摘要
应用标准 k-ε模型及其修正模型预测了城市街道峡谷的大气流动和汽车排放污染物浓度场分布 ,并与风洞实验结果进行对比 ,计算结果与实验结果总体趋势上非常一致 .在街道峡谷的外围流场 ,修正模型明显优于标准模型 ,但在街道峡谷内部的浓度场分布 ,不同模型在建筑物顶部和地面附近存在明显差别 .在地面附近 ,标准模型与实验结果吻合更好 ,这反映了由于建筑物或建筑群的存在改变了流动结构 ,使流动不能充分发展 ,因而应用不同模型得到的规律性认识与充分发展的流动有所不同 .考虑到人的活动主要集中在地面附近 ,标准 k-
The k ε model and the modified k ε models, such as the RNG and the Chen Kim models were used to predict the airflow and vehicle emission pollutant dispersion in an urban street canyon. The predicted results were compared with the wind tunnel experimental data. A general agreement between the numerical and experimental results was obtained. The results of the modified models are better than those of the standard model for the periphery of the canyon. But obvious discrepancies are also observed with the different models inside the street canyon, especially at the top and the ground level of the canyon. The standard model is in better agreement with the experimental data near the base of the canyon. That the knowledge of the flow characteristics is different from the developed flow may reveal that the flow structure is changed due to the hinder of a building or building groups. The concentration distributon close to the ground level of a street canyon with a heavy concentration of the population is of great interest to us. This suggests that the standard k ε model is still preferred for modelling street canyon airflow and pollutant dispersion.
出处
《上海交通大学学报》
EI
CAS
CSCD
北大核心
2002年第10期1496-1499,共4页
Journal of Shanghai Jiaotong University
基金
通用 -中国发展研究基金资助项目 (4 0 12 2 2 0 1)
