CFD prediction of wind loading on shielded buildings at different spacings

Abstract

Wind loads are significantly reduced due to the building shielding effect – one building covered by another from the windward side. This research studies the impact of shielding on wind loads in high - rise buildings of different heights and spacing in between them. In the literature, there are not many studies, including Eurocode, discussing the effect of shielding or spacing between buildings on wind load, which results in conservative design and cost overrun. This research uses Computational Fluid Dynamics (CFD), in particular, Reynolds Averaged Navier–Stokes Equations (RANS) with standard �ɛ sub turbulence model to solve this problem. Eight cases of high-rise buildings are considered. Two of them are of isolated buildings, which includes the CAARC building as a validation model. while the remaining ones are shielded buildings with various heights and spacings. The results show that the shielding effects result in 15% higher wind loads in the upstream building (the sheilder) in comparison to what would be experienced by an isolated building. The recovery distance from such effect, in this case, is twice the width of the building. On the contrary, there is a decrease of up to 30% in wind loads on the downstream building (the shielded). In terms of height, a similar wind flow patterns are observed if the upstream building is higher than the downstream building. However, more complex behaviour is observed when the upstream building is shorter than the downstream building. The results were validated and compared with Eurocode, which provided a conservative result. It is intended that more research in this area can assist researchers, structural engineers and professionals improving their design and assist in revising design codes to make designs safer and more economical.