Mahmoudi A.,Ur Unite Of Recherche |
Mejri I.,Ur Unite Of Recherche |
Abbassi M.A.,Ur Unite Of Recherche |
Omri A.,Ur Unite Of Recherche
Journal of Molecular Liquids | Year: 2014
This paper examines the natural convection in a square enclosure filled with a water-Al2O3 nanofluid in the presence of magnetic field and uniform heat generation/absorption. The left wall is hot, the right wall is cold and the horizontal walls are insulated. Lattice Boltzmann method (LBM) is applied to solve the coupled equations of flow and temperature fields. The entropy generation due to heat transfer, fluid friction and magnetic effect has been determined by the finite difference method. This study has been carried out for the pertinent parameters in the following ranges: Rayleigh number of the base fluid, Ra = 103 to 106, Hartmann number varied from Ha = 0 to 60, heat generation/absorption coefficient q = - 10 to 10 and the solid volume fraction of nanoparticles between φ= 0 and 6%. For Ra 10;bsupesup& and Ha 30, the results show that the heat generation/absorption coefficient influences heat transfer rate, but it does not affect the entropy generation in the range - 10 < q < 5. Also it is observed that adding nanoparticle reduces the entropy generation. The nanoparticle effect is more intense for high Hartmann number. © 2014 Elsevier B.V.