Numerical investigation on the effect of avenue trees on fine particulate matters(PM2.5)dispersion
(0) he Reynolds-Averaged Navier-Stokes(RANS)model and revised generalized drift flux model were utilized to investigate the characteristics of airflow fields and PM2.5 dispersion in street canyons with different tree crown morphologies(i.e.,conical,spherical and cylindrical),leaf area densities(LADs =0.5,1.5 and 2.5 m2/m3),and street canyon aspect ratios(H/W=0.5,1.0 and 2.0).Results showed that: 1)airflow fields were reversed in the presence of trees and enhanced with increased LAD; 2)air velocity did not significantly decrease when LAD increased from l.5 t0 2.5,but significantly decreased when LAD increased from 0.5 t0 1.5; 3)tree crown morphologies,building aspect ratios and LADs interacted with each other.The comparison of PM2.5 showed that the most critical situations in H/W=0.5,1.0,and 2.0 correspond to LAD=0.5 with conical canopy; 4)the H/W=1.O and LAD=1.5 scenario was identified as the most appropriate combination for PM2.5 capture; 5)the maximum PM2.5 reduction ratio was ranked from lowest to highest in the order of conical,spherical and cylindrical canopies.At predestinated LADs and aspect ratio,Populus tomentosa with cylindrical crown morphology was the most effective at PM2.5 capture with a reduction ratio of 75%t0 85%at pedestrian height.
computational fluid dynamics (CFD) PM2.5 tree crown morphology leaf area density (LAD) urban street canyon
Bo Hong Borong Lin Hongqiao Qin
College of Landscape Architecture & Arts,Northwest A&F University,Yangling 712100,China Department of Building science,School of Architecture,Tsinghua University,Beijing 100084,China
国内会议
中国环境科学学会室内环境与健康分会第八届学术年会( IEHB 2017)
重庆
英文
1-16
2017-11-04（万方平台首次上网日期，不代表论文的发表时间）