Localised Oscillatory States in Magnetoconvection

Дата и время публикации : 2013-02-01T19:38:17Z

Авторы публикации и институты :
Matthew C. Buckley
Paul J. Bushby

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: 12 pages, 14 figures, 2 tables
Первичная категория: astro-ph.SR

Все категории : astro-ph.SR

Краткий обзор статьи: Localised states are found in many pattern forming systems. The aim of this paper is to investigate the occurrence of oscillatory localised states in two-dimensional Boussinesq magnetoconvection. Initially considering an idealised model, in which the vertical structure of the system has been simplified by a projection onto a small number of Fourier modes, we find that these states are restricted to the low $zeta$ regime (where $zeta$ represents the ratio of the magnetic to thermal diffusivities). These states always exhibit bistability with another non-trivial solution branch, in other words they show no evidence of subcritical behaviour. This is due to the weak flux expulsion that is exhibited by these time-dependent solutions. Using the results of this parameter survey, we locate corresponding states in a fully-resolved two-dimensional system, although the mode of oscillation is more complex in this case. This is the first time that a localised oscillatory state, of this kind, has been found in a fully-resolved magnetoconvection simulation.

Category: Physics