Characteristics of aerodynamic forces and pressures on square plan buildings with height variations
Characteristics of aerodynamic forces and pressures on square plan buildings with height variations
复制标题
DOI：
10.1016/j.jweia.2010.02.004
复制
发表时间：
2010-08-01
影响因子：
4.8
通讯作者：
Kanda, Jun
中科院分区：
文献类型：
--
作者：
Kim, Yongchul;Kanda, Jun
关于降低高层建筑侧风响应的研究较多，主要集中在角形的影响上。沿高度方向通过变细或后退等方式改变截面可以减小高层建筑的侧风响应。为了研究气动力减小的机理，进行了脉动压力和脉动力的风洞试验。在代表郊区和城市流动状况的两种典型边界层下，分别采用了锥度比为5%和10%的两种模型、一种背置模型和一种边比为一的方形棱柱原型模型。结果表明，锥形或回调有助于减小平均阻力和波动升力。减速比随锥度比的增大而增大，且在相同表面积下，设置后置模型比锥度模型更有效地减小了波动升力，在近郊流动条件下，减小系数约为40%。而侧面风压功率谱的变细和回缩使其变为宽带，且峰值频率依赖于高度，使得Strouhal分量附近的相关性较低甚至为负。(C) 2010 Elsevier Ltd.版权所有。
Many studies on reducing across-wind responses of tall buildings have been investigated, mainly focusing on the effect of corner shape. And it is also known that changing section along the height through tapering or set-back could reduce across-wind responses of tall buildings. In this paper, to investigate the mechanism of aerodynamic force reduction, the wind tunnel tests for fluctuating pressure and fluctuating force were carried out. Two models with different tapering ratio of 5% and 10%, one set-backed model and one prototype square prism with side ratio of unity were employed under two typical boundary layers which represent suburban and urban flow condition. It is concluded that tapering or set-back helps to reduce the mean drag force and the fluctuating lift force. Reduction ratio increases as tapering ratio increases, and the set-backed model is more effective to reduce the fluctuating lift force than the tapered model with identical surface area, reducing the coefficients about 40% in suburban flow condition. And by tapering and set-back, the power spectra of wind pressures at sideward surface become wideband and the peak frequencies depend on height, which makes the correlation near the Strouhal component low or even negative. (C) 2010 Elsevier Ltd. All rights reserved.