Improving aerodynamic performance of tall buildings using Fluid based Aerodynamic Modification

Abstract A novel approach is proposed to integrate active air flow control into the assembly of building envelopes in order to affect the interaction between tall buildings and surrounding air flow. The potential benefits of the proposed approach include reduction of embodied energy contained within the building structure, improvement of the overall life-cycle of building materials, and increased access to natural daylight by shallow lease spans. To date, the trend towards light-weight and high-strength materials in tall buildings, compounded with the emerging inclination towards modular prefabrication of structural assemblies, increasing flexibility and reduced damping, and greater slenderness ratios, has increased the susceptibility of the structural performance of tall buildings to dynamic wind load effects. Currently, mitigating wind loads relies on either changing structural or geometric characteristics such as the building׳s shape or through the addition of auxiliary damping systems. Furthermore, market driven pressures on increasing the slenderness ratios of tall buildings have been at odds with the socio-economic viability of the corresponding deep lease spans that tall buildings have required at their base. The proposed Fluid-based Aerodynamic Modification (FAM) approach is fundamentally different: instead of re-shaping the solid material to improve the aerodynamic ‘shape’ of the structure, fluid-based active flow control is used to manipulate the separating boundary layer in order to improve the building׳s aerodynamic performance and thus reduce the wind excitation.