架空建筑街谷内流动与污染物扩散的数值模拟研究

研究架空建筑设计对街道峡谷内气流流动和污染物扩散规律的影响。考虑了4种不同街谷高宽比(H/W)和3种架空建筑类型,利用经风洞实验验证的CFD数值模型对上述街谷内流动与污染物扩散规律进行模拟研究。结果表明,在无架空街谷中,H/W的增大不利于街谷内污染物扩散。与无架空街谷相比,架空结构显著改善了街谷内的空气质量。两侧建筑架空结构比单侧建筑架空结构更有利于街谷内污染物扩散,上游建筑架空结构对街谷内污染物的稀释作用优于下游建筑架空结构。当两侧建筑架空时,街谷内污染物可降低90%以上。架空结构显著增强了街谷近地面的气流流速,改善了街谷内的空气质量。

Numerical simulation studies on airflow and pollutant dispersion in street canyons with void decks

To explore the influence of the structure of buildings with void decks on the airflow and pollutant dispersion in street canyons, CFD (computational fluid dynamics) numerical models validated by the wind-tunnel tests were employed by considering four aspect ratios (H/W) and three configurations of buildings with void decks. The results show that the increase of H/W is not conducive to the dispersion of pollutants in the street canyon without any void decks. Compared with the street canyon without any void decks, the structures of building with void decks observable improves the air quality in street canyons. The structure of buildings with void decks on both sides is more propitious to the dispersion of pollutants in the street canyon than the structure of building with a void deck on one side, and the dilution effect of the structure of upstream building with a void deck on the pollutants in the street canyon is better than that of the structure of downstream building with a void deck. The pollutant concentration in the street canyon with void decks at buildings on both sides is reduced by more than 90%. Therefore, the structures of buildings with void decks significantly enhances the airflow in the area near the ground and improves the air quality in street canyons.