Mesh-adaptive LES for wind load estimation of a high-rise building in a city

This paper discusses the applicability of large eddy simulation (LES) to the wind-resistant design of buildings in cities. In order to accurately predict wind pressures and forces on actual buildings with complicated shapes, we partially introduce the unstructured grid system, which is formulated on the open-source CFD code. Applying the LES method for modeling the urban flow, where a specified high-rise building focuses on safety under wind loading, the combined model is employed to investigate aerodynamic characteristics. This model uses overset grids, consisting of the Cartesian grid and the unstructured-grids. According to previous studies, the Cartesian grid method can accurately generate the turbulent structures in the urban canopy, whereas the unstructured grid method can reproduce detailed patterns of the near-wake flows around a specified building inside a densely built-up area. In this study, we have applied the combined model consisting of the Cartesian grid and unstructured grid for wind load estimation of a high-rise building in a city. Particularly, at inclined wind direction to the main streets, there is a presumption of different effects of wind impact at each vertical level of a high-rise building along the street. Accordingly, relatively a large torsional force tends to be present. On the basis of the results obtained, their accuracy is checked in comparison with the previous data by wind tunnel experiment, and wind pressure distributions on the surfaces as well as wind force coefficients of a highrise building are estimated and discussed in view of structural safety. (C) 2015 Elsevier Ltd. All rights reserved.