Liquid metal flow subject to a uniform magnetic field vertical to streamwise direction confined in a rectangular duct with 45° and 90° sudden expansion, and electrically conducting walls is numerically studied using magnetohydrodynamic (MHD) flow solver developed in OpenFOAM environment. Velocity distribution, induced electric current, pressure gradient and three-dimensional MHD effect are analyzed in detail. It shows that as external magnetic field is parallel to direction of duct expansion, velocity distribution is better in 45° sudden expansion duct than that in 90° expansion duct since there is no vortex at the expansion. With Hartmann number increasing, high velocity jets and intensive induced electric current cause a strong instability at the expansion. Instability grows to upstream of the expansion through induced electric current. As external magnetic field is vertical to expansion direction, induced electric current along streamwise direction is significant. With Hartmann number increasing, MHD pressure drop increases remarkably. Dimensionless pressure drop in fully developed duct is almost the same in different expansion duct as direction of applied magnetic field and Hartmann number are the same.

Mangetohydrodynamic flow in a rectangular duct with flow channel insert and pressure equalization slot for fusion liquid metal blanket is studied numerically with a two-dimensional fully developed flow model.Velocity field and MHD pressure drop varying with Hartmann number and electric conductivity of FCI is analyzed.Compared with normal duct flow,MHD pressure drop with insulating FCI is reduced significantly.Dimensionless MHD pressure drop decreases as Hartmann number grows.Furthermore,reduction of MHD pressure drop becomes weaker as FCI electric conductivity increases.Reverse flow at pressure slot is related to electric conductivity of FCI.Numerical results are in good agreement with experimental and simplified results.