Temporal and spatial diffusion simulation of traffic exhaust in urban street canyons
For signal control section,based on the κ-ε model and species transport equations,we have studied the temporal and spatial diffusion process of vehicle exhaust CO under dynamic traffic flow in urban street canyons,and made a comparison of stationary simulation results with and without signal.The results show that:(1) the CO concentration features spatial and temporal heterogeneity owing to the traffic signal control system and flow field in urban street canyons ; (2) the CO concentration of leeward side is always much higher than that of windward side,and both of their peak values are in the center of street canyon; (3) in the signal period,the CO concentration in the sidewalk is much higher than that of any other areas in the canyon,it would be 24.15 mg/m3 which exceeds 141.50％ of national secondary standard; (4) influenced by signal control,the CO concentration in signal control sections is much higher than that in non-signal control sections,especially,the CO concentration in the leeward side of sidewalk is 3.5 times higher than that in non-signal control sections.
street canyonspollution concentrationnumerical simulationtraffic exhaust
国家科技期刊平台
NSTL
万方数据
维普
