Integrating multiple models into computational fluid dynamics for fine three-dimensional simulation of urban waterfront wind environments: A case study in Hangzhou, China

A comfortable wind environment in urban waterfront area (UWA) is critical to improving the quality of life of surrounding residents and environment sustainability. In this study, the porous media model was combined with the water-air interface exchange model to conduct high-precision three-dimensional (3D) simulation of the ventilation environment at an urban waterfront. The results of this study indicate that the accuracy of the proposed model is as high as 95%. This model can be used to efficiently simulate urban ventilation and pedestrian wind environment comfort at different heights (1.5, 10, and 30 m) in a certain high-density 3D UWA. The order of ventilation potential of different types of urban areas is road space, green space, and river space. In summer, the pedestrian wind environment around the Gongshu section of the Beijing-Hangzhou Grand Canal was discovered to have low comfort at a height of 1.5 m. In winter, the wind comfort of the UWA on both sides of the canal is greatly affected by the direction of incoming wind, showing satisfactory ventilation performance when reaching heights of 10 and 30m. Accurate and efficient 3D simulation of urban ventilation is very helpful for adaptive planning and design of urban wind environment.