Numerical study of mhd thin-film flows for plasma facing components

A liquid metal film offers unique properties to withstand the large thermal load on a Plasma-Facing Components (PFCs) in a nuclear reactor but the interaction between this conductive fluid and the tokamak magnetic fields leads to Magnetohydrodynamic (MHD) phenomena that influence the flow features. To properly design the PFCs is necessary to accurately predict these features and heat transfer for free surface MHD flow. In the first part of this work, the general purpose CFD code ANSYS CFX 18.2 is validated for MHD thin film flow with isolated walls, up to a Hartmann Number and for several values of the characteristic width/thickness ratio, comparing the results with the analytical relation developed by Shishko. For all the cases considered, the maximum integral error is found below . In the second part, a chute with characteristic film ratio equal to and for is investigated to describe the flow for the case of uniform and non-uniform wall electrical conductivity. The electrical conductivity of the back plate is found to have a negligible effect on the global flow, similarly to what is observed for the analogue bounded flow. Contrariwise, an electrically conducting lateral wall is found to enhance the free surface jet and to modify the Hartmann layer structure.