This study presents a simplified, CFD-independent numerical model to evaluate the thermal and fluid-dynamic performance of a solar chimney system (SCS) integrated with a NiO–CuO nano-coated absorber. The model combines optical absorption, absorber energy balance, buoyancy-driven flow, and exergy analysis to generate twelve interlinked datasets representing velocity, pressure, absorber temperature, heat gain, density variation, air temperature rise and exergy behaviour under irradiance levels of 400–1000 W/m². A temperature-dependent absorptance (0.93–0.96) for NiO–CuO nanocoating is incorporated to capture enhanced photothermal behaviour. The research results revealed that the nano-coated absorber achieves 6–12 °C higher plate temperature, 18–32% higher air velocity, 22–35% higher draft pressure, and the exergy efficiency increases from 2–8% (uncoated) to 4–11% (coated), indicating a significant thermodynamic improvement. Contour maps confirm superior radial and axial heat distribution for the nano coated case. The proposed numerical framework is computationally efficient, physically consistent, and suitable for predicting performance improvements in nano-enhanced solar chimney systems for ventilation, drying, and passive heating applications.
