Digital storage 1 Discharge 1 Finite volume method 1 Flow of fluids 1 Heat characteristics Heat storage 1 Heat transfer 1 Melting 1 Melting time 1 Numerical methods 1 Phase change material 1 Phase change materials 1 Phase interfaces 1 Porosity 1 Porous materials 1 Porous medium 1 Shell-and-tube 1 Shell-tube system 1 Storage (materials) 1 Thermal storage 1 Tube systems 1 Tube-type 1 Type systems 1