Convective-heat transfer of magnetic-sensitive nanofluids in the presence of rotating magnetic field

In this work, forced-convection heat transfer of magnetic-sensitive nanofluids has been investigated in the presence of rotating magnetic field. In this regard, the laminar, Newtonian, incompressible, and two-dimensional (2D) fluid flow in a horizontal duct subject to constant wall temperature boundary condition was modeled. Moreover, the fluid was supposed to be non-electrical conductive and the magnetic field source comprised of two time varying components perpendicular to each other. Influences of magnetic field intensity and frequency, inlet fluid velocity, and spin viscosity on the forced-convection heat transfer of the magnetic nanofluids were investigated. It was found that the applied magnetic field can change the velocity distribution from the parabolic to sinusoidal shape and the average Nusselt number has an optimum value in terms of the magnetic field intensity, frequency, and spin viscosity. For a given magnetic field specification and a fixed ferrofluid, the influence of magnetic field on the Nusselt number value decreases with an increase in the fluid inlet velocity. (C) 2017 Elsevier Ltd. All rights reserved.