EXPERIMENTAL AND NUMERICAL INVESTIGATION OF THE AERODYNAMIC PERFORMANCE OF Y-SHAPED TALL BUILDINGS WITH CHAMFERED CORNERS MODIFICATION

Abstract

Modern urbanization has witnessed the emergence of new buildings, particularly tall buildings with unconventional forms like Y-plan buildings This study tackles the significant problem of wind loading on tall, non-symmetrical structures such as the Y shaped structure commonly found in urban design of which there are increasing in numbers. The main issue investigated is how high wind stresses can create structural instability and structural problems related to strong wind suction (negative forces) affecting the building's facade and structure. To overcome this, the aerodynamic performance of the SY model is considered and the effectiveness of a Chamfered Y shaped (CY) model as a design modification is evaluated. The central challenge is to define the effects of geometric refinement in case chamfered corners, the control of the air flow and the reduction of the negative influence of wind loading on high-rise buildings. Methodology applied is a hybrid method which is a combination of computational fluid dynamic (CFD) simulation and physical wind tunnel test to get comprehensive and validated results. ANSYS CFX software was used to simulate steady-state wind flow around the models at wind incidence angles of 0°, 30°, 60°, 90°, 120°, 150° and 180°. These numerical results were then carefully compared with the experimental results from a boundary layer wind tunnel. This research clearly shows that the chamfered design outperforms the other designs in terms of aerodynamics. As can be seen in the data, the CY model always has uniform pressure distribution and significantly lower peak suction values than the sharp-edged SY model. The chamfers effectively delay flow separation and smoothen the flow around the structure, as revealed by streamline analysis. The chamfered shape mitigates wind-induced stresses that a building has to endure, and shows how small changes in geometry can make a significant difference in aerodynamic efficiency. The decrease in wind induced stress increase the life span of structure and makes it serviceable. Also, ground level wind reduction in dense urban areas is a common problem, and mitigation of wind vortices will help to create a more pleasant and safe pedestrian environment.