Abstract:
Wind tunnel experiments are conducted on a single zone building with a two-sided windcatcher and a window. Mean and fluctuating surface pressures are measured to investigate the effect of the turbulent onset flows on building ventilation. Additionally, an analytical model is developed to estimate the unsteady ventilation flow rates through the building. The results are presented at different wind incidence angles and relative to the room window condition (opened versus closed window), showing the performance behaviour of the windcatcher. It is found that the mean flows can indicate generalised ventilation aspects for designing considerations. Meanwhile, the unsteady analyses should be considered when the building openings face indirect wind streams and when both a windcatcher opening and the (opened) window are presented as windward openings. Furthermore, the room window is essential when implementing windcatcher ventilation systems, as it defines their performance and dominates the interior flow behaviour.