A Computational Fluid Dynamics (CFD) study on the effectiveness of trees on pedestrian level wind environment in urban areas

The present study aims to investigate the role of vegetation in regulating pedestrian-level wind on Imam Street. Imam Street is one of the main streets of Tabriz city, and the wind speed at pedestrian level has made pedestrians feel uncomfortable, especially in the cold season. The method of the present study is descriptive-analytical research, in which numerical simulation was carried out to simulate wind flow for the current state and different proposed states using Dlubal RWIND 2.02 software. To this end, the effects of height, distance, and arrangement of vegetation (along with tree benches) (as the independent variables) on pedestrian-level wind speed (as the dependent variable) were investigated, and the relationships between the variables were examined using Spearman's correlation.
The findings indicated that planting trees with a height of 6 meters, spaced at a distance of 3 meters according to density pattern 1, can enhance wind comfort on Imam Street by reducing the wind speed at the pedestrian level by 60%. The results showed that the use of vegetation compatible with the climate, at a given distance and according to a proper pattern, can significantly reduce wind speed. The surrounding tree benches direct the airflow towards the street and moderate the wind speed at the pedestrian level.