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ISSN Online: 2377-424X

International Heat Transfer Conference 12
August, 18-23, 2002, Grenoble, France

Natural convection in a vertical enclosure under a strong and uniform magnetic field

Get access (open in a dialog) DOI: 10.1615/IHTC12.3850
6 pages

摘要

In the presence of a uniform horizontal magnetic field, some characteristics of the convective flows in a vertically long rectangular enclosure, with two isothermal and four adiabatic walls are presented analytically and numerically. Since the electric current must close up within the liquid metal, high intensity of electric current may pass in the vicinity of the insulating walls. When these walls are perpendicular to the magnetic field, the corresponding Hartmann layers impose their own electric potential to the core, and take the control of the core flow.T his significant property that the Hartmann layers may become active and the resulting core flow rate being proportional to the electric current, cannot be numerically well represented because of the thickness of the Hartmann layer. But the well known analytical solution in these layers allows taking directly their influence via new boundary conditions for the core flow.T his modeling of the new boundary conditions saves important memory and CPU resources, and its solution is much closer to the true solution. Considering the properties of both Hartmann and side layers, when the heat flux and the magnetic field are parallel, we find inactive Hartmann layers and therefore very low velocities in the core (Gr/Ha2), with high velocities in 'jet side layers'. On the other hand, when they are perpendicular, the electric current density in the Hartmann layer is Ha times larger than in the core, and the velocity is scaled as Gr/Ha, masking the jet effect in the side layers.W e have confirmed that the corresponding analytical solutions in the limit of the conductive temperatures agree with the numerical solutions.