Hall effects on unsteady hydromagnetic flow induced by an eccentric–concentric rotation of a disk and a fluid at infinity

The unsteady hydromagnetic flow of a viscous incompressible electrically conducting fluid induced by a sudden coincidence of two axes of rotation while a disk and the fluid at infinity are initially rotating with the same angular velocity about non-coincident axes in the presence of an axial uniform magnetic field has been examined considering the Hall effects. An exact solution of the governing equations has been obtained by the Laplace transform technique. The asymptotic behavior of the flow has been analyzed for small as well as large times to highlight transient approach to the steady state flow. It is found that the velocity components increase with an increase in Hall parameter. It is also found that for large time the steady state is reached through inertial oscillations. It is found that the solution for small values of time converges more rapidly than the general solution.