Abstract
•Two simulation approaches were adopted for melting of PCM in finned metal foam.•Local thermal equilibrium between metal foam and phase change material was justified.•The one-equation model sufficed to model the paraffin-saturated metal foam.•The melting process was expedited by natural convection of liquid PCM in metal foam.•The finned metal foam outperformed the conventional plate-fin for latent heat storage.
The melting process of phase change material (PCM) infiltrated in a finned metal foam was numerically investigated using two approaches: (a) pore-scale and (b) volume-averaged numerical simulations. The pore-scale simulation modeled the intricate geometry of the open-cell metal foam using sphere-centered tetrakaidecahedron and coupled the heat transfer in foam/fin solids with that in the PCM. The volume-averaged simulation used the Darcy–Brinkman–Forchheimer model to account for the motion of melt PCM as well as the one-temperature model based on local thermal equilibrium assumption. The volume-averaged simulation results were compared with the pore-scale simulation results which were used as the benchmark. Reasonable agreement between prediction results of the two approaches was observed. When using the volume-averaged method, the one-temperature model may be applicable without needing the more complicated two-temperature model. The thermal performance of the finned metal foam was compared with conventional plate-fin and metal foam structures, demonstrating its superiority as thermal conductivity enhancer of PCM.