The problem of steady, laminar and incompressible double diffusive natural convection flow in a wavy thin layer is studied. The thin layer is assumed to be filled with water based nanofluid having different nanoparticles namely Ag and CuO. The study includes computations for different Dufour coefficient (Df = 0, 0.3, 0.6 and 1) and Soret coefficient (Sr = 0, 0.3, 0.6 and 1). The pressure-velocity form of Navier-Stokes equations, energy equation and concentration equation are used to represent the mass, momentum, energy and concentration conservations of the nanofluid medium in the layer. The governing equations and corresponding boundary conditions are converted to dimensionless form and solved numerically by penalty finite element method with discretization by triangular mesh elements with six nodes. Flow, heat and mass transfer characteristics are presented in terms of streamlines, isotherms and iso-concentrations. In addition, results for the average radiative, convective heat and mass transfer, mean temperature and concentration of nanofluid, mid height horizontal-vertical velocities and sub domain average velocity field are offered and discussed for the above mentioned parametric conditions. Results show that the effects of Df and Sr on the convective-radiative heat and mass transfer phenomenon inside the domain are significant for all values of Df and Sr studied. The code validation shows excellent concurrence with the hypothetical outcome obtainable in the literature.
buoyant convection, dufour-soret coefficients, finite element method, nanofluid having different nanoparticles, thin layer
 Hollands, K.G.T., Unny, T.E., Raithby, G.D., Konicek, L. Free convective heat transfer across inclined air layers (1976) Journal of Heat Transfer, 98 (2), pp. 189-193. doi: 10.1115/1.3450517
 Hetsroni, G., Rozenblit, R.Heat transfer to a liquid-solid mixture in a flume (1994) International Journal of Multiphase Flow, 20 (4), pp. 671-689. doi: 10.1016/0301-9322(94)90038-8
 Noorshahi, S., Hall, C.A., Glakpe, E.K. Natural convection in a corrugated enclosure with mixed boundary conditions (1996) Journal of Solar Energy Engineering, Transactions of the ASME, 118 (1), pp. 50-57. doi: 10.1115/1.2847946
 Stasiek, J.A. Experimental studies of heat transfer and fluid flow across corrugated-undulated heat exchanger surfaces (1998) International Journal of Heat and Mass Transfer, 41 (6-7), pp. 899-914. http://www.journals.elsevier.com/international-journal-of-heat-and-mass-transfer/ doi: 10.1016/S0017-9310(97)00168-3
 Hwang, Y., Lee, J.K., Lee, C.H., Jung, Y.M., Cheong, S.I., Lee, C.G., Ku, B.C., Jang, S.P. Stability and thermal conductivity characteristics of nanofluids (2007) Thermochimica Acta, 455 (1-2), pp. 70-74. doi: 10.1016/j.tca.2006.11.036
 Parvin, S., Nasrin, R., Alim, M., Hossain, N. Double-diffusive natural convection in a partially heated enclosure using a nanofluid (2012) Heat Transfer - Asian Research, 41 (6), pp. 484-497. doi: 10.1002/htj.21010
 Nasrin, R., Alim, M.A. Soret and Dufour effects on double diffusive natural convection in a chamber utilizing nanofluid (2012) International Journal of Heat and Technology, 30 (1), pp. 109-117. http://www.iieta.org/Journals/H%26TECH/CURRENT%20ISSUE
 Nasrin, R., Parvin, S. Hydromagnetic effect on mixed convection in a lid-driven cavity with sinusoidal corrugated bottom surface (2011) International Communications in Heat and Mass Transfer, 38 (6), pp. 781-789. doi: 10.1016/j.icheatmasstransfer.2011.03.002
