Macroscopic transport properties of Gyroid structures based on pore-scale studies: Permeability, diffusivity and thermal conductivity

Gyroid structure is a kind of triply periodic minimum surface, which presents several advantages such as free-standing, highly ordered and interconnected pore network and high specific surface area. Understanding transport processes inside the Gyroid structure is important for its application. In this study, porous structures of the Gyroid are reconstructed, and then pore-scale studies of fluid flow, diffusion and heat transfer in the two phases of Gyroid structures are numerically implemented using the lattice Boltzmann method (LBM). Pore-scale velocity, concentration and temperature fields inside the Gyroid structures are discussed, based on which macroscopic properties including permeability, effective diffusivity, effective thermal conductivity, and tortuosity are predicted. There are two phases in the Gyroid structures, and both phases are continuous, leading to the bicontinuous characteristic of Gyroid structures. The results show that transport resistance in one phase is lower than that in the other phase. Thus from the perspective of enhancing transport process, it is desirable to choose the phase with higher transport properties for transporting the slower process. The present study provides guidance for subsequent applications of Gyroid structure.