A novel architecture for pore network modelling with applications to permeability of porous media

Network models of porous media are beneficial for predicting the evolution of macroscopic mass transport properties. This work proposes a novel bi-regular network model based on truncated octahedral support. With the model, pore systems with different pore coordination spectra for a given average coordination number can be constructed to match experimental data. This feature and the maximum allowed pore coordination of 14 make the proposed model more realistic and flexible than the existing models based on cubic supports. Limestone is used as a study material to illustrate the model performance. Experimental pore space data for this material obtained by X-ray tomography (CT) are used for constructing microstructure-informed model realisations. It is demonstrated that with these realisations the experimentally measured permeability of the material can be predicted. The model is further used to assess the effects of pore connectivity and porosity on the permeability. It is shown that the effect of pore connectivity is substantially stronger than the effect of porosity. A strategy for calculating the evolution of permeability with damage-related pore space changes is also described. The results reveal the effects of the mechanical properties of the medium on the permeability evolution as a function of damage evolution. Developments of this strategy are suggested for deriving mechanism-based constitutive laws for engineering applications.