Near surface wind longitudinal velocity positively skews with increasing aerodynamic roughness length
Near surface wind longitudinal velocity positively skews with increasing aerodynamic roughness length
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DOI：
10.1016/j.jweia.2017.06.007
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发表时间：
2017-10-01
影响因子：
4.8
通讯作者：
Masters, F. J.
中科院分区：
文献类型：
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作者：
Fernandez-Caban, P. L.;Masters, F. J.
1999-2016年大西洋飓风季节的风速观测和边界层风洞（BLWT）测量结果表明，随着表面粗糙度的增加，近地面风的行为偏离高斯分布。雷诺兹应力的象限分析清楚地表明，在强风中，纵向偏度和向下的动量转移（横扫事件）之间存在联系，这也是以前的研究所观察到的。尽管典型风洞发展段的实验配置可以正确地模拟这种现象，但现代风荷载配置和BLWT相似性要求并没有明确地考虑到这种影响。在这里，我们量化了观测到的正偏度如何影响ASCE 7的地形暴露系数剖面。结果表明，需要更新峰值因子计算，以准确预测在建筑地形中作用于低层建筑的极端风。
Analysis of anemometric observations collected during the 1999-2016 Atlantic hurricane seasons and boundary layer wind tunnel (BLWT) measurements indicate that the near surface wind behavior deviates from Gaussian as surface roughness increases. Quadrant analysis of the Reynolds stress clearly demonstrates the linkage between the longitudinal skewness and downward transfers of momentum (sweep events) in strong winds, which previous studies have also observed. Modern wind load provisioning and BLWT similarity requirements do not explicitly account for this effect, although the experimental configuration of typical wind tunnel development sections may correctly simulate the phenomena. Here we quantify how the observed positive skewness affects the terrain exposure coefficient profile for ASCE 7. The results demonstrate the need to update peak factor calculations to accurately predict extreme winds acting on low-rise buildings in built-up terrain.