MIXED CONVECTION MHD FLOW OF NANOFLUID OVER A NON-LINEAR STRETCHING SHEET WITH EFFECTS OF VISCOUS DISSIPATION AND VARIABLE MAGNETIC FIELD

The present paper deals with an analytical and numerical study of mixed convection taking into account the effects of MHD flow of nanofluid over a non-linear stretching sheet and viscous dissipation . The nanofluid is made of such nanoparticles as SiO 2 , TiO 2 , CuO and Ag with pure water as a base fluid. To analyze the problem, at first the boundary layer equations are transformed into non-linear ordinary equations using a similarity transformation. The resultant equations are then solved numerically using the Keller Box method based on the implicit finite-difference method. The effects of different non-dimensional governing parameters such as magnetic parameter, nanoparticles volume fraction, Nusselt, Richardson and Eckert numbers are investigated in details. The results indicate that, by adding the nanoparticles to the base fluids in forced, natural and mixed convection would cause the reduction in shear forces and a decrease in stretching sheet heat transfer coefficient. Also, in nanofluid decreasing of magnetic parameter and increasing Eckert number would result in better thermal conditions. In addition, using the Ag nanoparticles indicate better thermal conditions in comparison with other nanoparticles. DOI: http://dx.doi.org/10.5755/j01.mech.18.4.2334