Wind-induced forces and flow field of aerodynamically modified buildings

Aerodynamically modified buildings are a new trend in building design. The outer shapes play a major role in aerodynamic characteristics of the building and may offer improved safety and habitability. Various major and minor modifications in outer shapes have been examined in the literature, and their advantages over conventional shapes (square, triangular, circular) have been reported. In the present study, an experimental investigation of wind-induced aerodynamic forces and moments for height-modified tapered and set-back buildings is carried out for several angles of incidence. Three tapered models with tapering ratios (T.R. = (bottom width − top width)/height) of 5%, 10% and 15% and three corresponding set-back models are selected for the study. A numerical simulation using the DDES (delayed detached eddy simulation) approach of turbulence modeling is used to analyze the flow field around the modified building models. The results show that, mean along-wind, RMS across-wind forces and moments are reduced considerably irrespective of wind direction and the extent of reduction increases as the tapering ratio is increased. Set-back modifications are found to be more efficient in reducing the loads compared to the taper modification.