基于DPM模型的街谷内颗粒物扩散特性研究

通过采用离散相模型（DPM），对等高对称街谷和非等高不对称街谷在参考风速Zref=2m/s时，粒径dp=10μm的固体颗粒物在街谷内的扩散分布进行了数值研究。计算湍流模型选用重正化群两方程模型，计算结果表明在城市风场作用下会导致街谷内空气呈漩涡流动，街谷几何形状变化影响街谷内污染物浓度分布，且在深街谷（B/H＝0.5）和上游建筑高于下游建筑的非对称街谷（H1/H2=2）中街谷内空气颗粒无量纲浓度远高于同类型其它几何尺寸街谷。

Study of aerosol dispersion in urban street canyon based on DPM model

Based on discrete phase model(DPM), a simulation was carried out to study the aerosols with diameter of 10 microns dispersed in different kinds of geometrical street canyons when referenced wind velocity Zref=2m/s. In the simulation, renormalization group two equations model was used as turbulence model. The numerical results indicated that due to urban wind field the air in the street canyon present vortex’s flow, street canyon aspect dimension ratio have crucial effect on the aerosol concentration distributing. Moreover the nondimensional concentration of the street canyon with the aspect ration of B/H=0.5 and H1/H2=2 is more dense than others.