Prediction of permeability and tortuosity in heterogeneous porous media using a disorder parameter

This paper investigates the effect of pore-space heterogeneity on fluid transport properties. To numerically describe the heterogeneity of pore structures, a disorder parameter is used, which is characterized by the variability in local porosity in the unit cells. The flow processes are investigated using lattice Boltzmann simulations in porous media with nearly isotropic porous structures consisting of particles of the same size and with different grain size distributions. It was found that increasing disorder positively affects tortuosity, which in turn causes a decrease in permeability. With increasing porosity, the sensitivity of the transport properties to changes in the disorder reduces. Based on approximations of numerical results, analytical equations were derived that predict permeability and tortuosity depending on porosity, disorder, and grain size distribution. Verification shows that the deviations between numerical and analytical results do not exceed 10%.