Second law analysis of a 3D magnetic buoyancy-driven flow of hybrid nanofluid inside a wavy cubical cavity partially filled with porous layer and non-Newtonian layer

The current paper presents numerical results of the 3D buoyancy-driven flow of a hybrid nanofluid in a cubical cavity in the presence of a magnetic field. The computational domain comprises two layers: a non-Newtonian fluid layer and a hybrid nanofluid layer. The temperature disparity within the domain results from heating the wavy bottom wall and cooling both sidewalls while the top wall is insulated. A magnetic field is applied on the positive z-axis. To encounter the non-Newtonian layer influence, the power-law model is considered. The solution of the governing equations is obtained by the Galerkin FEM method. The effects of geometrical parameters of the problem are discussed and illustrated. The results indicate that by simultaneously using non-Newtonian Fe3O4/MWCNT hybrid nanofluid and porous media, the heat exchange in the 3-D cavity is positively affected by the growth in Rayleigh number, Darcy number as well as the height of the porous layer. Furthermore, it is negatively affected by the rise of the magnetic field, corrugation number, and a minor degree when the flow index n was increased due to the pseudo-plastic fluid's high viscosity and shear force.