大深宽比矩形高层建筑表面脉动风压非高斯特性

Non-Gaussian features of fluctuating wind pressures on rectangular tall buildings with large side ratio

摘要:

为探究大深宽比矩形高层建筑表面脉动风压的非高斯特性,本文对深宽比为1/9~9的矩形高层建筑进行了同步测压风洞试验。基于试验结果,分析了建筑表面风压的三阶和四阶统计矩分布特性,对高层建筑各立面风压进行高斯与非高斯分布的分区；研究了风压的空间相关系数与非高斯性强度的关系,提出了一种新的估算建筑侧风面平均再附长度的计算方法。结果表明:在建筑侧风面上,脉动风压服从高斯还是非高斯分布取决于测点到迎风前缘的距离；除了以往文献指出的迎风面角部、侧风面分离区和背风面风压呈现非高斯性外,再附区后面的风压也呈现出高度的非高斯性；本文提出的相关系数法在计算平均再附长度时具有良好的准确性,利用该方法获得了矩形高层建筑侧风面的平均再附长度沿高度的变化呈抛物线形状。

Abstract:

To investigate the non-Gaussian features of fluctuating wind pressures on rectangular high-rise buildings with large side ratios, wind tunnel tests were conducted on scale models with side ratios ranging from 1/9 to 9. Based on the results, the third and fourth statistical moments of wind pressures on building surface were analyzed. Zones of Gaussian and non-Gaussian were classified for rectangular buildings with various side ratios. The relationship between spatial correlation coefficient of wind pressure and non-Gaussian intensity was studied and a new method for estimating the mean reattachment length at building side wall was proposed by evaluating the correlation coefficient of wind pressure. The results show that on the side wall, the non-Gaussian wind pressures are related to the distance from the leading edge. Apart from the non-Gaussianity in the corner of windward wall, separated flow regions of side wall and leeward wall noted by some literature, wind pressures behind the area where reattachment happens present non-Gaussian nature as well. The correlation coefficient method proposed in this paper has good accuracy in calculating the mean reattachment length, and the mean reattachment length calculated by the correlation coefficient method along the height changes in a parabolic shape.