Determining the impact of rectangular grain aspect ratio on tortuosity-porosity correlations of two-dimensional stochastically generated porous media

Tortuosity is an important parameter for characterizing transport properties within porous materials and is of interest in a broad range of fields, such as energy storage and conversion materials. One of the parameters that impacts the tortuosity value is the geometry of the solid phase which, in this study, is considered as stochastically-placed rectangular particles. Through lattice Boltzmann modelling (LBM), we determined the impact of particle aspect ratio on the intrinsic tortuosity-porosity relationships of two-dimensional porous media composed of rectangular particles. These relationships were isolated for materials with grain (particle) aspect ratios of is an element of {1, 2, 3} and porosities from [0.55 - 0.95]. We determined that a minimum of 6, 8 and 10 stochastic simulations, respectively, were required to calculate these average tortuosity values in laminar flow (Re << 1). This novel application of the LBM to study the effects of porosity and aspect ratio of rectangular grains on tortuosity can be used in the tailoring of materials for clean energy.