Ventilation and pollutant dispersion in a group of courtyard buildings with a diagonal wind

DICAAR - Dipartimento di Ingegneria Civile, Ambientale e Architettura, University of Cagliari, via Marengo 2, 09123 Cagliari, Italy

^* Corresponding author: ferraris@unica.it

Published online: 4 July 2024

Abstract

The urban built environment strongly modifies the wind flows and, consequently, can cause heat and pollutant accumulation. The former contributes to generate the Urban Heat Island phenomenon, the latter to the increase in health issues recorded in the cities. Both of them can be mitigated through the proper implementation of the Urban Microclimate Design, which is a design and planning strategy employing the shape and layout of buildings to optimize comfort, air quality and energy efficiency of the built environment and, consequently, contributing to the generation of mitigative cities. In this paper, we present a parametric study, via numerical simulations employing the ENVI-met® three-dimensional microclimate model, of the ventilation and of the dispersion of a pollutant inside and outside a group of courtyard buildings hit by a diagonal wind. All the variables are kept constant, except the length of the internal courtyard, which is the variable parameter. The results suggest that the shape of these buildings biases the air flows and pollutant behaviour, so pointing out that it can be efficiently used to improve the air quality and the outdoor human comfort in the modern cities.