Double-diffusive magneto-natural convection of nanofluid in an enclosure equipped with a wavy porous cylinder in the local thermal non-equilibrium situation

Abstract

The emphasis of this study is the numerical analysis via finite volume method of magneto-natural convection induced by double-diffusion of a nanofluid within an enclosure equipped with a wavy porous cylinder. The porous cylinder which is under the local thermal non-equilibrium (LTNE) situation is modeled using Darcy-Brinkman-Forchheimer design as momentum equation. Results are interpreted and evaluated in terms of the dimensionless controlling variables such as Rayleigh number (Ra), Lewis number (Le), Hartman number (Ha), buoyancy ratio parameter (N), Darcy number, (Da), and medium's porosity (ε) at a given heat transfer coefficient for the solid/fluid inter-phase (H) and modified conductivity ratio (γ) of the porous wavy cylinder region. Corcione's correlations with 4% of Al2O3 nanoparticles is used to estimate nanofluid's thermal conductivity and viscosity. Findings show that the heat and mass transfers are improved by Ra, Da, and ε augmentation and Ha and Le diminution. In general, as Le increases, the mass transfer rate rises while the corresponding heat transfer rate drops. Also, we identified a value of N where Le-dependent heat and mass transfer rates are minimal. Moreover, the heat transfer rate is found to be more sensitive to the changes in the porous medium's properties of the wavy porous cylinder than the mass transfer rate. Furthermore, the LTNE situation everywhere exists in the porous wavy cylinder except for the center where the LTE is realized.