城市街道峡谷气流和污染物分布的数值模拟

应用计算流体力学(CFD)软件中的FLUENT软件模拟了典型城市街道峡谷中的气流和污染物分布状况.建立的模型包括不同形状的建筑物所构成的街道峡谷和存在高架桥的街道峡谷.研究结果表明:①不同形状的建筑物改变了街道峡谷内的风和湍流分布,从而对街道峡谷内污染物的分布产生很大的影响,在几何比例相同的街道峡谷里,建筑物外形越趋向于流线型,街道峡谷里污染物的地面浓度越小;②高架桥对街道峡谷内污染物浓度的影响取决于高架桥相对于街道峡谷的高度和宽度,高度越高、宽度越窄的高架桥其地面污染物的浓度越低;③ FLUENT软件对街道峡谷大气环境的模拟结果基本合理,可用于研究城市大气环境问题. 

The Numerical Simulation of Air Flow and Pollutant Distribution in Street Canyons

The air flow and pollutant distribution in typical street canyons were simulated by applying FLUENT model of CFD software.The model established includes street canyons constructed by different shapes of buildings and street canyons with viaducts.Results show that: ① different shapes of buildings change the distribution of the wind and turbulence,and thereby the pollutant concentration distribution in street canyons is significantly affected;with the same geometric proportion,the ground concentration of pollutant in street canyons is higher when the building shape is more streamlining;② the influence of viaducts lies on the height and width of the viaducts relative of street canyons;if viaduct is higher and narrower,the ground concentration of pollutants is lower;③ the simulated result of FLUENT is reasonable,and the prospect of applying FLUENT to study atmospheric environment is very well.