A NUMERICAL STUDY ON THE EFFECTS OF SKYSCRAPERS ON FLOW AND DISPERSION IN A METROPOLIS

The aim of this study is to investigate the effects of skyscrapers on the flow and dispersion characteristics in metropolitan area. For this, a three-dimensional computational fluid dynamics (CFD) model with the renormalization group (RNG) k-ε turbulence model is employed. To examine the skyscrapers effects, two building configurations (with/without skyscrapers) are considered. For each configuration, three cases with different ambient wind directions (westerly, southwesterly and southerly) are examined. In the absence of the skyscrapers, monotonous wind patterns are shown. The results show that the skyscrapers affected the variation of flow field nearby significantly. Within the skyscrapers, wind speed increased compared with that in the case without the skyscrapers. The increase in wind speed, channeling effect, is caused to satisfy the mass continuity. On the other hand, at the downwind region, wind speed decreased compared with that in the case without the skyscrapers due to the drag effect of the skyscrapers. The results of the dispersion model assuming the line sources with the constant emission rate showed that increased at the downwind region after construction of the skyscrapers