During melting or solidification, the solid and liquid phases interact across a moving interface. This interface can be resolved either implicitly, using a one-fluid approach, or explicitly, with a partitioned approach. One-fluid methods, such as the enthalpy-porosity method [1], solve a single set of equations for both solid and liquid phases on a fixed mesh, making them straightforward to implement. This means, however, that a momentum source term is required to bring the fluid velocity to zero when it solidifies. This source term includes a fitting parameter without physical meaning, namely the mushy zone constant in case of the enthalpy-porosity method, which limits the predicting capability of the method [2]. Partitioned approaches, on the other hand, model the solid and liquid zones separately, applying the appropriate physical laws for each zone. Interaction between the phases is achieved by enforcing the Stefan condition at the coupling interface [3]. As such, no unphysical fitting parameter is needed, but the moving boundary in both the solid and liquid domains necessitates mesh adaptation at each time step. Particularly in regions of rapid phase change, where cells experience significant stretching, grid distortion is likely to occur. To address the challenges posed by the moving mesh, smoothing, layering, and remeshing methods are explored. Additional complexities arise during constrained melting, where the solid remains attached to parts of the domain boundaries. This creates an end point of the solid-liquid interface moving along the domain boundaries. To ensure it stays on the domain boundary during interface motion, a node projection technique is developed and tested. Furthermore, a procedure is established for cases where the end points transition between different domain boundaries. REFERENCES [1] V. R. Voller and C. Prakash, “A fixed grid numerical modelling methodology for convection-diffusion mushy region phase-change problems,” Int J Heat Mass Transf, vol. 30, no. 8, pp. 1709–1719, (1987). [2] T. Shockner et al., “Simultaneous close-contact melting on two asymmetric surfaces: Demonstration, modeling and application to thermal storage,” Int J Heat Mass Transf, vol. 232, p. 125950, (2024). [3] M. Lacroix and V. R. Voller, “Finite difference solutions of solidification phase change problems: Transformed versus fixed grids,” Numerical Heat Transfer, Part B: Fundamentals, vol. 17, no. 1, pp. 25–41, (1990).