Aerodynamic optimization for corner modification of octagonal-shape tall buildings using computational approach

Abstract

Tall buildings are particularly susceptible to wind loads, which usually govern the design of lateral load-resisting systems. Therefore, wind loads must be adequately evaluated in the design of tall buildings. Aerodynamic modifications are highly effective tools for reducing wind loads. This paper investigates the effectiveness of corner modification optimization applied on an octagonal-plan-shaped model using computational fluid dynamic (CFD) simulation computational fluid dynamics associated with finite element analysis to alleviate wind-induced loads. Corner aerodynamic modifications such as chamfered, recessed, rounded, and fins are investigated. The corner modification was limited to a cutting radius of 6 m (12% of the building width) with a 0.5 m increment. The main considerations for this optimization procedure are top deflection, inter-story drifts, and the optimal number of additional floors. All corner modifications improve the building's performance, except fins corners resulting in adverse effects. In addition, 47 simulation examples from the case study are evaluated, presented, and discussed. With one additional floor, the optimum shape was able to reduce overall wind loads by 31.67%, resulting in a reduction in the structural response of 24.89% and 24.18% in maximum top deflection and inter-story drift, respectively.