Convective heat transport in a porous wavy enclosure: Nonuniform multi-frequency heating with hybrid nanofluid and magnetic field

This work investigates the dynamics of the hybrid nanofluidic convective heat transfer in a permeable thermal system under the influence of multifrequency heating and a magnetic field. The geometry comprises a wavy-walled cavity filled with a water-based hybrid nanoliquid (Al2O3–Cu–H2O) in a saturated porous medium. The finite volume approach is applied to scrutinize the hydro-thermal characteristics resulting from bottom heating and side cooling, considering various flow-controlling parameters. The analysis reveals that nonuniform multi-frequency heating can be a highly effective strategy for enhancing heat transfer in complex geometries involving porous systems, nanofluid flow, and magnetic fields. Significant heat transfer improvement is observed at higher frequencies, with an increase of approximately 261.49 % when offset temperatures are introduced. Additionally, an increase in the undulation height of the wavy sidewalls contributes to a partial heat transfer improvement of 13.41 % compared to the case without undulations. The influence of the Darcy number, Hartmann number, porosity index, and nanoparticle concentration on heat transfer performance is also investigated. Higher Darcy and Hartmann numbers result in reduced thermal convection, while increased porosity enhances thermal convection. Elevated nanoparticle concentrations weaken the flow strength due to higher viscosity. System engineers can optimize heat transfer systems in their respective applications by comprehending the interactions between these flow-controlling parameters. This work contributes to a deeper understanding of the hydro-thermal phenomena in a multiphysics problem and provides a foundation for the development of more efficient heat transfer systems.