城市街道峡谷二维空气流场的数值计算

用标准κ-ε模型计算了不同高宽比街道峡谷的内部流场,并将计算结果与风洞试验数据及前人的雷诺应力湍流模型研究结果进行了对比.计算表明:随着高宽比的增加,峡谷内旋涡数增多,易形成独立的稳定的循环气流,污染物会比较难扩散.峡谷内建筑物墙面附近气流垂直速度的曲线上有驻点出现,峡谷达到一定深度后,并开始出现第2个驻点.

Numerical Study of Airflow Fields in Street Canyons

Based on the standard κ-εturbulence model,airflow fields within street canyons under different building heights to street width ratio were simulated.This model was validated against Reynolds stress roodel and wind tunnel results.The numerical simulation results show that the aspect ratio of the street canyons has significant effects on inner airflow fields.With the increase of the building height to street width ratio,the number of vortices increase and the pollutants are difficult to disperse.There is an obvious stagnation point on the wall surface of canyon interior.The second stagnation point will appear after the depth reaches a certain value.