Heat transfer performance of MHD water based metal oxide nanofluids in a Darcy–Forchheimer porous medium

This study numerically investigates the radiative magnetohydrodynamic (MHD) boundary layer flow and heat transfer characteristics of a water based quaternary nanofluid containing CuO, TiO 2 , Al 2 O 3 and SiO 2 nanoparticles over a linearly stretching sheet embedded in a Darcy Forchheimer porous medium. The model incorporates the simultaneous effects of magnetic field, nonlinear inertial drag, thermal radiation, Joule heating and internal heat generation/absorption. Appropriate similarity transformations reduce the governing nonlinear partial differential equations into a coupled system of ordinary differential equations, which are solved using the Keller box method. The numerical results reveal that increasing magnetic parameter, porous resistance and Forchheimer number suppress the velocity field, whereas radiation and heat source parameters enhance the temperature distribution and thicken the thermal boundary layer. Variations in the skin friction coefficient and Nusselt number are evaluated to quantify surface drag and heat transfer performance. A multilinear regression analysis is further employed to statistically support the numerical findings. The outcomes demonstrate that the proposed quaternary nanofluid provides improved thermal characteristics and has potential applications in porous heat exchangers, solar thermal systems, electronic cooling and MHD based thermal management technologies.