Initial liquid metal magnetohydrodynamic thin film flow experiments in the McGA-loop facility at UCLA

Free surface, thin film flows of liquid metal were investigated experimentally in the presence of a coplanar magnetic field. This investigation was performed in a new magnetohydrodynamic (MHD) flow facility, the McGA-loop, utilizing a low melting temperature lead-bismuth alloy as the working metal. Owing to the relatively low magnetic field produced by the present field coil system, the ordinary hydrodynamic and low MHD interaction regimes only were investigated. At the high flow speeds necessary for self cooling, the importance of a well designed and constructed channel becomes obvious. MHD drag, increasing the film height, is observed as Haβ2 becomes greater than unity. Partial MHD laminarization of the turbulent film flows is observed when Haβ/Re > 0.002, but fully laminar flow was not reached. Suggestions for facility upgrades to achieve greater MHD interaction are presented in the context of these initial results.