Influence of air infiltration on airflow in a ventilated isothermal two-zone enclosure

Abstract Influences of air infiltration on the airflow and contaminant distribution in a ventilated isothermal two-zone enclosure are investigated by numerical simulation. The direction of infiltration airflow is considered to be in the opposite direction of the room ventilation air. The enclusure is divided into two zones, zone A and zone B, by a partition with a door opening. The ventilation air flows into zone A (namely ventilition zone) through a rectangular supply opening near the floor on the end-wall of the zone and leaves the enclosure through a ceiling-mounted exhaust opening in zone B. The infiltration air flows uniformly into zone B (namely infiltration zone) through the other end-wall, and leaves through the exhaust. Three different values of air infiltration rate are considered. In the analysis of the combined influence of door-opening position and infiltration on the air movement, the door opening is placed at three positions, namely, y D / W = 0.167, 0.5 and 0.833 respectively. The airflow is considered to be three-dimensional and fully turbulent. The predicted results indicate that a local exhaust will effectively limit the transportation of the contaminant from the infiltration zone into the ventilation zone, and the effect of infiltration on its downstream zone could be negligibly small, if the door opening and the exhaust are properly placed.