 Nasrin, R. Laminar combined magnetoconvection in a wavy enclosure with the effect of heat conducting cylinder (2011) International Communications in Heat and Mass Transfer, 38 (9), pp. 1269-1278. doi: 10.1016/j.icheatmasstransfer.2011.06.005
 Nasrin, R.Influences of physical parameters on mixed convection in a horizontal lid-driven cavity with an undulating base surface (2012) Numerical Heat Transfer; Part A: Applications, 61 (4), pp. 306-321. doi: 10.1080/10407782.2012.647987
 Nasrin, R., Alim, M.A., Chamkha, A.J. Combined convection flow in triangular wavy chamber filled with water-CuO nanofluid: Effect of viscosity models (2012) International Communications in Heat and Mass Transfer, 39 (8), pp. 1226-1236. doi: 10.1016/j.icheatmasstransfer.2012.06.005
 Nasrin, R., Parvin, S. Investigation of buoyancy-driven flow and heat transfer in a trapezoidal cavity filled with water-Cu nanofluid (2012) International Communications in Heat and Mass Transfer, 39 (2), pp. 270-274. doi: 10.1016/j.icheatmasstransfer.2011.11.004
 Nasrin, R., Alim, M.A. Free convective flow of nanofluid having two nanoparticles inside a complicated cavity (2013) International Journal of Heat and Mass Transfer, 63, pp. 191-198. doi: 10.1016/j.ijheatmasstransfer.2013.03.068
 Nasrin, R., Alim, M.A. Dufour-Soret effects on natural convection inside a solar collector utilizing water-CuO nanofluid (2012) Int. J. Of Energy & Tech., 4 (23), pp. 1-10.
 Lin, K.C., Violi, A. Natural convection heat transfer of nanofluids in a vertical cavity: Effects of non-uniform particle diameter and temperature on thermal conductivity (2010) International Journal of Heat and Fluid Flow, 31 (2), pp. 236-245. doi: 10.1016/j.ijheatfluidflow.2009.11.003
 Saleh, H., Roslan, R., Hashim, I. Natural convection heat transfer in a nanofluid-filled trapezoidal enclosure (2011) International Journal of Heat and Mass Transfer, 54 (1-3), pp. 194-201. doi: 10.1016/j.ijheatmasstransfer.2010.09.053
 Pak, B.C., Cho, Y.I. Hydrodynamic and heat transfer study of dispersed fluids with submicron metallic oxide particles (1998) Experimental Heat Transfer, 11 (2), pp. 151-170. doi: 10.1080/08916159808946559
 Maxwell-Garnett, J.C. Colours in metal glasses and in metallic films (1904) Philos. Trans. Roy. Soc. A, 203, pp. 385-420.
 Taylor, C., Hood, P. A numerical solution of the Navier-Stokes equations using the finite element technique (1973) Computers and Fluids, 1 (1), pp. 73-100. doi: 10.1016/0045-7930(73)90027-3
 Dechaumphai, P. (1999) Finite Element Method in Engineering. 2nd ed., Chulalongkorn University Press, Bangkok
 Basak, T., Roy, S., Pop, I. Heat flow analysis for natural convection within trapezoidal enclosures based on heatline concept (2009) International Journal of Heat and Mass Transfer, 52 (11-12), pp. 2471-2483.doi: 10.1016/j.ijheatmasstransfer.2009.01.020
 Ogut, E.B. Natural convection of water-based nanofluids in an inclined enclosure with a heat source (2009) Int. J. Of Thermal Sciences, 48, pp. 1-11.
 Gao, W., Lin, W., Lu, E. Numerical study on natural convection inside the channel between the flat-plate cover and sine-wave absorber of a cross-corrugated solar air heater (2000) Energy Conversion and Management, 41 (2), pp. 145-151. doi: 10.1016/S0196-8904(99)00098-9
 Nithyadevi, N., Yang, R.-J.Double diffusive natural convection in a partially heated enclosure with Soret and Dufour effects (2009) International Journal of Heat and Fluid Flow, 30 (5), pp. 902-910. doi: 10.1016/j.ijheatfluidflow.2009.04.001