雷暴冲击风作用下高层建筑风压频域特性  

Frequency domain characteristics of wind pressure on a high-rise building under thunderstorm downburst

作　　者：方智远 汪之松[1,2] 李正良[1,2] FANG Zhiyuan;WANG Zhisong;LI Zhengliang(School of Civil Engineering,Chongqing University,Chongqing 400045,China;Key Laboratory of New Technology for Construction of Cities in Mountain Area,Ministry of Education,Chongqing University,Chongqing 400045,China)

机构地区：[1]重庆大学土木工程学院,重庆400045 [2]重庆大学山地城镇建设与新技术教育部重点实验室,重庆400045

出　　处：《振动与冲击》2020年第7期51-58,73,共9页Journal of Vibration and Shock

基　　金：国家自然科学基金(51208537)。

摘　　要：为研究雷暴冲击风作用下高层建筑风压的频域特性,采用冲击射流装置模拟雷暴冲击风,对矩形高层建筑模型进行测压试验。根据试验数据,对模型表面的脉动风压系数功率谱、水平和竖向相关系数、水平及竖向相干函数进行了详细分析,讨论了模型所在径向位置对脉动风压频域特性的影响。结果表明:各径向位置处模型迎风面的脉动风压功率谱与来流脉动风速谱基本一致;侧面与背风面脉动风压的能量主要集中在旋涡脱落频率处;风压相关性随测点间距离的增大而减小;迎风面风压的水平和竖向相干性均较强,脉动风压同步性较好;侧面测点风压水平相干性在折减频率小于0.2时较为显著,竖向相干性在整个频率范围内相对较好;背风面测点风压的水平和竖向相干性在折减频率小于0.1时较好,随着折减频率增大,相干性迅速减弱;迎、背风面中心测点风压在折减频率0.06附近存在较强的水平相干性,相位角相差180°左右,脉动风压呈现相反的相位特征。In order to study frequency domain characteristics of wind pressure on a high-rise building under thunderstorm downburst,an impinging jet device was used to simulate thunderstorm downburst,and pressure tests were conducted on a rectangular high-rise building model under simulated thunderstorm downburst.According to test data,power spectral density,correlation coefficients in horizontal and vertical directions and coherence functions in horizontal and vertical ones of fluctuating wind pressure were analyzed in detail.Effects of radial position of the model on fluctuating wind pressure’s frequency domain characteristics were discussed.The results showed that power spectral density of fluctuating wind pressure on the model’s windward surface at radial position is basically consistent to that of incoming flow wind speed spectrum;energy of fluctuating wind pressure on sides and leeward one is mainly concentrated at vortex shedding frequencies;correlation of wind pressures decreases with increase in distance between measured points;coherences in horizontal and vertical directions of wind pressures on windward side are stronger,and synchronization of fluctuating wind pressures is better;horizontal coherence of wind pressure on sides is more significant when the reduction frequency is less than 0.2,and its vertical coherence is relatively better within the whole frequency range;coherences in horizontal and vertical directions of wind pressure on leeward side are stronger when the reduction frequency is less than 0.1,and coherence quickly weakens with increase in the reduction frequency;there is a stronger horizontal coherence between wind pressures on windward side and leeward one near the reduction frequency of 0.06;when phase angle difference is about 180°,fluctuating wind pressure reveals the opposite phase characteristics.

关 键 词：雷暴冲击风 冲击射流 高层建筑 功率谱 相干函数 

分 类 号：TU312.1[建筑科学—结构工程]