Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
A COMPARATIVE STUDY OF RANS TURBULENCE MODELS AND INFLUENCE OF WIND DIRECTION IN A BUILDING ARRAY
Submission Author:
Gabriel Gusmão Almeida , ES
Co-Authors:
Gabriel Gusmão Almeida, Fernanda Capucho Cezana
Presenter: Gabriel Gusmão Almeida
doi://10.26678/ABCM.COBEM2021.COB2021-1526
Abstract
The intense urbanization that we experience promotes the construction of many building inside urban areas, which affects the local airflow, contributes to the pollutant accumulation, compromises the air quality and many times lead to a decrease in population’s health. Therefore, it becomes necessary to study about the atmospheric flow around a group of obstacles, aiming to gain knowledge regarding the characteristics present in urban flows. This line of research shows relevance because the urban areas flow patterns, which is mostly turbulent and complex, when modelled in a reliable and low computational way could facilitate the analysis of some parameter’s influence such as wind direction, building’s height and its configuration, furthermore, these parameters directly affects the pollutant dispersion. Such knowledge would be useful to predict the emergence of regions with high concentrations of pollutant and considering the fact that these kind of regions bring health risks to the population nearby, it makes possible the application of prevention measurements to reduce such risks. The present study used Computational Fluid Dynamics (CFD) through Ansys Fluent 16.0 software to evaluate the performance of four Reynolds Averaged Navier Stokes (RANS) turbulence models in describing the flow aforementioned, which are the Standard k-ε, SST k-ω, the Reynolds Stress Linear Pressure-Strain and the Stress-Omega Models. The studied case was an idealized urban canopy with twenty-four unequally spaced buildings with rectangular cross sections and constant height. The data obtained through numerical simulations was compared and validated with experimental data available in the specialized scientific literature. The Reynolds Stress Model (RSM) Stress-Omega was the one that performed better in modelling the flow, mainly near the floor, despite that, the Standard k-ε model also performed well given its low computational cost compared to RSM models. Wind direction influence was also analyzed and discussed using the RSM Stress-Omega. It was found that the flow pattern is very affected by the wind direction, with the formation of eddies and low-velocity regions.
Keywords
Turbulence modelling, Group of obstacles, Urban Area, Wind direction
