whilst the lower limits increases from 2. 48 × 10^5 to 4. 14 × 10^5 withf/L increasing from 1/3 to 1/2. There is no Reynolds number effect for cylinder roofs with f/L of 1/6 in the range of test Reynolds number from 6. 9 × 10^4 to 2. 48 × 10^5.

关 键 词：柱面屋盖 几何特征 风洞试验 雷诺数效应 风荷载 

分 类 号：TU393.303[建筑科学—结构工程] TU312.1