Performance evaluation of single-sided natural ventilation for generic building using large-eddy simulations: Effect of guide vanes and adjacent obstacles

A series of computational fluid dynamics simulations was performed using large-eddy simulation (LES) of single-sided natural ventilation for a generic building model, so as to investigate the impact of guide vanes (GVs) and adjacent obstacles on the air change rate and ventilation efficiency. A building model with two openings on one sidewall aligned parallel to the direction of the approaching wind was adopted for the study, and three different GV configurations were compared: no GVs, GVs installed at both ends of the two openings, and GVs installed at the center of the two openings. In addition, the shapes and distances of adjacent obstacles opposite the openings were considered as influencing parameters. It was confirmed that the flow property within the ventilated room was affected considerably by the GV and adjacent-obstacle location combination. A natural ventilation performance evaluation method that employs the fluctuating velocity field determined from the LES was proposed and applied to the predicted flow field. The contribution of the fluctuating velocity through the openings to the ventilation performance was evaluated quantitatively by considering both the fresh-air arrival rate to the occupied zone and the effective air change rate. The importance of considering the influence of the fluctuating velocity component on the air change rate and the arrival rate was discussed.