Development and validation of a multi-physics openfoam-based modelling tool set for liquid metal technologies in fission and fusion reactors

Liquid metals such as lead, lead-bismuth, and lead-lithium are attractive as coolants and tritium-breeding materials in fission and fusion reactors. Their high electrical conductivity, however, produces magnetohydrodynamic (MHD) effects in strong magnetic fields. These effects alter mass, momentum, and heat transport, creating steep boundary-layer gradients, larger pressure drops, and suppressed turbulence, so they require specialized computational fluid dynamics (CFD) approaches. The group’s OpenFOAM-based toolset began with a custom icoFoam solver and evolved into a conjugate heat and electrical multi-region solver for magneto-convective regimes. This framework has been validated for single-phase hydraulic, thermal-hydraulic, mixed, and natural convection cases. The work also extends to high-density-ratio two-phase flows. A custom interIsoFoam solver simulates bubble buoyancy in liquid metals under MHD conditions, and the authors model MHD capillary flow in porous media. For safety analyses of incidental scenarios, the authors use compressibleInterFoam to study pressure wave propagation in single- and two-phase liquid metal-gas mixtures. The solver has been validated against analytical solutions both without and with a magnetic field. Finally, they simulate the interaction between a subcooled high-pressure water jet and high-temperature lead-bismuth using icoReactingMultiphaseInterFoam, with validation against experimental data. The authors conclude that future work will strengthen the coupling between electromagnetic and multiphase solvers and add phase change and bubble nucleation in liquid metals. The aim is to provide the community with robust, validated tools for liquid metal technology.