Abstract: Free convection in hybrid nanomaterial-saturated permeable media is crucial in various engineering applications. The present study aims to investigate the free convection of an aqueous-based hybrid nanomaterial through a zone under the combined effect of the Lorentz force and radiation. The natural convection of the hybrid nanomaterial is modeled by implementing a control volume finite element method (CVFEM)-based code, whereas Darcy assumptions are used to model the porosity terms in the momentum buoyancy equation involving the average Nusselt number Nu_ave, flow streamlines, and isotherm profiles. A formula for estimating Nu_ave is proposed. The results show that the magnetic force retards the flow, and the fluid tends to attract the magnetic field source. Nu_ave is directly correlated with the Rayleigh number and radiation; however, it is indirectly dependent on the Hartmann number. Conduction is the dominant mode at larger Darcy and Hartmann numbers.

Key words: free convection, hybrid nanoparticle, Darcy porous space, Hartmann number, radiation