The Windcatcher: A Renewable-Energy-Powered Device for Natural Ventilation-The Impact of Upper Wing Walls

In recent years, there has been increased interest in natural ventilation solutions as a means to achieve sustainable and energy-efficient building design. Windcatchers, ancient Middle Eastern architectural elements, have surfaced as viable passive cooling devices in modern architecture, thereby enhancing interior air quality and reducing the reliance on mechanical ventilation systems. Integrating upper wing walls (UWWs) is hypothesized to augment a windcatcher's effectiveness by optimizing wind capture, air circulation, and thermal regulation. Therefore, this study aimed to explore the influence of incorporating a two-sided windcatcher with UWWs, with a particular emphasis on the effect of the UWW angle on ventilation performance within building spaces. To achieve this aim, a series of numerical simulations were conducted to assess the synergy between the windcatcher and the wing wall configuration with varying UWW angles and under varying wind speed conditions. As the first step of the research methodology, the CFD model was validated through a comparison between the numerical results and the experimental data. The findings showed good agreement between these methods. In the next phase, windcatchers with different UWW angles spanning the range of 0 degrees to 90 degrees were subjected to rigorous evaluation. The results revealed that the configuration with a 30 degrees angle exhibited the optimal performance concerning critical ventilation parameters encompassing the airflow rate, air change rate, and mean age of air. Finally, the selected configuration underwent an evaluation under diverse wind speed conditions, which affirmed that even under low-wind-speed conditions, the windcatcher provides ventilation levels that align with the standard requirements.