EFFECT OF SUSPENSED PARTICLES, MAGNETIC FIELD AND ROTATION ON THERMAL STABILITY OF FERROMAGNETIC FLUIDS

摘要

The effect of suspended particles, magnetic field, magnetization and rotation on the thermal stability of a ferromagnetic fluid heated from below is considered. Using a linearized stability theory and normal mode analysis for a fluid layer between two free boundaries, an exact solution is obtained. A dispersion relation governing the effects of suspended particles, magnetic field, magnetization and rotation is derived. For the case of stationary convection, it is found that a suspended particle has a destabilizing effect whereas rotation and magnetization have a stabilizing effect on the system. The magnetic field has a stabilizing effect on the system under certain conditions. The effects of various parameters on the thermal stability are depicted graphically also and the results are in agreement with analytical solutions. The principle of exchange of stabilities is found to hold true for the ferromagnetic fluid heated from below in the absence of rotation and the magnetic field. The oscillatory modes are introduced due to the presence of rotation and the magnetic field which were non-existent in their absence.