Natural ventilation induced by solar chimneys

Natural-ventilation flow through a two-dimensional but realsized square room is investigated numerically, using a commercial Computational Fluid Dynamics (CFD) software package. The flow is induced by a solar chimney positioned on the room's roof, and it is desired to have this flow passing through the lower part of the room for ventilation purpose. The chimney in turn is in the form of a parallel channel with one plate kept at a uniform temperature that is higher than that of the ambient air (by up to 40°C), while the other plate and all of the room's walls are insulated. Eftects on ventilation flow rate and flow pattern due to a range of changing factors are invcstigated. The factors include temperature of the chimney's heated plate, length and inclination of the chimney, its location and locations of the room's other openings, and the presence of a vertical partition in the room. It is found that all these factors affect either the flow rate or flow pattern, or both. Maximum flow rate is obtained when solar chimney is in a vertical position at a roofs corner, with its heated plate on the room side. On the other hand, flow rate increases with increasing solar plate's temperature and length, as expected, but the manner of the increase varies with relative positions behYcen the chimney and room inlcts