This thesis is to investigate the influence of upstream turbulence profile to the downstream wind velocity profiles and turbulent kinetic energy profiles within the street canyon in an urban environment. In this study, Computational Fluid Dynamics (CFD) technique is employed to model the wind environment. It is found that the turbulence would be internally generated by the upwind building obstacles, and the downwind velocity profiles and turbulent profiles would not significantly be dependent on different input turbulent profiles as the flow advanced from the upstream region to the downstream region. Wind tunnel results are compared with CFD result of the control case for validation. Different turbulent profiles with a same velocity profile are input as upstream boundary condition is in...[ Read more ]

This thesis is to investigate the influence of upstream turbulence profile to the downstream wind velocity profiles and turbulent kinetic energy profiles within the street canyon in an urban environment. In this study, Computational Fluid Dynamics (CFD) technique is employed to model the wind environment. It is found that the turbulence would be internally generated by the upwind building obstacles, and the downwind velocity profiles and turbulent profiles would not significantly be dependent on different input turbulent profiles as the flow advanced from the upstream region to the downstream region. Wind tunnel results are compared with CFD result of the control case for validation. Different turbulent profiles with a same velocity profile are input as upstream boundary condition is investigated with seven different geometry settings. The Realizable k−ε model and the DES turbulence model which is a hybrid LES/RANS model are utilized in the study. Turbulent kinetic energy and wind speed ratio are obtained at different locations of the computational domain and used as an indicator for comparison and investigation.