Case Study on the Pedestrian Wind Environment of Commercial Streets in Beijing and Tokyo Based on CFD Simulation

Abstract

Due to modern lifestyles, commercial streets have become an indispensable place in urban life. Pedestrian wind environment is one of the primary concerns in commercial street design since it has direct influences on urban heat island effect, indoor and outdoor thermal comfort, outdoor air pollution and indoor air quality. To investigate pedestrian wind environment of a commercial street, a case study was performed on Beijing Wangfujing Commercial District in China and Tokyo Sensoji Temple District in Japan separately. First, the original models of these two commercial streets were established based on real streetscapes and the surrounding buildings. The velocity filed under typical summer climatic conditions was then output to assess the wind environment of each street. The results show that pedestrian wind environment under the current design is not comfortable for Beijing street and Tokyo street. To improve this situation, further work was conducted on optimization of current street design, specifically on the determination of a suitable aspect ratio H/W (W is the width of the street and H is the height of the street buildings). In this step, simplified models derived from original models of each street were used for simulation. According to present simulation results, the determined aspect ratio H/W is about 0.80 and 0.30 for Beijing street and Tokyo street, respectively. It should be noticed that this ratio could differ on the height of the street buildings as well as on the climatic condition of the street locations.