Unsteady RANS simulation of wind flow around a building shape obstacle

AbstractThis work aims to find the origin and connection of the surface, near-wake, and far-wake structures in the flow encompassing a high-rise building for a high Reynolds number. The origin and interconnection of the stream-wise tip vortices, with the other components of the wake, is analysed in this study for the current scenario. The Unsteady Reynolds Averaged Navier-Stokes equations (URANS) together with the realizablek- ϵ turbulence model have been used in this investigation to study the turbulent wake flow following a ground-surface-attached square shape building. A moderately big obstacle aspect ratio of 4, a Reynolds number of 12,000, and a thin evolving boundary layer thickness have been used in the flow modeling. The designed flow addresses the reversed-flows at the outlet during computation to improve the accuracy of the realizablek- ϵ model. The Reynolds stress components are retrieved using the Boussinesq approach. The wake ’s principal compositions, including span-wise-side eddies and area of high stream-wise vorticity in the uppermost portion of the wake, are illustrated by both three-dimensional (3D) representations and planner projections of the mean flow distributions. A braided vortex formation, composed of asy mmetric hairpin vortexes, is witnessed in the far-wake area. The association of the near-wake vortex structures with the far-wake and near-wall flow, which is associated with the flow strengths, is also discussed. In this investigation, few are...

Source: European Journal of Applied Physiology - November 10, 2021 Category: Physiology Source Type: research