Effects of outlet area on the induced flow rate of a vertical solar chimney at different heights and gaps

Solar chimney has been studied extensively by many researchers and proved to be an effective method for natural ventilation of buildings. Once properly designed, a solar chimney can help to save energy significantly and maintain thermal comfort conditions inside the building. In ideal configurations, a vertical solar chimney has been studied in the form of a straight air channel with constant flow area. In this study, we considered a solar chimney in practical applications where the outlet area of the air channel may be contracted due to other required elements, such as those for weatherproofing. The flow and heat transfer inside the air channel were simulated with a Computational Fluid Dynamics model. Effects of reducing the outlet area were examined under different heights and gaps of the air channel. The results show that reducing the outlet area significantly reduces the flow rate but increases the temperature rise through the chimney. Based on the results, one may select suitable configurations depending on the priority of the application of the chimney, i.e. higher flow rate for ventilation or higher temperature rise for heating applications.