The rapid advancement of nanotechnology has enabled the engineering of advanced fluids with superior transport characteristics, particularly for thermal and mass transfer applications. This study investigates the complex behavior of a trihybrid nanofluid \(\left( {Cu - Al_{2} O_{3} - TiO_{2} /H_{2} O} \right)\) flow over a stretching sheet, motivated by the need to enhance the performance of solar water pumping systems (SWPS) used in irrigation, groundwater extraction, and remote water supply. The model incorporates multiple physical effects including electroosmotic force, transverse magnetic field, Darcy–Forchheimer porous medium resistance, solar radiation, activation energy, and Soret and Dufour effects—reflecting a highly coupled, real-world scenario. The governing nonlinear partial differential equations are transformed using similarity variables and solved numerically using MATLAB’s bvp4c solver combined with the shooting method for improved accuracy. To understand the system's thermodynamic performance, entropy generation analysis is employed. Furthermore, linear and quadratic regression models, along with sensitivity analysis and ANOVA, are conducted to statistically validate the influence of key parameters on heat and mass transfer. The results reveal that trihybrid nanofluids yield a 34.03% improvement in heat transfer and a 29.45% increase in mass transfer efficiency compared to conventional nanofluids. The synergistic effects of magnetic field, electroosmosis, and nanoparticle interactions significantly enhance energy transport characteristics. This work is novel in its comprehensive integration of multi-parameter physics and statistical validation in trihybrid nanofluid -based flow modeling, offering critical insights for optimizing solar water pumping systems (SWPS) efficiency in sustainable energy and agricultural systems.
