Parametric study of liquid metal flows in conducting rectangular ducts in a strong nonuniform magnetic field
Parametric study of liquid metal flow in a conducting rectangular duct in a strong, decreasing magnetic field has been performed. Parameters such as the wall conductance ratio, c, the field gradient, γ, and the aspect ratios of the duct have been varied in the fusion-relevant range. Pressure drop correlations have been obtained for all the cases studied. If the duct is square, the correlation is very similar to the one for a circular duct. Many flow characteristics are similar as well. For a rectangular duct with long sides transverse to the field, three-dimensional (3D) effects are strong. There are very intensive trapped vortices in the nonuniform field region. The 3D pressure drop increases sharply with the increase of the aspect ratio. For a duct with long walls being parallel to the magnetic field, the 3D pressure drop tends to a constant, which depends on c and γ, when the aspect ratio becomes high. The velocity in most of the duct in the nonuniform field region becomes close to zero, and most of the mass flux is carried by the jets at the walls parallel to the magnetic field.