EFFECTIVE GAS DIFFUSION COEFFICIENT OF FRACTAL POROUS MEDIA WITH ROUGH SURFACES BY MONTE CARLO SIMULATIONS

Gas diffusion coefficient is an important parameter in characterizing gas transport in porous media. Based on the fractal characteristics of microscopic capillaries, the effect of capillary surface roughness on gas diffusion is considered by the Monte Carlo technique. We proposed a probability model of the effective gas diffusion coefficient of the porous media with rough surfaces. This model is expressed as a function of the geometrical parameters of porous media, such as the porosity, the pore fractal dimension, the tortuosity fractal dimension, and the relative roughness. The simulated effective gas diffusion coefficient is compared with the available experimental data and a good agreement between them is obtained. The effect of the structural parameters of porous media on gas diffusion is analyzed in detail.