【摘要】 街道峡谷结构和风向会对街道峡谷内的污染物浓度和扩散特征带来一定影响。利用计算流体力学(CFD)软件,针对街道峡谷高宽比、建筑物间隔(建筑物间空隙与街道总长度的比值)和风向对街道峡谷内细颗粒物扩散的影响进行数值模拟。模拟结果表明,建筑物间隔为20%,风向为北风,风速为3m/s,街道峡谷高宽比分别为1∶2、1∶1和2∶1时,街道中心线距地面1.5m高度细颗粒物最大质量浓度分别位于-19.3、-88.0、-19.3m(以与街道中心点的距离计,正值表示在街道中心点以东,负值表示在街道中心点以西,下同)位置,为37.5、46.4、28.4μg/m3。街道峡谷高宽比为1∶1,风向为北风,风速为3m/s,建筑物间隔分别为0、20%和40%时,街道中心线距地面1.5m高度的细颗粒物最大质量浓度分别位于148.0、-92.3、-186.7m位置,为88.1、31.6、33.7μg/m3。街道峡谷高宽比为1∶1,建筑物间隔为20%,风速为3m/s,且分别处于西风、北风和西南风时,街道中心线距地面1.5m高度的细颗粒物最大质量浓度分别位于165.3、58.0、1.5m位置,为10.6、11.2、16.0μg/m3。可见,CFD模拟近地面污染物扩散时应考虑街道峡谷结构和风向的影响。更多还原

【Abstract】 The configurations of a real street canyon and wind directioon were considered to study their influence on the dispersion of fine particulate matters.The ratio of architecture height to street width(H/W)of street canyon,the gaps between buildings(ratio of the gap between buildings to the total length of the street)and wind dircetion were discussed.Computational fluid dynamics(CFD)software was used to simulate the detailed flow,turbulence characteristics and fine particulate matters dispersion distribution in street canyon.The results indicated the maximum fine particulate matters dispersion concentration of street central line were 37.5,46.4and 28.4μg/m3 for the site of street central line of-19.3,-88.0and-19.3m(at the distance from the center of the street,the positive value indicated east of the street center,while the negative value indicated west of the street center,and the same below),respectively when the gap between buildings was 20%,wind direction was north,wind speed was 3m/s and H/W was1∶2,1∶1and 2∶1at 1.5mabove ground.The maximum fine particulate matters dispersion concentration of street central line were 88.1,31.6and 33.7μg/m3 for the site of street central line of 148.0,-92.3and-186.7m,respectively when H/W was 1∶1,wind direction was north,wind speed was 3m/s and the gaps between buildings were 0,20%,40% at 1.5 mabove ground.The maximum fine particulate matters dispersion concentration of street central line were 10.6,11.2and 16.0μg/m3 for the site of street central line of 165.3,58.0,1.5 mrespectively,when H/W was 1∶1,the gap between buildings was 20%,wind speed was 3m/s and wind directions were west,north and southwest at 1.5mabove ground.These results suggested that street canyon configuration and wind direction should be taken into account in modeling fine particulate matters dispersion.更多还原