A Numerical Study on Natural Ventilation Using a Horizontal Solar Chimney with a Bell-Mouth Inlet and Major Geometric Modifications

A numerical study was conducted to examine the natural ventilation performance of a horizontal solar chimney connected to a confined space. The study analyzed the impact of geometric modifications on the air mass flow rate. Four designs were examined using the Computational Fluid Dynamics (CFD) model: a Base Case (BC), a Radius Elbow (RE), a Bell Mouth (BM), and a combined Bell Mouth and Radius Elbow (BMRE). The BM inlet and the RE, significantly improved aerodynamic efficiency by reducing flow separation and pressure losses. The BMRE design reached the highest air mass flow rate of approximately 0.0425 kg/s at a heat flux of 800 W/m², which is a significant increase compared to the BC's flow rate of 0.039 kg/s. These results confirm that optimizing the geometries of the inlet and elbow can improve the efficiency of passive solar ventilation systems.