Utilizing cavity flow within double skin façade for wind energy harvesting in buildings

Efficient wind energy harvesting by utilizing small-scale wind turbines in the urban environment requires techniques to enhance the desirable flow characteristics, including velocity magnitude and uniformity, and diminish the unfavorable characteristics, including high turbulence and intermittence. This study proposed a Double-Skin Façade (DSF) system with strategic openings to harvest wind energy in the built environment. A series of wind tunnel tests and CFD simulations have been conducted to investigate the characteristics and related mechanisms of flow within the cavity of DSF integrated with a tall building model at different incident wind angles. The discrepancy between numerical and experimental results generally remains within an acceptable range of 15% which validates the capability and accuracy of the developed CFD simulations in predicting the flow characteristics. It was found that the flow becomes more uniform while the turbulence progressively decays as flow progresses through the cavity for all wind directions. Hence the regions in the middle of both the leading and trailing sides of the cavity are favorable locations for installing small-scale, building-mounted wind turbines. Overall, the DSF system with a strategic opening can effectively enhance the flow within the cavity for a wide range of incident wind angles and can be adapted for wind energy harvesting purposes.