Computational experiments on three-dimensional molecular diffusion in porous media

摘要

Estimations of apparent diffusion coefficients usually consist of curve-fitting the output of 1-D models to experimental laboratory-measured data from porous aggregates shaped in different forms. In this research, a computational exploration is presented on the alternative use of three-dimensional models for the same purpose. The outputs of the 3-D models were compared to results generated by one-dimensional formulations. The comparison showed that there are significant discrepancies in the concentration values output by the models. Percent differences ranging from 30 to 90% were calculated. Those different estimations suggest that different values of the apparent diffusion coefficient may be obtained if the three-dimensional solution of the diffusion equation would be used to match experimental results.