Linear stability of thermocapillary convection in cylindrical liquid bridges under axial magnetic fields

The stability of axisymmetric steady thermocapillary convection of electric ally conducting fluids in half-zones under the influence of a static axial magnetic field is investigated numerically by linear stability theory. In a ddition, the energy transfer between the basic state and a disturbance is c onsidered in order to elucidate the mechanics of the most unstable mode. Ax ial magnetic fields cause a concentration of the thermocapillary how near t he free surface of the liquid bridge. For the low Prandtl number fluids con sidered, the most dangerous disturbance is a non-axisymmetric steady mode. It is found that axial magnetic fields act to stabilize the basic state. Th e stabilizing effect increases with the Prandtl number and decreases with t he zone height, the heat transfer rate at the free surface and buoyancy whe n the heating is from below. The magnetic field also influences the azimuth al symmetry of the most unstable mode.