矩形高层建筑表面风压特性研究  

Wind pressure characteristics on a high-rise building with rectangular section

作　　者：董欣[1] 赵昕[1,2] 丁洁民[1,2] 庄翔[2] 

机构地区：[1]同济大学建筑设计研究院(集团)有限公司,上海200092 [2]同济大学土木工程学院建筑工程系,上海200092

出　　处：《建筑结构学报》2016年第10期116-124,共9页Journal of Building Structures

基　　金：国家自然科学基金青年基金项目(51408353);上海市青年科技启明星计划(15QB1404800)

摘　　要：通过刚性模型风洞测压试验,对短边迎风和长边迎风时的矩形截面高层建筑表面风压特性及作用机理进行研究。对比了不同风向角下建筑表面风压分布及相关特性:短边迎风时,锥形涡是建筑侧面风压脉动的主要诱因,侧面脉动风压较大值出现在底边缘附近的瓣状区域内,该区域内风压互相关性显著;长边迎风时,旋涡脱落是导致建筑侧面风压脉动的主要因素,侧面吸力较大值集中在迎风前缘附近,且风压横向互相关性突出。基于风压时程的高阶矩,探讨了建筑表面风压非高斯脉动特性:短边迎风时,风压非高斯区位于迎风面角部、锥形涡作用区及尾流作用区;长边迎风时,非高斯区位于侧面迎风前缘附近的分离区。分析了建筑侧面脉动风压谱和风压相干性,结果表明:短边迎风时,建筑侧面风压脉动能量主要集中在低频段,风压强相干区域仅存在于迎风前缘附近;长边迎风时,旋涡脱落使得建筑侧面脉动风压谱和风压横向相干函数均在折减频率0.1处出现峰值,加之该频率所对应相位角接近0°,使得建筑侧面出现强烈且同步的风压脉动;短边迎风和长边迎风时锥形涡及旋涡脱落在建筑两侧诱导产生的风压脉动均为反相位,对结构抗风较为不利。Based on the wind tunnel test,the characteristics and mechanism of wind pressure on a high rise building with rectangular section are researched under two different wind directions. Firstly, the wind pressure and its correlation properties are analyzed. When the flow is normal to the short edge,larger and highly correlated fluctuating suctions on the side face are located on a petal inclined at an angle of 60°. When the flow is normal to the long edge,greater suctions are observed near the leading edge. The transverse correlations of pressure fluctuations are significant on the side face. Secondly,the non-Gaussian feature of wind pressures is indentified through higher order moments.Wind pressures on windward corners,the conical vortex region,and the leeward side influenced by the wake are nonGaussian when the narrow face is windward. In contrast,the non-Gaussian region is located near the leading edge when the flow is normal to the wide face. Thirdly,the wind spectrum and chordwise coherence function on the side face are discussed. When the narrow face is windward,the spectrum energy is concentrated on the low frequency range. Higher coherence is recognized near the leading edge. When the wide face is windward,vortex shedding is the main cause of fluctuations on the side faces. Peaks corresponding to reduced frequency of 0. 1 are observed in the wind spectrum and chordwise coherence functions. Because of the phase corresponding to the peak frequency 0. 1 is near0°,the pressure fluctuations are detected to be strong and synchronous. Moreover,the pressure fluctuations on the two side faces are out of phase under the influence of conical vortices and vortex shedding,which is adverse to the wind resistant design of high rise buildings.

关 键 词：高层建筑 矩形截面 风压特性 锥形涡 旋涡脱落 

分 类 号：TU973.213[建筑科学—结构工程]