A Combined Experimental and Numerical Study of Airflow in a Solar Chimney-Ventilated Space

This study investigates the thermal performance of solar chimneys through a combined numerical and experimental approach, aiming to enhance natural ventilation in enclosed spaces. A high-fidelity Computational Fluid Dynamics (CFD) model was developed and rigorously validated against experimental data, demonstrating strong agreement with an average deviation of 3.7%. This validated model served as a robust tool for assessing the impact of key geometric and operational parameters on overall ventilation performance. The study focused on the influence of chimney inclination angle and vertical height, which were systematically varied to determine their effects on mass flow rate and airflow characteristics. The results reveal that both solar radiation intensity and the chimney's inclination angle are critical factors influencing thermally driven ventilation. Specifically, the most favorable airflow rates were recorded when the inclination angle ranged between 60° and 75°, indicating this interval as optimal for maximizing chimney performance. Additionally, increasing chimney height was shown to enhance airflow by enlarging the solar absorbing surface area and amplifying the stack effect, thereby promoting more efficient vertical air displacement. The study emphasizes the importance of achieving an optimal balance between the temperature differential across the chimney and the aerodynamic resistance within the flow domain. This balance is essential for maximizing the mass flow rate without introducing excessive pressure drops that could hinder performance. The findings provide valuable insights for the design and optimization of solar chimney systems aimed at improving energy efficient natural ventilation in buildings