A composite model for complex building street configuration in a large eddy simulation of local urban atmospheric environment

Abstract

The wind field and pollutant dispersion are predicted numerically in a local urban area with crowded buildings and heavy traffic. A domain decomposition method is used in the large eddy simulation, in which the urban area is decomposed into a central area, where pollution is the major concern, and a surrounding region, where the pollutant distribution is not important. The composite model is proposed for the complex building-street layout. The fine grid mesh is used to resolve the buildings in the central area while the buildings are treated as roughness elements in the surrounding region where the coarse grids are used. The proposed numerical method is applied to simulate the wind field and pollutant dispersion from vehicle exhaust in the Rua Do Campo area of Macau. The results show that the composite model is an appropriate method for predicting wind field and pollutant dispersion in the crowded building area.