Constrained optimization Convergence of numerical methods Discontinous Galerkin methods Energy Energy-conservative discontinuous Galerkin method Energy-conservative discontinuous galerkin method Enthalpy Enthalpy approach FEM approaches Finite element method Galerkin methods Gallium Linearization Linearized enthalpy approach Melting Phase change problem Problem-based Second orders Solid liquid phase change linearized enthalpy approach solid–liquid phase change