Effects of homogeneous-heterogeneous reactions in flow of magnetite-Fe3O4 nanoparticles by a rotating disk

This article addresses the flow of ferrofluid due to a rotating disk in the presence of homogeneous-heterogeneous reactions. The disk rotates with constant angular velocity about the z-axis. Water is used as base fluid while magnetite-Fe3O4 as nanoparticle. Fluid is electrically conducting in the presence of an applied magnetic field. Effects of viscous dissipation are also considered. The disk is kept at uniform temperature while there is ambient temperature away from the disk. In view of the rotational symmetry, the derivatives in the azimuthal direction are neglected. Appropriate transformations reduce the system of nonlinear partial differential equations to system of ordinary differential equations. Convergent series solutions are computed using homotopy analysis method (HAM) for the resulting nonlinear problems. Effects of different parameters on the velocity, temperature and concentration profiles are shown and analyzed. Computations for skin friction coefficient and Nusselt number are presented and examined for the influences of pertinent parameters. It is noted that concentration distribution decreases for larger values of strength of homogeneous reaction parameter while it increases for strength of heterogeneous reaction parameter. Skin friction coefficient and rate of heat transfer are enhanced when the strength of magnetic field is increased. (C) 2016 Elsevier B.V. All rights reserved.