Assessing Pedestrian Comfort in Dense Urban Areas Using CFD Simulations: A Study on Wind Angle and Building Height Variations

This study investigates pedestrian comfort in a dense urban environment by evaluating the Mean Velocity Ratio (MVR) and Overall Mean Velocity Ratio (OMVR) criteria. It examines how neighboring building heights and wind incidence angles affect pedestrian-level wind conditions within a nine-building arrangement. Using Computational Fluid Dynamics (CFD) with the Reynolds-Averaged Navier-Stokes (RANS) k-ε model, validated against experimental data, this study analyzes scenarios where surrounding building heights vary from 0L to 6L and wind angles from 0° to 45°. The results demonstrate that wind angles perpendicular to the urban canyons (0° case) induce strong channeling effects, leading to MVR peaks as high as 3.42 and creating hazardous conditions. Conversely, an oblique 45° wind angle promotes more uniform airflow, significantly improving comfort. Increasing the height of neighboring buildings generally elevates the mean MVR due to enhanced channeling. However, even an isolated building (0L case) can generate high localized velocities due to flow separation. The findings underscore that both building configuration and wind direction are critical factors, and CFD serves as an essential tool for urban planners to mitigate adverse wind conditions and ensure pedestrian comfort.