Validity of quasi-2D models for magneto-convection

L. Bühler¹ - C. Mistrangelo¹ - S. Molokov²

¹ Karlsruhe Institute of Technology (KIT), Postfach 3640, 76021 Karlsruhe, Germany
² Coventry University, Priory Street, Coventry CV1 5FB, UK

Abstract
For applications in nuclear fusion reactors where magnetic fields are very strong, liquid metal flows in the cores of ducts can often be regarded as inertialess and practically inviscid, while viscous effects are localized in thin boundary layers. The intense electromagnetic Lorentz forces, resulting from the interaction of induced electric currents and imposed magnetic field, tend to remove flow variations along magnetic field lines and they force the fluid to circulate mainly in planes perpendicular to the field. The established quasi-two dimensional magnetohydrodynamic flow can be predicted by means of an approximate model by reducing the basic governing equations to a 2D problem by analytical integration along magnetic field lines. Such models have been applied in the past by numerous authors to investigate duct flow problems and magneto-convection. However, limitations of those Q2D approaches have never been systematically studied. Figs 6, Refs 14.