Enhancement of the Natural Ventilation within Commercial and Traditional Wind Towers in Arid Environments

Wind tower (catcher) is an old technique used to provide natural ventilation and thermal comfort in arid regions like Iran, and the Middle East. An attempt is made to improve the performance of such techniques by investigating the effects of the windward wall of a traditional wind tower. Four aerodynamic shapes are studied: circular, triangular, U and square shape. Two- and three-dimensional numerical simulations are carried out to examine the internal and external pressure caused by wind in the region of Bechar (South-West of Algeria). The obtained results showed an increase of airflow velocity at the tower outlet connected directly to the ventilated space by 28 and 16% for the circular and triangular models, respectively, and a decrease by 22% for the U-model. The separation flow zone decreased in both circular and triangular models, in comparison with U and square models. These results can improve the efficiency of natural ventilation of traditional and commercial wind towers.