Ferrohydrodynamic instability of a viscoelastic magnetic fluid layer under the influence of time-varying magnetic field

The current work concerns the impact of a time-varying magnetic field on the threshold of Oldroyd-B viscoelastic magnetic fluid convection in the presence of both modulated and unmodulated magnetic fields. A time-varying magnetic field plays a crucial role in creating circulation in small passages where the effect of gravity is absent or ineffective. The resulting eigenvalue problem is obtained by a regular perturbation expansion under the assumption of a small modulation amplitude. The impact of the magnetic parameter, Prandtl number, stress relaxation parameter, strain retardation parameter and magnetic field modulation frequency, were discussed. The study shows that, the magnetic field modulation has a destabilizing impact on the system with convection occurs faster.