Computational Fluid Dynamics Simulation and Experimental Study of The Airflow in a Traditional Courtyard House

Traditional courtyard houses, common in Mediterranean and Middle Eastern regions, are recognized for their ability to provide aerodynamic comfort in hot and arid climates. In the face of escalating climate change effects and health challenges amplified by the COVID-19 pandemic, there is an urgent need for sustainable architectural solutions. Courtyards, as central elements of these dwellings, play a crucial role in managing natural ventilation and creating favourable microclimates. This study specifically examines courtyard houses that have undergone significant transformations over time. Originally characterized by low courtyard heights, these houses have seen increases in elevation to accommodate growing housing needs, fundamentally altering their interaction with airflow and environmental factors. The study addresses how these architectural modifications, alongside courtyard orientation relative to prevailing winds, influence aerodynamic comfort. The primary objective of this research is to assess how the shape, height, and orientation of courtyards affect air quality and user comfort. By analyzing these parameters, the study seeks to offer architectural solutions that respond to contemporary challenges, both climatic and health-related. To achieve these objectives, the research employs a methodology combining numerical simulations using the ANSYS Fluent software, wind tunnel experiments, and a parametric analysis of morphological and climatic indicators. The case study focuses on the old town of Annaba, which has a rich heritage of courtyard houses that have been preserved since 2013.The results show that optimal courtyard orientation can improve air circulation by 25 to 45%, depending on prevailing winds and seasonal variations. Lower courtyards allow for better evacuation of hot air, while higher courtyards—introduced due to historical transformations—tend to retain more heat. These configurations, adapted to local climatic conditions, also contribute to a reduction in energy consumption by up to 30%. Furthermore, increased natural ventilation in open courtyards helps limit the transmission of airborne viruses, thereby improving indoor air quality.