不同长宽比矩形高层建筑的横风向风力特性  

Characteristics of across-wind force of rectangular high-rise buildings with different side ratios

作　　者：袁家辉 陈水福[1] 刘奕[1] YUAN Jiahui;CHEN Shuifu;LIU Yi(College of Civil Engineering and Architecture,Zhejiang University,Hangzhou 310058,China)

机构地区：[1]浙江大学建筑工程学院,浙江杭州310058

出　　处：《中南大学学报（自然科学版）》2021年第12期4361-4371,共11页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51878607)

摘　　要：为探讨长宽比和地貌类别对矩形高层建筑横风向风力特性的影响,对具有较大范围长宽比的矩形高层建筑在4种风场条件下进行了同步测压风洞试验。首先,基于试验结果分析了不同风场条件下、不同长宽比矩形高层建筑横风向风力系数均方根随高度的变化;然后,通过最小二乘法拟合得到了以地貌类别和长宽比为基本变量,适用于长宽比为1/9~9的矩形高层建筑升力系数均方根的闭合表达式;最后,考察了长宽比、风向角和地貌类别对升力系数功率谱密度的影响。研究结果表明:对于较大长宽比的建筑,升力系数均方根沿高度呈现先增大后减小,最后在建筑顶部附近又转而增大的变化规律;从升力系数功率谱密度角度看,正交风向下随着长宽比增大,横风向风力功率谱密度能量呈现从高频向低频转移的趋势,功率谱谱峰先增大后减小,带宽先减小后增大;对于大长宽比矩形高层建筑升力系数功率谱密度,正交风向不再是控制风向,在斜风作用下,功率谱密度能量具有向高频转移的倾向。本文获得的多项式拟合公式可较准确地预测不同长宽比和不同风场条件下矩形高层建筑的升力系数均方根。To investigate the effects of side ratio and terrain category on characteristics of across-wind force of rectangular high-rise buildings,synchronization pressure wind tunnel tests for high-rise buildings with a wide range of side ratios in four terrain categories were conducted.Firstly,the variation of root mean square(RMS)of across-wind force coefficient with height for rectangular high-rise buildings with different side ratios in various terrain categories was analyzed based on the experimental results.Secondly,closed-form formulas with side ratio and terrain category as basic variables for the RMS of lift force coefficient of rectangular high-rise buildings with side ratios of 1/9~9 were obtained by fitting with the least square method.Finally,the effects of side ratio,wind direction angle and terrain category on the power spectral density(PSD)of lift coefficient were evaluated.The results show that for buildings with a large side ratio,the RMS of lift coefficient increases firstly and then decreases along the height,and finally increases near the top of the building.In the view of lift coefficient PSD,the across-wind power spectrum energy shifts from high frequency to low frequency with the increase of side ratio in orthogonal wind direction.The PSD peak value increases firstly and then decreases,while the band width decreases firstly and then increases.For the lift coefficient PSD of rectangular high-rise buildings with a large side ratio,the orthogonal wind direction is no longer the control direction.Under the action of oblique wind,the PSD energy tends to transfer to high frequency.The fitted formulas in polynomial function form obtained in this paper can be used to accurately predict the RMS of lift force coefficients of rectangular high-rise buildings with different side ratios in various terrain categories.

关 键 词：矩形高层建筑 长宽比 风场类别 风洞试验 横风向 功率谱密度 

分 类 号：TU312[建筑科学—结构工程]