LES application to wind pressure prediction for tall building on complex terrain

Abstract

This study conducted numerical simulations based on the large eddy simulation (LES) model, which employs an unstructured grid system and exhibits high performance in parallel computing, to investigate the effects of a circumferential environment, such as real terrain and surrounding buildings, on the unsteady pressure fields acting on a tall building with a rectangular section. There are three numerical examples using an irregularly shaped high-rise building (aspect ratios: height/length = 7/4 and length/width = 24/11), the same building on a complex terrain, and the same building with surrounding buildings on a complex terrain. To elucidate the statistical pressure characteristics, we focused on the mean, fluctuating, and peak values on the surfaces of the target building. The pressures for the present models were validated through a comparison with experimental data obtained under the same conditions. Subsequently, the velocity and pressure fields directly influenced by the complex local terrain and surrounding buildings were studied. A concave terrain located on the leeward side of the target building could cause a large negative pressure on the side surfaces as a result of access to the deformed separating flow. In addition, the surrounding buildings led to the movement of the stagnation point to a higher location on the windward surface and intensification of the conical vortex attached to the side surface.