Augmentation of natural convective heat transfer in linearly heated cavity by utilizing nanofluids in the presence of magnetic field and uniform heat generation/absorption

In this numerical work, MHD natural convection of Cu-water nanofluid and pure water in a cavity with the left wall being linearly heated is analyzed using the Lattice Boltzmann Method (LBM). The effective thermal conductivity and viscosity of nanofluid are calculated by the Maxwell-Garnetts (MG) and Brinkman models, respectively. The influence of pertinent parameters such as Hartmann number (Ha = 0-60), Rayleigh number (Ra = 10(3)-10(6)), heat generation or absorption coefficient (q = -10, -5, 0, 5, 10) and nanopartide volume concentration (phi = 0-0.05) on the flow and heat transfer characteristics has been examined. The results show that the heat transfer increases with an increase of the Rayleigh number and decreases with an increase of the Hartmann number. In addition, the results show that the heat generation or absorption coefficient has a significant effect on the streamlines, isotherms and vortex formation in the enclosure. Moreover, the increase of nanoparticles volume fraction has a positive impact on the average Nusselt number. (C) 2015 Elsevier B.V. All rights reserved.