The effect of an apartment complex on flow and dispersion an urban area

In this study, the effects of an apartment complex on flow and pollutant dispersion an urban area are numerically investigated using a computational fluid dynamics (CFD) model. The CFD model are the Reynolds-averaged Navier-Stokes equations model with the renormalization group k-å turbulence model. The geographic information system (GIS) data are used as the input data of the CFD model. Numerical simulation are carried out for eight different inflow directions before and after an apartment complex is constructed in an urban area. The observation data of automatic weather system (AWS) are analyzed. The windrose analysis shows that the wind speed and direction after the construction are quite different from those before the construct. The construction of the apartment complex resulted in the decrease in the wind speed at the downwind region. It is also shown that the wind speed increased partially inside the apartment complex due to the channeling effect for the mass continuity. On the whole, the wind speed decreased at the downwind region due to the drag effect by the apartment complex. The results showed that the passive pollutant concentration increased near the downwind region of the apartment complex compared with that before the construction.