Numerical simulation of pedestrian level wind conditions: effect of building shape and orientation

Abstract

Pedestrian level wind comfort, natural ventilation and pollutant dispersion are strongly influenced by building shape and orientation. In the recent years, the trend of building shape is not restricted to basic square and rectangular cross-section, and various unconventional shapes are also considered. Considering this fact, the present study is focused on the investigation of different building shape with major and minor modifications on the pedestrian level wind environment and aims to evaluate the effect of different building shapes on the extent of different wind conditions surrounding the building systematically. An investigation was performed using a computational fluid dynamics (CFD) approach based on realizable $$k - \varepsilon$$ model and the standard $$k - \varepsilon$$ turbulence model with revised closure coefficients for different orientation ( $$\theta = 0^\circ$$ , $$22.5^\circ$$ and $$45^\circ$$ ) and shape of buildings. Further, wind tunnel experiment was conducted to validate the CFD results. The results of CFD simulations obtained using realizable $$k - \varepsilon$$ model fairly match with experimental values for high wind speed conditions, whereas the standard $$k - \varepsilon$$ with LK modification and revised closure coefficients performs better for the low wind speed regions. It was observed that the wind conditions at the pedestrian level are influenced mostly by corner modification and projected width at 1/3rd height of the building from the ground.