Unsteady flow and heat transfer of the ferrofluid between two shrinking disks under the influence of magnetic field

The unsteady flow of the ferrofluid between two rotating and contracting disks has been investigated in the presence of a uniform magnetic field. A similarity transformation is used to convert the governing partial differential equations into a set of nonlinear ordinary differential equations. The transformed system is then solved numerically through mathematical modelling in COMSOL Multiphysics in a framework of the finite element method. Effect of shrinking of the disks, magnetisation force, injection parameter, rotation of the disk, variation in the temperature of the bottom disk, Prandtl number and Eckert number are studied on the radial velocity, tangential velocity, axial velocity and temperature distributions. The error in the previous mathematical model for rotational flow is also rectified in the present model. (author)