Section: New Results

Models for dispersion in porous media

Participants : Carole Delenne, Vincent Guinot.

Solute dispersion in porous media is usually modelled using Fick's law or fractional variations of the solute dispersion equation. The Fickian model, however, is known to exhibit a number of drawbacks, such as poor scaling properties. This is also true for its fractional counterparts, that perform with limited success when compared to experimental data sets. In [13] , a high-quality experimental device is built in the form of periodic heterogeneities of length 15 cm. Placing up to 10 periods in series allows the scaling properties of the dispersion model to be analyzed. Besides providing a high quality experimental database, the results in [13] indicate that (i) previously identified scaling trends for the dispersion coefficient may easily be explained by experiment variability, (ii) there exists a linear transport model that allows the experimental behaviour to be reproduces at all scales, (iii) this model is not the advection-dispersion model (even fractional).