High-fidelity simulations of fluid-solid interactions during liquid metal casting processes

The preset work focuses on modeling of the initial stages of dross formation resulting from the interaction of the laminar/turbulent jet impinging on a free-surface. In the presence of air, a thin metal oxide layer forms on the surface of the liquid changing the dynamics of the jet as well as the resulting air-entrainement. The basis for the proposed formulation is our in-house, two-phase flow solver for incompressible flows, where we included the thin, highly deformable film that is formed on the liquid-gas interface. The frequent breakups of this oxidized layer render classical fluid-structure interaction methods where the solid is considered in a Lagrangian reference frame impractical. To address this issue we developed a fully Eulerian approach to model the liquid-gas-solid interactions. In particular, we use level set formulations to track both fluid-solid interfaces and the strain history of the deformable solid. The latter is accomplished by constructing a dynamic grid using three reference level set functions (one for each dimension) advected by the local velocity field. A unified framework is used to solve the equations governing the fluid and solid dynamics on the same fixed grid. Across the interface the shear modulus transitions smoothly from the bulk shear modulus to zero in a few computational cells.