Here, an original rotating permanent magnet (RPM) system placed coaxially with the liquid metal container is studied as an effective means of generating flow in shallow cylinders for potential application in aluminum metallurgy (e.g., for ladle stirring and metal dosing). The studied RPM system generates volume force with strong axial variation and force maximum near the radial midpoint. The numerical and experimental data show that, in the shallow cylinder case, the azimuthal velocity follows the force radial distribution. The resulting velocity maximum occurs near the radial midpoint, unlike in the traditional rotating magnetic field (RMF) stirrer systems, where the velocity maximum occurs near the outer radius. An analytical description is developed to explain the velocity radial distribution. The numerically calculated velocity distribution shows a peculiar result that the bottom-stirred liquid metal container results in peak angular momentum at the top of the container. The solution to asymptotic boundary layer equations shows that this is due to the force axial variation.

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Hydrogen dissolves in molten aluminum and it is essential to reduce hydrogen concentration before making aluminum product. We propose a novel contactless degassing method that uses electromagnetic forces to drive the melt flow and split the injected inert gas bubbles. A numerical and experimental model of the proposed system were studied with a focus on characterizing permanent magnet-driven flows. For solving the multiphysics problem numerically, we coupled OpenFoam for hydrodynamic calculations and Elmer for electromagnetic calculations. The velocity field and developed pressure in a laboratory-scale physical model built using GaInSn in different operating regimes were examined and compared with the numerical model predictions. To characterize the conditions for bubble collapse, velocity pulsations were measured, and turbulence generation rate was computed. The results verify the feasibility of scaling the proposed degassing system. By implementing this gas purging method, the need of a rotating impeller and its associated problems would be eliminated.

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