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

TL;DR

This paper develops a numerical model to simulate the magnetohydrodynamics of a flowing liquid metal surface in fusion reactor prototypes, aiding in the design of plasma-facing liquid metal walls.

Contribution

It introduces a new two-phase flow magnetohydrodynamics simulation tool incorporating the Volume-of-Fluid method and electric potential coupling for fusion applications.

Findings

Successful simulation of liquid metal suspension using the model

Insights into magnetic and flow interactions in fusion wall prototypes

Validation against experimental prototype data

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.