Natural convection of CuO-water micropolar nanofluids inside a porous enclosure using local thermal non-equilibrium condition

Abstract

Abstract The present paper deals with numerical investigation of natural convection of a micropolar nanofluid inside a porous enclosure using thermal non-equilibrium model. Rates of the heat transfer and micropolar nanofluid flow are widely considered by presenting contours of nanofluid flow, isotherms of fluid and solid phases, and contours of micro-rotation. Numerical results have been validated with previous references and good concordance has been observed. The results confirm that the thermal non-equilibrium model of the porous medium approaches the thermal equilibrium one by increasing thermal conductivity ratio parameter as well as the heat transfer interface parameter. The strength of convection inside pores of porous medium arises from augmenting H that can result in micro-rotations amplification. The characteristic equations of a micropolar fluid flow are transformed into classic Navier–Stokes equations by increasing porosity and the dimension of pores. Results indicate that the reduction of the thermal resistance of the fluid phase due to an increment of Kr can enhance the heat transfer rate through porous media. Finally, the permeability is important and influences the Nusselt numbers of both the solid matrix and the nanofluid when the nanofluid particles rotate around the center of their gravity.