三维街道峡谷机动车尾气时空扩散模拟研究  

Temporal and spatial diffusion simulation of traffic exhaust in urban street canyons

作　　者：麦戈[1] 徐伟嘉[2,3] 幸鸿[3] 何芳芳[2] 刘永红[3] 

机构地区：[1]仲恺农业工程学院城市建设学院,广州510225 [2]中山大学先进技术研究院,广州510275 [3]中山大学工学院,广州510275

出　　处：《环境工程学报》2015年第2期867-872,共6页Chinese Journal of Environmental Engineering

基　　金：广东省自然科学基金资助项目(S2012010008943);佛山市科技发展专项资金项目(2012AA100741)

摘　　要：针对信号控制路段,采用非稳态k-ε湍流模型、组分输运方程进行非定常三维街道峡谷数值模拟,研究了三维街道峡谷内动态交通流下机动车污染物CO的时空扩散过程,并对比了含信号、不含信号的定常模拟结果。结果表明,(1)受信号控制及峡谷内流场影响,峡谷内污染物浓度呈现显著的时空不均匀性;(2)各路段背风面浓度值要大于迎风面,且背风面和迎风面浓度峰值均位于峡谷中部的人行横道区;(3)信号周期内人行横道区污染物浓度始终远高于峡谷内其他区域。在距离背风面建筑1 m的人行横道处污染物浓度可达24.15 mg/m3,超过国家空气质量二级标准141.50%;(4)受信号控制影响,含信号控制街道峡谷污染物浓度高于不含信号控制路段,人行横道背风面污染物浓度是不含信号控制人行横道的3.5倍。For signal control section,based on the k-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.

关 键 词：街道峡谷 污染物浓度 数值模拟 机动车尾气 

分 类 号：X734.2[环境科学与工程—环境工程]