EFFECTIVE DIFFUSION-COEFFICIENT - FROM HOMOGENIZATION TO EXPERIMENT

In this paper, an example of the application of the homogenization app roach (asymptotic expansion technique) to predict the effective diffus ion coefficient for an equivalent continuum, together with the experim ental verification of the theoretical results is presented. The experi mental setup was constructed for the measurements of diffusion in a mo del periodic porous medium made of Plexiglas. The computer program usi ng the FEM was elaborated to solve the local boundary value problem fo r a period and to calculate the effective diffusion coefficient. The c omparison between the theory and the experiment indicates good agreeme nt between the numerical and experimental values of the effective diff usion coefficient. Interpretation of the test data from the point of v iew of the homogenization theory is also incorporated.