The Impact of Traffic Conditions on PM2.5 Dispersion near Viaduct in a Street Canyon
HUANG Yuting
LIU Yonghong
XU Weijia
LI Li
Abstract：Dispersion of PM2.5 and the flow field in a street canyon with viaduct were simulated by k-ε model and discrete phase model based on Lagrangian method in three dimension to explore the effect of traffic conditions on PM2.5 pollution distribution. Traffic emissions and vehicle induced turbulence were considered to explore the influence of traffic conditions (free-flow and congested) on the distribution of PM2.5 in different wind directions. The simulation results show that the flow field was affected by wind condition and the structure of viaduct. Particle dispersion conditions changed with vehicle induced turbulence in different traffic conditions. Vehicles induced more turbulence in the traffic flow zone and increased the turbulent kinetic energy (TKE) nearby in free flow condition. Particle emission was higher and turbulence is weaker in congested traffic condition, which caused the concentration 5.60％～47.13％ higher in the street canyon. Particle dispersion and concentration distribution were affected by the combined effect of the changes in emission and turbulence from traffic.
Keywords：traffic conditionPM2.5viaductdispersion modelling
Publication Date：2018-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：8( 71-78 )