摘要
采用Fluent软件对7种不同建筑物偏移量Δy(Δy=0、1/6 W、1/3 W、1/2 W、2/3 W、5/6 W和W,其中:W为街道宽度)下的交叉口内气流和污染扩散进行了三维数值模拟.模拟结果表明,建筑物偏移量对交叉口内气流运动和污染扩散具有显著影响.1/6 W的偏移量已足以在侧向街道内产生明显的次生流;当偏移量由1/6 W增加到1/3 W时,侧向街道内的速度场显著增强;而当偏移量分别为1/2 W、2/3 W、5/6 W和W时,侧向街道内的风速已与上风街道内的风速相当.随偏移量的增加,侧向街道和交叉口的空气交换增强而下风街道与交叉口的空气交换减弱.随着偏移量的增加,从上风街道尾端点源扩散到侧向街道内的污染物增加.
3-D numerical simulation was performed using Fluent software to evaluate the airflow and pollutant dispersion in a street intersection under seven different building offsets ofΔy=0,1/6 W,1/3 W,1/2 W,2/3 W,5/6 W and W.The results revealed clearly that the airflow and pollutant dispersion in a street intersection were influenced significantly by the building offset.The offset of 1/6 W was sufficient to develop the secondary flow well in the lateral streets.As the offset increased from1/6 W to 1/3 W,the velocity fields in the lateral streets were strengthened significantly.In the cases with the offset of 1/2 W,2/3 W,5/6 W and W,the wind velocity in the lateral streets was comparable with that in the upwind street.The velocity field in the downwind street became weaker as the offset increased.As the offset increased,the air exchange betweenthe lateral streets and the intersection was strengthened while the air exchange was weakened between the intersection and the downwind street.As the offset increased,more pollutants were transported into the lateral streets from the point source,which situated at the end of the upwind street.
作者
黄远东
刘泽宇
许璇
HUANG Yuandong LIU Zeyu XU Xuan(School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093, Chin)
出处
《能源研究与信息》
2017年第3期132-137,共6页
Energy Research and Information
关键词
气流
污染扩散
建筑物偏移
街道交叉口
数值模拟
airflow
pollutant dispersion
building offset
street intersection
numerical simulation
