Abstract:
The time-dependent collapse of a slender flux tube extending vertically in the convection zone of the sun is modelled. Starting from an initial state in which the flux tube is in hydrostatic equilibrium, the non-linear MHD equations are used to examine its temporal evolution. A detailed study of the flow variables and magnetic field within the tube is presented. It is seen that asymptotically in time a unique state of dynamic equilibrium is established, irrespective of the value of beta-O (the ratio of the thermal to magnetic pressure at the initial epoch).