Analysis of Thermomagnetic Convection in a Vertical Layer of Ferromagnetic Fluid under Inclined Magnetic Field

Abstract

The main purpose of this study is to deal with the magneto-gravitational convection in a layer of ferromagnetic fluids between two vertical non-magnetic plates. One of the plates is kept at constant temperature. A uniform inclined external magnetic field under nonzero gravity conditions has been considered. In this research both the gravitational and magnetic effects are taken into account. Two distinct mechanisms, namely, thermogravitational(buoyancy-driven) and thermomagnetic, lead to the apprearance of various instability modes. The characteristics of all instability modes are investigated. The three types of instability patterns relating to thermogravitational, magnetic and magnetogravitational convection are found to exist in a normal magnetic field. The inclined external magnetic field conducts the preferential change of instability structures toward the hot wall, it induces an asymmetry with the problem, and then it brings qualitative change in the stability characteristics. It is found because of the angle of inclination of the magnetic field, where a preferred magnetic field is kept in an orientation angle that introduces maximum magneto-gravitational instability. The destabilizing effects due to thermal disturbances and the variation of fluid magnetization has been found in the flow domain. However, the related variation of a magnetic field can draw the energy from the perturbed flow field, which is depending on the orientation of the applied field thus playing a stabilizing role. The role of the buoyancy effects shifts from destabilizing in the gravity-dominated flow to stabilizing in flows with strong magnetic effects is also found.