An experimental investigation of a solar chimney model with uniform wall heat flux

Experiments were carried out using an experimental solar chimney model with uniform heat flux on one chimney wall with a variable chimney gap-to-height ratio between 1:15 and 2:5 and different heat flux and inclination angles. Results showed that a maximum airflow rate was achieved at an inclination angle around 45° for a 200 mm gap and 1.5 m high chimney, and the airflow rate is about 45% higher than that for a vertical chimney at otherwise identical conditions. It was found that the prediction method available in the literature can substantially overpredict the airflow rate for the chimney geometry investigated in this work, especially for vertical chimneys with large gaps. The main reason for the overprediction of airflow rate was shown due to the underestimation of the pressure losses at the chimney outlet by using loss coefficients obtained for normal forced flows.