The effects of Ohmic heating and viscous dissipation on unsteady MHD and slip flow over a porous rotating disk with variable properties in the presence of Hall and ion-slip currents

The effects of Ohmic heating and viscous dissipation on unsteady laminar magneto-hydrodynamics (MHD) flow of a viscous Newtonian and electrically conducting fluid over a rotating disk taken into account the variable fluid properties (density, (?), viscosity, (µ) and thermal conductivity, (?)) in the presence of Hall and ion-slip currents effects have been examined. These fluid properties are taken to be dependent on temperature. The unsteady Navier-Stokes equations along with the energy equation are reduced to a system of ordinary differential equations by using similarity transformations and the resulting equation system is solved numerically by using a shooting method. Results for the details of the velocity as well as temperature are shown graphically and the numerical values of the skin friction and the rate of heat transfer are entered in tables. © 2007 Elsevier Ltd. All rights reserved.