洞口设置对高层建筑静力风荷载的影响研究

Research on the influence of openings to static wind load of highrise buildings

本文对涉及两种开洞率、三种不同开洞位置和全封闭(无洞口)的八个高层建筑刚性模型的表面平均风压分布进行了风洞试验研究,并与计算流体动力学(CFD)大型商业软件Fluent6.0的计算结果进行了对比分析。结果表明,开洞建筑平均风压的减少主要是受荷面积减少引起的,但其减少的比率大于开洞率。此外,借助Fluent6.0对不同开洞率情况下的建筑模型进行了大量算例分析,得到了中部开洞建筑模型的平均风压系数相对值和基底弯矩系数相对值与开洞率之间的相关方程;探讨了底部开洞建筑模型洞内平均风速的增大效应与洞口大小、来流方向之间的关系。分析表明,在最不利来流风向角情况下,洞中最大平均风速可超过建筑模型顶部的远处来流风速,应引起建筑风环境设计者的关注。

Mean wind induced pressure distributions on every surface of eight rigid highrise building models, including two kinds of opening ratios, three different opening locations and two totally enclosed (without opening) models, were investigated by wind tunnel tests. Comparing the test results with the computational results by the commercial computational fluid dynamics (CFD) software Fluent 6.0, it indicated that the primary factor for the reduction of overall wind load onto building models with an opening was the decrease of surface area due to opening, but the reduction ratio of the wind load was greater than the opening ratio. Furthermore, with the aid of Fluent 6.0, a large number of building models with various opening ratios were analyzed. The interaction equations between the relative coefficients of mean wind induced pressure or wind induced base moments and the opening ratios were obtained in mid opening building models. The relation between opening dimension or wind direction and the mean wind velocity increase in the hole of building models with bottom opening was also explored. In the worst wind incidence, the biggest mean wind velocity in the bottom hole could exceed the undisturbed inflow velocity corresponding to the top of building model, which should be paid close attention to, for the designers of building wind environment.