Enhancing Underground Thermal Environments in Cairo: The Role of Subway Entrance Geometry in Optimizing Natural Ventilation

In rapidly urbanizing regions, enhancing passenger comfort in subway systems through sustainable methods is a critical challenge. This study introduces an innovative exploration of the impact of subway entrance geometry on natural ventilation and its subsequent effects on the thermal environment within Cairo’s subway system. The primary objective is to identify optimal entrance configurations that maximize natural airflow, thereby improving passenger comfort and reducing energy consumption. Focusing on the newly constructed segments of the Cairo subway, the research employs a mixed-methods approach that integrates computational fluid dynamics (CFD) simulations with a questionnaire survey to evaluate interactions between various entrance designs and urban wind flow patterns. This dual approach allows for a comprehensive assessment of how different geometrical configurations influence the capture and distribution of prevailing winds. The results indicate that specific entrance geometries can significantly enhance ventilation efficiency by optimizing wind capture and distribution. The most effective designs demonstrated substantial improvements in air quality and thermal comfort, providing practical insights for subway systems in similar hot arid climates. The novelty of this research lies in its detailed analysis of architectural elements to leverage natural environmental conditions for improving indoor air quality and thermal comfort in public transit systems. The significance of this study is its contribution to the field of sustainable urban transport, offering a valuable framework for urban planners and engineers. By demonstrating how thoughtful design can lead to energy savings and enhanced passenger experiences, this research advances the discourse on sustainable urban infrastructure. This work not only enhances theoretical understanding but also provides actionable recommendations for creating more sustainable and comfortable public transit infrastructures.