Abstract: The study of wind environments in old inner cities is of extreme urgency due to their high building density and lack of open spaces and green land. Based on computational fluid dynamics technology, this paper analyses the improvement effects of the wind environment of the old urban area of Taiping Street in Changsha. Two partial renewal methods were compared    the addition of open space and unblocking existing street patterns. The results show: (1) The wind environment on Taiping streets is harsh with the current average wind speed only 0.94m/s (initial value: 2.3m/s) which is lower than the comfortable wind speed  (1.0~5.0m/s); (2) The above two renewal methods could effectively improve the wind environment in the old inner cities and also increase the overall speed by 13% and 26%, respectively. This study expands the empirical research case for the wind environment study at a micro level, and also provides scientific evidence for the selection of the renewal methods oriented to the old inner cities.

Key words: urban renewal, CFD, partial renewal, wind environment optimization, air path

摘要： 旧城区由于建筑密度高，缺少开敞空间和绿地，风环境研究极具紧迫性。基于CFD技术对长沙市太平街旧城区风环境进行分析，通过对比增加开敞空间和疏通街巷格局两种局部更新方式对旧城区风环境的改善效果进行深入研究。研究结果显示：①太平街旧城区中现状风环境恶劣，现状平均风速仅0.94m/s（初始风速：2.3m/s）,低于舒适风速（1.0~5.0m/s）；②证明增加开敞空间和梳通街巷格局两种局部更新方式都能有效的改善旧城区的风环境，并且使其整体风速分别提高13%与26%。研究为微观层面风环境研究拓展了实证研究案例，同时也为旧城区更新方式的选择提供了科学依据。

关键词: 旧城更新, CFD, 局部更新, 风环境优化, 通风廊道