Detailed modelling of the wind comfort in a city avenue at the pedestrian level

CESAM & Department of Environment and Planning, University of Aveiro, 3810-193 Aveiro, Portugal

Abstract

The interrelations between microclimatic conditions and urban morphology determine the comfort of pedestrians in a city. This work evaluates the wind comfort, based on international criteria, in a 1.1 km long avenue. For this purpose the CFD model Fluent was applied. 3D virtual simulation domain was constructed from GIS file of the area using a CAD tool. Results show a very complex wind flow in this urban canyon, as a result of its architectural characteristics and relative wind direction. The orientation of the canyon relative to the prevailing wind direction, its configuration (namely its aspect ratio), the presence of tall buildings in the edge of the avenue, and the absence of trees, induce a swirling flow that increases in speed along its length, as a typical channelling effect. As a consequence, comfort conditions are very distinct in the different sections of the avenue. Based on this work, the areas that do not meet the comfort criterion were identified, supporting the implementation of adequate mitigation measures (as natural or artificial windbreakers).