Wind tunnel modeling experiments on airflow characteristics of underground metro station with sunken squares

^a School of Architecture, Harbin Institute of Technology, Harbin 150000, China
^b Key Laboratory of Cold Region Urban and Rural Human Settlement Environment Science and Technology, Ministry of Industry and Information Technology, Harbin 150000, China
^c China Railway Design Corporation, Tianjin 300308, China
^d National Engineering Laboratory for Digital Construction and Evaluation Technology of Urban Rail Transit, Tianjin 300308, China

^* Corresponding author: liujinghit0@163.com

Abstract

Building airflow characteristics can affect the indoor air environment, thereby affecting indoor air quality and building energy consumption. In recent years, the sunken square has increasingly designed and applied to underground transportation hub systems, because of their special advantages, such as improving the ventilation and lighting of the underground space, blurring the feeling of the ground and underground and improving the quality of the space. However, at present, there are few systematic and comprehensive researches on the airflow characteristics of the sunken squares to the underground metro station. In this study, the wind tunnel modeling experiment and the particle image velocity (PIV) technology are comprehensively used to study the influence of the sunken square on the airflow characteristics of the underground metro station, the influence of the sunken square on the flow field distribution and air exchange rate of underground metro station are obtained. The dimensionless average wind velocity at the large openings of the sunken square is 0.053-0.18, and the air exchange rate of the underground metro station is changed with the number and the relative positions of sunken squares. Conclusions of this research could provide useful reference to the design of airflow characteristics for underground buildings.