SENSITIVITY STUDIES FOR THE EVALUATION OF URBAN WIND ENVIRONMENT WITH OPENFOAM

The development of Computational Fluid Dynamics (CFD) over the past twenty years and the substantial advantages they have compared to the rest of available tools, has made studies relevant to the evaluation of pedestrian level wind environment more practical. The purpose of this study is the sensitivity analysis of particular CFD model setup settings and their effect on pedestrian level wind speeds and on spatially averaged wind speed ratio for an existing square area of 1km2 (1,000x1,000m) plot coverage in central London and for a single prevailing western wind direction. The present study examines the following factors: (a) size of the computational domain, (b) computation grid resolution, (c) iterative convergence criteria, (d) turbulence model and (e) surface roughness properties of the terrain around the area of study. The findings of the study confirm that sensitivity analysis is essential in order the CFD model settings to be optimized, balancing the accuracy of results and the simulation time.