Abstract
<title>Abstract</title> <p>This paper investigates dynamic airflow patterns within enclosed courtyard spaces, with particular focus on traditional Cairene residential architecture in the hot-arid climate of Cairo. These buildings exemplify centuries of climate-responsive design, where passive strategies—compact layouts, thick walls, and inward-facing courtyards—were employed to optimise thermal comfort and natural ventilation. The study examines how geometric parameters, including courtyard proportions, sectional aspect ratios (SAR), and building orientations, shape airflow behaviour. By analysing solar exposure across multiple case studies, three principal airflow typologies are identified: (1) the courtyard as a cool reservoir enabling cross-ventilation driven by pressure differentials; (2) a thermal updraft exhaust system, where solar-heated surfaces generate stack-effect convection; and (3) interconnected courtyards producing gradient-induced flow through intermediate transitional spaces such as the takhtabush. Solar radiation simulations reveal that courtyard floors receive peak cumulative radiation of approximately 2.8 kW/m², generating the buoyancy forces that sustain passive ventilation cycles. The findings offer practical design guidance for climate-sensitive architectural interventions in dense urban environments, demonstrating that systematic calibration of courtyard geometry can substantially improve indoor ventilation performance without mechanical systems.</p>