Document Type : Research Paper
Department of Chemical Engineering
Department of Mechanical Engineering
In this study, the three-dimensional magnetohydrodynamic (MHD) boundary layer of stagnation-point flow in a nanofluid was investigated. The Navier–Stokes equations were reduced to a set of nonlinear ordinary differential equations using a similarity transform. The similarity equations were solved for three types of nanoparticles: copper, alumina and titania with water as the base fluid, to investigate the effect of the nanoparticle volume fraction parameter (ϕ), the magnetic parameter (M), the Prandtl number (Pr) and the velocity ratio parameter (ε) on the flow and heat transfer characteristics. The skin-friction coefficient and Nusselt number as well as the velocity and temperature profiles for some values of the governing parameters were presented graphically and discussed. Effects of the solid volume fraction on the flow and heat transfer characteristics were thoroughly examined. It was observed that, for all three nonoparticles, the magnitude of the skin friction coefficient and local Nusselt number increases with enhancement in the nanoparticle volume fraction (ϕ). In addition, the velocity of fluid increases by increasing M and ε and the temperature increases by decreasing M, ε and Pr. The highest values of the skin friction coefficient and the local Nusselt number were obtained for the Cu nanoparticles compared to Al2O3 and TiO2.