Saffman-Taylor fingering: why it is not a proper upscaled model of viscous fingering in a (even two-dimensional) random porous medium

Yves Meheust1, Renaud Toussaint2, Grunde Lovoll3 and Knut Jorgen Maloy3, (1)University of Rennes, Geosciences, CNRS, UMR 6118, Rennes Cedex, France, (2)ITES, University of Strasbourg CNRS, Strasbourg, France, (3)University of Oslo, Physics Department, Oslo, Norway