Experimental and numerical analysis of a traditional four-sided windcatcher for performance evaluation and improvement

Windcatchers are traditional architectural elements that enable passive ventilation and cooling, thereby improving thermal comfort and reducing energy consumption. This study investigates the performance of a historical four-sided windcatcher in Yazd, Iran, through full-scale field measurements combined with validated CFD simulations. On-site data of air temperature and velocity were recorded, and the numerical model (steady-state RANS in ANSYS Fluent) was validated against the field measurements to ensure reliability. Following validation, airflow distribution within the connected space was analyzed, and two retrofitting strategies, namely guide vanes and one-way outlet valves, were tested to mitigate reverse flow through the leeward channels. Results showed that one-way valves were more effective, enhancing airflow velocity by up to 13.2% and 66.7% under northwest and southwest wind conditions, respectively. Overall, the findings highlight how simple design modifications can significantly enhance the performance of traditional passive ventilation systems in hot-arid climates.