Study on Sustainable Urban Block Form for Urban Ventilation—Nanjing as an Example

In recent years, the issue of carbon emission has become increasingly important due to the intensification of the urban heat island effect and atmospheric pollution. Buildings, as a primary carrier of human activities, are significant sources of carbon emission problems in cities. The aim of this paper is to address the challenge of achieving carbon neutrality and building a sustainable urban environment from the perspective of urban and building ventilation. To achieve this goal, the study takes the wind environment research in Nanjing as the base point, and collects 3D physical model data of typical urban block samples in each district. A model library of different types of urban block morphological parameters in Nanjing city is then established, and CFD wind environment simulation technology is utilized to evaluate the wind environment of typical urban block samples in Nanjing city from 1.5, 5, 10, and 20 m, and analyzes the influence of different urban block morphological parameters on the urban block ventilation potential and explores the impact of different urban block morphological parameters from the urban perspective and pedestrian traffic. The analysis reveals the impact of different urban block form parameters on the ventilation potential of the urban blocks, and explores the urban and pedestrian scales to identify the urban block forms that are conducive to ventilation, to explore the potential to achieve carbon neutrality by improving carbon absorption and reducing carbon emission. In conclusion, this study provides valuable insights into the relationship between urban block morphological parameters and ventilation potential in the context of urban sustainability. By exploring the relation of different urban block designs to optimize ventilation and achieve carbon neutrality, this study offers guidance and reference for future sustainable new city construction and old city renewal. Ultimately, by prioritizing urban block designs that promote ventilation and air quality, we can build more livable and sustainable cities.