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In the present study, natural convection of nanofluids in a concentric horizontal annulus enclosure has been numerically simulated using the lattice Boltzmann method. A water-based nanofluid containing Al2O3 nanoparticle has been studied. Simulations have been carried while the Rayleigh number ranges from 103 to 105 and solid volume fraction varies between 0 and 0.04. The effects of solid volume fraction of nanofluids on hydrodynamic and thermal characteristics such as average and local Nusselt numbers, streamlines and isotherm patterns for different values of solid volume fraction, annulus gap width ratio and Rayleigh number are investigated and discussed in detail.
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 Kuehn, T., Goldstein, R., A parametric study of Prandtl number and diameter ratio effects on natural convection heat transfer in horizontal cylindrical annuli, J. Heat Transfer, 102 (1978), pp.768-770.
 Glapke, E.K., et al., Constant heat ﬂux solutions for natural convection between concentric and eccentric horizontal cylinders, Numer. Heat Transfer, 10 (1986), pp. 279-295.
 Guj, G. S., et al, Experimental Analysis of Thermal Fields in Horizontally Eccentric Cylindrical Annuli, Exp. Fluid., 12 (1992), pp.385-393.
 Choi, U.S., Enhancing thermal conductivity of fluids with nanoparticles, Developments and application of non-Newtonian flows, ASME, 66 (1995), pp. 99-105.
 Oztop, H.F., Abu-Nada, E., Numerical study of natural convection in partially heated rectangular enclosures filled with nanofluids, Int. J. Heat Fluid Flow, 29 (2008), pp. 1326-1336.
 Abu-Nada, E., et al., Natural convection heat transfer enhancement in horizontal concentric annuli using nanofluids. Int. Commun. Heat Mass Transfer, 35 (5) (2008), pp. 657–665.
 Sheikhzadeh, G. A., et al., Laminar natural convection of Cu-water nanofluid in concentric annuli with radial fins attached to the inner cylinder, Int J Heat Mass Tran., 49 (3) (2013), pp. 391-403.
 Khanafer, K., and Vafai, K., A critical synthesis of thermophysical characteristics of nanofluids, International Journal of Thermal Sciences, 49 (2010), pp. 2339-2352
 Salari, M., et al., MIXED CONVECTION OF NANOFLUID FLOWS IN A SQUARE LID- DRIVEN CAVITY HEATED PARTIALLY FROM BOTH THE BOTTOM AND SIDE WALLS, Numerical Heat Transfer, Part A, 62 (2012), pp. 158–177.
 Salari, M., et al., Numerical solutions to heat transfer of nanofluid flow over stretching sheet subjected to variations of nanoparticle volume fraction and wall temperature, Appl. Math. Mech.- Engl. Ed., 35(1) (2014), pp. 63–72.
 Fattahi, E., et al., Lattice Boltzmann simulation of mixed convection heat transfer in eccentric annulus, Int Communc Heat Mass., 38 (2011), pp. 1135–1141.
 Nemati, H., et al., Lattice Boltzmann simulation of nanofluid in lid-driven cavity, Int. J. Heat Mass Transfer, 37 (2010), pp. 1528–1534.
 Nemati, H., et al., Magnetic field effects on natural convection flow of nanofluid in a rectangular cavity using the Lattice Boltzmann model, Scientia Iranica, 19 (2012), pp. 303–310.
 Fattahi, E., et al., Lattice Boltzmann simulation of natural convection heat transfer in nanofluids, Int. J. Thermal Sci., 52 (2012), pp. 137–144.
 Mei, R., et al., Force evaluation in the lattice Boltzmann method involving curved geometry, Phys. Rev. E, 65 (2002), pp. 1–14.
 Fallah, K., et al., Multiple-relaxation-time lattice Boltzmann simulation of non-Newtonian flows past a rotating circular cylinder, J NON-NEWTON FLUID, 177-178 (2012), pp. 1–14.
 Fallah, K., et al., Numerical simulation of planar shear flow passing a rotating cylinder at low Reynolds numbers, Acta Mech., 223 (2012) 221–236.
 Fallah, K., et al., Simulation of planar shear flow passing two equal sized circular cylinders in tandem arrangement, in: AIP Conf. Proc., 1400, 2011, pp. 449–452.
 Yan, Y.Y., Zu, Y.Q., Numerical simulation of heat transfer and ﬂuid ﬂow past a rotating isothermal cylinder_a LBM approach, Int J of Heat Mass Tran., 51(2008), pp. 2519–2536.
 Chon, C.H., et al., Empirical correlation ﬁnding the role of temperature and particle size for nanoﬂuid (Al2O3) thermal conductivity enhancement, Appl. Phys. Lett., 87 (15) (2005), pp. 153107.
 Saha, L.K., et al., Effect of Hall current on the MHD laminar natural convection flow from a vertical permeable flat plate with uniform surface temperature, Int. J. Thermal Sci., 46 (2007), pp. 790-801.
 Minsta, H.A., et al., New temperature and conductivity data for water-based nanoﬂuids, Int. J. Thermal Sci., 48 (2) (2009), pp. 363–371.