Invasion Percolation in an Etched Network: Measurement of a Fractal Dimension

Abstract

A wetting fluid is displaced at very low flow rate by a nonwetting fluid in a 250 000-duct, transparent, etched network. The structure formed by the injected fluid is ramified and the scale invariance is described by a measured fractal dimension $1.80<D<\mathrm{}1.83\mathrm{}$. This value agrees with theoretical results of invasion percolation with trapping.