Application of Wind Fairings for Building Aerodynamic Optimization

For super-tall buildings of 300 m or taller, across-wind response is one of the major design challenges which the building designers must overcome. Compared with along-wind response, across-wind response is more sensitive to building’s outer geometry. A corner shape modification within 10% of building width may result in a reduction of 25% in overturning moments. Therefore, aerodynamic optimizations have drawn a great attention in building design community. A feasibility study on the application of wind fairings for building aerodynamic optimizations is presented in this paper. Based on principles of wind-adaptable design (WAD), wind fairings can be used as operable flow control devices to optimize building’s aerodynamic properties during severe wind storms. With this approach, the common design conflicts between architectural concepts and aerodynamic requirements can be avoided, and wind effects on buildings can therefore be dealt with more smoothly and efficiently during design. This paper lays out the criteria for wind fairing design that meet the requirements for WAD. Two types of fairing, Scheme A and Scheme B, are studied. Detailed parameter studies using high-frequency force-balance (HFFB) technique are introduced, aiming at optimizing size of the wind fairings to further enhance their effectiveness. It was found that for Scheme A fairings, the optimal configuration has a relative width of about 1/10, a relative height of 1/5 or more, and a fairing angle of about 45 degrees. For Scheme B fairings, the optimal configuration has a relative width of about 1/10 and a relative gap of about 1/10. Although further optimization is still possible, the current study has validated that a reduction of about 20% on design wind loads is reachable with properly designed wind fairings.