Shoeleh Shoara, Seyed Majid Mofidi Shemirani, Seyed Kamaleddin Shahriari, Zahra Sadat Saeideh Zarabadi,
Volume 35, Issue 2 (4-2025)
Abstract
The utilization of natural ventilation in urban canyons plays a substantial role in lessening energy consumption and heat island effects. Determining the appropriate street canyon form is then very influential. In this study, Ansys Fluent was used to numerically measure airflow, heat transfer, and solar radiation in five three-dimensional urban environments with aspect ratios (3, 2, 1, 2/3, 1/3). The 𝑘−𝜀 turbulence model was used for the initial modeling and large eddy simulation of the final one. Three types of materials (gray aluminum composite, gray concrete, and white stone chipping) were considered for buildings and asphalt as ground material. The results showed that increasing the building surface fraction increased the walls’ average temperature and decreased the walls’ net longwave flux for three material types. Moreover, the aspect ratio was directly related to the average wall temperature and inversely related to the net long-wave flux of walls. Furthermore, the results showed that eddy height tracked the street canyon height at different aspect ratios. Comparisons also revealed that the magnitude of the vortices generated next to the buildings is approximately the same for the three materials
