Effect of lift-up design on pedestrian level wind comfort around isolated building under different wind directions

The pedestrian level wind environment is seriously worsen by moderated air flow in the built-up cities like Hong Kong. The lift-up design is therefore adopted in the building constructions to improve the weak wind condition. In order to evaluate the influence of lift-up design on the pedestrian level wind comfort, the wind flow around isolated buildings with and without Lift-up design are simulated respectively via CFD approach. The turbulence model and numerical method are firstly validated by comparing the simulated wind flow data with a wind tunnel test. Then the validated model is used to simulate the wind flows around the isolated buildings. Results show that the lift-up design can improve the wind comfort at pedestrian level and its effects are highly rely on the approaching wind direction. Specifically, the wind comfort is better under the oblique wind direction than the other wind directions.