Magnetohydrodynamic flows in breeder units of a HCLL blanket with spatially varying magnetic fields

Liquid metal flows in two connected breeder units exposed to a spatially varying strong magnetic field are investigated theoretically by inertialess asymptotic analyses and numerical simulations. Since the asymptotic method, which applies best for small velocities, provides fast results, it is used for a parametric study of the influence of various field gradients on the flow distribution near the first wall. Full numerical simulations complement the analysis for cases where inertia forces are not negligible and for geometries whose details cannot be modelled adequately by the former method. A strong influence of the nonuniform magnetic field on the pressure drop exists near the first wall gap, while the effect on flow redistribution in side layers remains weak.