Wind pressure coefficients for buildings with air curtains

Abstract

An air curtain is often installed at a building entrance as an air barrier to reduce infiltration and resultant energy and air quality concerns. Due to its direct contact with the ambient environment, wind could affect the air curtain’s performance significantly, whereas its interaction with the wind has not been well understood. This study carried out a series of experiments on a sub-scaled building model with an air curtain in an atmospheric boundary layer wind tunnel. A CFD model was also built to further investigate the air curtain jet interactions with the wind. The CFD model was verified and validated through Particle Image Velocimetry measurements for different air curtain and wind conditions and in terms of the function of the dimensionless air infiltration rate versus the dimensionless pressure difference across the air curtain. This study defined the wind pressure coefficient for air curtains based on their performance under wind compared to that without wind. The wind pressure coefficient was found to be constant for different air curtain supply speed, supply angle, and wind speed, but varies with wind direction, so its profile was provided as a function of wind direction. This study provides insights into air curtain performance under various wind conditions.