Towards LES as a design tool: Wind loads assessment on a high-rise building

Abstract

The accurate evaluation of wind loads on high-rise buildings represents a key point in their design process. Traditionally, atmospheric boundary layer wind tunnel tests, conceived in order to be representative of the wind conditions expected on site, are used for this purpose. Recently, owing to the increase in computational power, Computational Fluid Dynamics (CFD) techniques have gained interest as a complementary tool to wind tunnel testing. Unfortunately, wind flow around bluff bodies is often very complex and substantial research efforts are still needed in order to assess the accuracy and reliability of CFD results. In this paper, Large Eddy Simulations (LES) are performed aimed at evaluating the wind loads on an isolated high-rise building. In order to assess the capabilities of LES for adoption as a design tool, the results are analysed in terms of both pressure distributions and internal forces on the structural elements. It is found that the accuracy of LES in reproducing the fluctuating pressure field is not necessarily maintained when internal forces are taken into account. Nevertheless, the design values predicted by LES can be still considered satisfactory, in particular when maximum and minimum values over different angles of attack are considered.