Fluid flow simulation in random porous media at pore level using Lattice Boltzmann Method

Fluid flow in two dimensional random porous media is simulated at pore level using the Lattice Boltzmann Method. Random media are constructed by placing identical rectangles with a random distribution and free overlapping. Different domain resolutions are examined and it is shown that the effect of the domain resolution is negligible in the range examined. Simulations clearly indicate, for the same porosity, the permeability of the random porous media is lower than the permeability of the regularly ordered medium, the permeability, independently of the porous media organization, varies exponentially with the porosity. Average tortuosity of the flow is calculated and it is proposed its correlation with the porosity using a third order polynomial. Tthe effect of the aspect ratio of the randomly placed obstacles on the predicted tortuosity and permeability is studied, and it is found that an increase of the obstacles' aspect ratio (height to width ratio) yields an increase of the tortuosity and consequent decrease of the permeability. The predicted values of the permeability and tortuosity are in close agreement with the data available in the literature.