Natural convection of magnetic hybrid nanofluid inside a double-porous medium using two-equation energy model

Porous media and nanofluids can be used for heat transfer enhancement in different industrial sectors. Very often technical systems consist of several porous layers. At the same time, hybrid nanofluids can be more effective in comparison with a nanofluid including only one kind of nanoparticles. The present study deals with a numerical analysis of MHD hybrid nanofluid natural convection heat transfer within the T-shaped cavity heated from the bottom and cooled from the upper chamber walls. Two different porous layers form the considered enclosure. The viscosity of the nanofluid depends on the magnetic field intensity. Governing equations written in dimensionless primitive variables using the extended Darcy-Brinkman-Forchheimer model for the porous medium, single-phase nanofluid model and local thermally non-equilibrium model were solved by the finite element method. Wide-range governing parameters impacts were examined to define the development of nanofluid flow and heat transfer inside the enclosure. Heat transfer enhancement can be gained for low values of the solid-liquid interface convection parameter, magnetic field viscosity parameter and high values of the thermal conductivity ratio. (C) 2019 Elsevier B.V. All rights reserved.