A influência das configurações urbanas na qualidade do ar

Abstract

Urban morphology is a fundamental aspect of understanding the pollutant dispersion in the urban environment. Thus, the study’s main goal is to analyze, using CFD, the impact that different urban planning strategies have on the pollutant dispersion at the pedestrian level. For this, the planning strategies investigated are block typology and the urban indexes Floor Area Ratio (FAR), Surface Coverage (SC), and buildings’ height (H). To assess the interference of different urban configurations in air quality, five typologies using URANS (Unsteady Reynolds Average Navier Stokes) were simulated. The typologies are single-block, detached buildings, central courtyard, inners courtyards, and row. From the five cases, simulation pollutant concentration’s results were selected three typologies for indexes variation: single-block (lower concentration), detached buildings (greater concentration), and central courtyard (intermediary concentration), that present different porosity disposition. It was found for the basic cases that the single block typology had the lowest concentration and the detached buildings had the higher. However, with a decrease of the surface coverage (SC), this same typology had the second smallest concentration between configurations. Also, for the same FAR (5 – basic cases value), reduce the SC and, consequently, increase the building's height, resulting in less concentration than an arrangement with shorter buildings. Finally, the performance of local ventilation is not linearly related to SC but strongly depends on the arrangement of the buildings.