Study of influence of shading louvers on wind characteristics around buildings under different wind directions

Abstract

In this paper, the wind characteristics on building with single-sided louvers under different wind directions were studied by using computational fluid dynamics (CFD) method. The RNG k-ε model was employed to establish the different outdoor airflow fields under different rotation angles θ of louvers. To investigate the wind pressure on facades, wind pressure coefficient C _P was introduced and average surface difference ΔC _P was applied to evaluate wind-induced cross ventilation between the shaded and the opposite building surfaces. Results show that airflow pattern around the studied building is highly dependent on the building envelope under shading conditions due to obstruction and diversion of louvers. In general, the larger rotation angle of louvers contributed to more differences in average surface C _P under both normal and parallel wind directions. Shading louvers lead to an increase in ΔC _P for parallel approach flow and a decrease in ΔC _P for perpendicular approach flow. In simulations of this study, it could be seen that ΔC _P decreases 0.01 (1.6%) for θ = 0° and 0.15 (18.0%) for θ = 60° under normal wind direction, while ΔC _P increases 0.05 (436.1%) for θ = 0° and 0.15 (1393.5%) for θ = 60° under parallel wind direction. The results elucidates that a larger rotation angle can affect wind-induced cross ventilation more strongly. What’s more, the locations of minimum and maximum C _P on some facades moved obviously after shading and turning up rotation angle. This study indicates that the influence of complex building envelopes like shading louvers, should be considered in ventilation design.