Heat transfer and pressure drop characteristics of nanofluid in unsteady squeezing flow between rotating porous disks considering the effects of thermophoresis and Brownian motion

In this study, the unsteady three dimensional nanofluid flow, heat and mass transfer in a rotating system in the presence of an externally applied uniform vertical magnetic field is investigated. This study has different applications in rotating magneto-hydrodynamic (MHD) energy generators for new space systems and also thermal conversion mechanisms for nuclear propulsion space vehicles. The important effects of Brownian motion and thermophoresis have been included in the model of nanofluid. The governing equations are non-dimensionalized using geometrical and physical flow field-dependent parameters. The velocity profiles in radial, tangential and axial directions, pressure gradient, temperature and concentration distributions are obtained. The effects of different governing parameters namely: Reynolds number, rotation parameter, magnetic parameter, Prandtl number, Schmidt number, thermophoretic parameter and Brownian motion parameter on all nanofluid velocity components, temperature and concentration distributions, pressure gradient, Nusselt number and Sherwood number are displayed through tables and graphs and the results are discussed in detail. (C) 2016 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.