Numerical and Experimental Investigation of Aerodynamic Loads for Tall Buildings with Prismatic and Twisted Forms

Cantilevered from the ground, tall buildings reaching exceptional heights are inevitably exposed to severe lateral effects, particularly wind loads. As the structures get higher, slenderer and have larger strength-to-weight ratios, their design, both structural and architectural, is principally based on wind rather than gravity or seismic demands. Wind forces acting on this type of structures primarily depends on wind characteristics and the building form. Thus, creating distinctive forms that attract public interest and are aerodynamically efficient is an ambition of architects and engineers for decades. Recently, twisting tall buildings emerged by virtue of such a motivation. This study investigates wind effects on these complex forms through a case study research. Comparisons between wind loads on a twisted building model and those on its conventional prismatic counterpart were performed by making use of both numerical analyses and experimental measurements. The influences of facade texture, wind speed, and wind direction on separated turbulent flow around the model buildings and the aerodynamic loads acting on the buildings have been investigated. Comparisons highlighted that, wind loads around the bluff body of twisting structure is on a lower grade compared to the prismatic counterpart which is valid for both along wind and across wind directions