MADACI Younes Taki EddineOTMANI.A (Encadrant)2025-11-182025-11-182025http://dspace.ensti-annaba.dz:4000/handle/123456789/962This thesis presents a CFD-based study on improving passive cooling of photovoltaic (PV) modules using natural convection. Different configurations were simulated, including increased water layer volume, cylindrical water channels, and replacement of water with phase change material (PCM) and moist sand. Results showed that moist sand provided the best thermal regulation due to its high thermal inertia and evaporation effect. The numerical model was experimentally validated, confirming the reliability of the simulations. The study highlights cost-effective, energy-free solutions for efficient PV cooling.enThesis