居住区底层架空设计对风环境影响研究

EFFECT ON WIND ENVIRONMENT OF PILOTI DESIGN IN RESIDENTIAL COMMUNITY

底层架空设计不但能有效改善室外风环境,还可创建避免太阳直射的室外活动空间,在热带和亚热带地区被广泛采用,系统研究架空设计的风环境影响对基于环境优化的居住区设计具有一定参考价值。本研究以广州市为例,采用结合非稳态放射计算的CFD耦合模拟方法,对不同架空率下居住组团的风速平均值和累积度数展开对比研究。研究结果显示,在非架空区域,随着底层架空率的增加,低风速累积分布比例逐渐缩减,当底层架空率超过60%时,平均风速增长率出现拐点,增速加快;在架空区,随着架空率的提升风环境有明显改善,当架空率达到80%时,平均风速增长率出现拐点,增速放缓。值得注意的是,架空率较低时,其改善架空区风环境的能力有限,当架空率为40%时,架空区风速均低于0.3m/s。

First floor piloti design can not only optimize the outdoor wind environment, but also create activity spaces which avoid the direct radiation from the sun, which is commonly used in building design in tropical and subtropical climate zones. Taking the city of Guangzhou as an example, by adopting a coupled CFD simulation method, this research firstly designed a series of cases, and then compared the mean wind velocity and cumulative values of the simulation results. The results showed that, for those areas out of piloti, cumulative values of low wind velocity decreased with the increase of piloti ratio, and the inflection point appears at 60 percent piloti ratio for the mean wind velocity(increase trend to be faster after inflection point). For the areas under piloti, the wind environment was highly optimized by the increase of piloti ratio, and the inflection point appears at 80 percent piloti ratio for the mean wind velocity(increase trend to be slower after inflection point). It was noticed that, the very low piloti ratio contributes little to the wind environment under piloti areas, for example, all wind velocity under piloti areas are lower than 0.3 m/s when piloti ratio is 40 percent.