Open-cell metal foams are widely recognized for their high specific surface area and interconnected porous architecture, enabling enhanced heat and mass transfer in compact energy systems. To elucidate the coupled transport behavior at the pore scale, a series of three-dimensional lattice Boltzmann simulations were performed, explicitly resolving foam skeleton geometries with varying pores per inch (PPI), ligament thicknesses, and unit cell rotation angles.
Results show that increasing the PPI—corresponding to smaller pore sizes and denser structures—significantly decreases both the effective diffusivity and permeability due to narrower and more tortuous flow channels, while enhancing thermal conduction and thus reducing thermal resistance. Thicker ligaments further suppress mass transport by lowering porosity but improve heat transfer by increasing the conductive cross-section. Moreover, rotating the foam units induces periodic variations in both mass and heat transport performance, without markedly altering porosity. The anisotropic response originates from the reconfiguration of flow and thermal pathways, where certain orientations promote straighter, more continuous channels, while others increase tortuosity and resistance.
A combined analysis of PPI and rotation effects on thermal resistance reveals that PPI is the dominant factor, whereas orientation offers a secondary tuning parameter for performance optimization. These findings quantitatively establish the structure–property relationships of metal foams, providing design guidelines for advanced applications such as fuel cell gas diffusion layers, chemical reactor packings, and high-performance heat exchangers.
Open-cell metal foams are widely recognized for their high specific surface area and interconnected porous architecture, enabling enhanced heat and mass transfer in compact energy systems. To elucidate the coupled transport behavior at the pore scale, a series of three-dimensional lattice Boltzmann simulations were performed, explicitly resolving foam skeleton geometries with varying pores per inch (PPI), ligament thicknesses, and unit cell rotation angles.
Results show that increasing the PPI—corresponding to smaller pore sizes and denser structures—significantly decreases both the effective diffusivity and permeability due to narrower and more tortuous flow channels, while enhancing thermal conduction and thus reducing thermal resistance. Thicker ligaments further suppress mass transport by lowering porosity but improve heat transfer by increasing the conductive cross-section. Moreover, rotating the foam units induces periodic variations in both mass and heat transport performance, without markedly altering porosity. The anisotropic response originates from the reconfiguration of flow and thermal pathways, where certain orientations promote straighter, more continuous channels, while others increase tortuosity and resistance.
A combined analysis of PPI and rotation effects on thermal resistance reveals that PPI is the dominant factor, whereas orientation offers a secondary tuning parameter for performance optimization. These findings quantitatively establish the structure–property relationships of metal foams, providing design guidelines for advanced applications such as fuel cell gas diffusion layers, chemical reactor packings, and high-performance heat exchangers.

Metal foam, Pore-scale simulation, Lattice Boltzmann method, Heat and mass transfer, Structural parameters