Anomalous interface roughening in porous media: experiment and model
We report measurements of the interface formed when a wet front propogates in paper by imbibition and we find anomalous roughening with exponent α=0.63±0.04. We also formulate an imbibition model that agrees with the experimental morphology. The main ingredient of the model is the propogation and pinning of a self-affine interface in the presence of quenched disorder, with erosion of overhangs. By relating our model to directed percolation, we find α~0.63.
S.V. Buldyrev, A.-L. Barabási, F. Caserta, S. Havlin, H.E. Stanley, T. Vicsek