Abstract
The problem of natural convection flow and heat transfer of micropolar nanofluid inside a rectangular enclosure saturated with anisotropic porous medium is investigated numerically. All the walls of the enclosure are adiabatic except the bottom wall, which is partially heated and cooled by sinusoidal temperature profiles. An Al2O3/water nanofluid model has been utilized into the micropolar theory with experimental forms of thermo-physical nanofluid properties for both situations of hydrodynamically isotropic and anisotropic medium. The mathematical model of the proposed micropolar nanofluid flow regime consists of a set of partial differential equations along with the corresponding boundary conditions and these equations were solved numerically using the finite volume method with SIMPLE algorithm. The obtained results are presented in terms of streamlines and isotherms as well as local Nusselt number. It is found that a good enhancement in the rate of heat transfer can be obtained by increasing the nanoparticle volume fraction. For the anisotropic porous medium case, the increase in the permeability ratio leads to decrease the fluid activity, vortex strength, and the flow direction is reversed.