Modeling the free-surface magnetohydrodynamics of thick liquid metal walls for fusion

Abstract: Renaissance Fusion proposes thick liquid metal walls as plasma-facing components for future commercial fusion reactors. It designs and operates proof-of-concept experiments aiming at actively suspending and stabilizing a flowing free-surface liquid metal layer against gravity using Lorentz forces. The first operating prototype consists of a 1 m-diameter chamber in the presence of a magnetic field of the order of 0.3 T. A GaInSn flow is injected inside the chamber, and it is actively suspended thanks to the injection of currents up to 3 kA. To simulate the prototype, a numerical tool capable of modeling magnetohydrodynamics phenomena in two-phase flows has been developed to reproduce and interpret the experimental results. The tool relies on the low-magnetic Reynolds assumption, implements the Volume-of-Fluid method for tracking the free-surface, and couples the electric potential in both fluid and solid domains.