digitation visqueuse

CONT: Forme de géométrie très irrégulière relevant d'une description fractale, présentant des protubérances digitiformes et qui illustre les phénomènes de percolation par invasion tels l'injection de pétrole dans un milieu poreux, le moulage métallique ou le stockage du gaz sous pression dans un sous-sol préalablement imbibé d'eau.

CONT: A related problem is viscous fingering, observed most conveniently at the interface of two liquids between two glass plates. For two miscible liquids, like gelatin and water, a DLA- like structure appears when one liquid invades the other .... This growth process is the result of a hydrodynamic instability between the liquids. As in DLA, any small ""bump"" on the interface will tend to grow predominantly at the tips because the pressure gradient, which drives the growth, is largest at the tips.