Natural convection in a square cavity filled with a porous medium saturated with a nanofluid using the thermal nonequilibrium model with a Tiwari and Das nanofluid model

In this paper, natural convective heat transfer in a differentially heated square porous cavity filled with a nanofluid and using a two-temperature model for the heat transfer and the Tiwari and Das nanofluid model has been studied numerically. The two-temperature model employed allows us to analyze the fluid flow and heat transfer when the nanofluid and solid matrix are not in local thermal equilibrium. The boundary value problem formulated, in terms of the dimensionless stream function and temperature in the nanofluid and solid matrix, has been solved numerically using a second-order accurate finite difference method. Based on the results obtained, the adding of solid nanoparticles to the base fluid suppresses the convective flow. Further, it is concluded that the heat transfer in the nanofluid reduces as the the nanofluid/solid-matrix interface heat transfer parameter reduces. (C) 2015 Elsevier Ltd. All rights reserved.