A CFD study of wind assessment in urban topology with complex wind flow. (August 2021) - Zhang, Shaowei
Highlights: An LES-based CFD model for air ventilation assessment in urban topology validated. Effects of twisted wind flow inlet on urban wind conditions evaluated. Wind-structure interactions around buildings of different heights analyzed. CFD provides comprehensive AVA potentially useful to sustainable urban plans. Abstract: This paper presents a CFD study on the air ventilation assessment (AVA) in urban topology with twisted wind profiles (TWP). At present, most AVAs were conducted through wind tunnel experiments, and conventional wind profile (CWP) with no deviation of wind direction along the heights was employed. However, in practice, the hilly terrain around cities such as Hong Kong results in twisted wind flow that wind directions vary along the heights. This paper presents an LES-based CFD model based on the best practice guidelines (BPGs). Two twisted wind profiles (TWP) were introduced, and six simulation cases were performed. The CFD predicted wind speeds were validated against wind tunnel measurements in the literature, and good agreement was achieved. With the aid of the CFD model, wind conditions over heights were investigated, and the effects of twisted wind were evaluated. The results indicated a significant influence of TWPs on the AVA's outcomes and the wind speeds' vertical distribution. In addition, with the CFD results, it is possible to investigate the wind-structure interactions in specific urban areas and provide a better understanding of the effects of buildings on the local wind conditions, which could be useful to the urban plan for sustainable cities.