MPIDS Colloquium: Extreme Magnetoconvection

Extreme magnetoconvection is the thermal convection in an electrically conducting fluid (for example, a liquid metal) that occurs in the presence of an imposed magnetic field. We analyze this phenomenon computationally with the focus on the case of very strong static fields (the Hartmann number up to 1e4) and strong heating (the Grashof number up to 1e12). Our goals are to understand the nature of the flow and to explore the implications for the design of liquid metal blankets of tokamak fusion reactors and other liquid metal systems. It is found that, as the intense Joule dissipation of induced electric cur-rents suppresses conventional turbulence, the flows begin to demonstrate extreme, unusual and coun-ter-intuitive behaviors, such as slow oscillation of remarkably high amplitudes, quasi-two-dimensional chaotic regimes, or exponentially growing elevator modes.