Study on Urban Wind Patterns for Developments in Wuhan China

Abstract

This paper reports a project with the purpose to develop design guidance on urban wind fields for the Chinese city. The project assesses “super-block” developments in Wuhan China at first, then redesigns a super-block using Transit-Oriented Development (TOD) guidelines and draws wind performance comparisons. The project addresses wind Patterns for three major criteria: pedestrian comfort, air quality, and building ventilation potential. Computational Fluid Dynamics (CFD) software was used to model velocity, PMV comfort, pressure and air age patterns for summer and winter conditions. Super-blocks with isolated towers have poor urban quality on many measures, while residents drive more and use much more energy than in traditional housing. TOD guidelines solve these problems but no discussion of urban wind patterns, air pollution, pedestrian comfort, or building ventilation which have been found important during the period of Corona Virus Disease 2019 (COVID-19) in Wuhan China. Our target was to generate TOD urban form that equaled or exceeded super-block wind performance. Results were inconclusive for pedestrian comfort and other indices and modeling are needed. Other parameters depend significantly on orientation and wind direction. Therefore, sometimes TOD was better than towers and sometimes not. The general method of the project is in six parts: 1) Assess five existing super-block designs for wind performance and characterize three performance metrics; 2) Draw conclusions about performance. Select one site for redesign; 3) Using TOD guidelines, design a new neighborhood at the same density on the selected site; 4) Evaluate wind performance of the new design; 5) Select wind design strategies to improve performance and redesign the TOD neighborhood; 6) Compare wind performance of TOD neighborhood and super-block. The study indicates the value of wind field analysis for improving urban designs for multi-building sites or for development rules. We were generally able to make performance improvements for development schemes, even during the special period.