Structure of the wake of a magnetic obstacle.

We use a combination of numerical simulations and experiments to elucidate the structure of the flow of an electrically conducting fluid past a localized magnetic field, called magnetic obstacle. We demonstrate that the stationary flow pattern is considerably more complex than in the wake behind an ordinary body. The steady flow is shown to undergo two bifurcations (rather than one) and to involve up to six (rather than just two) vortices.

Influence of the thermoelectric effect on the Rayleigh-Bénard instability inside a magnetic field.

We investigate the influence of thermoelectric effect on the onset of thermal instability in the Rayleigh-Bénard system with vertical magnetic field. An electrically conducting fluid is confined in an infinite horizontal layer between thick thermally and electrically conducting walls. A horizontal temperature variation resulting from convective instability leads to horizontal temperature gradients along the liquid-solid interface acting as a source of thermoelectric currents.