title: Disorder-induced capillary bursts control intermittency in slow imbibition.
abstract: A multiscale analysis of the spatially averaged velocity of an imbibition front V_{ℓ}(t) measured at scale ℓ reveals that the slow front dynamics is intermittent: the distributions of ΔV_{ℓ}(τ)=V_{ℓ}(t+τ)-V_{ℓ}(t) evolve continuously through time scales τ, from heavy-tailed to Gaussian-reached at a time lag τ_{c} set by the extent of the medium heterogeneities. Intermittency results from capillary bursts triggered from the smallest scale of the disorder up to the scale ℓ_{c} at which viscous dissipation becomes dominant. The effective number of degrees of freedom of the front ℓ/ℓ_{c} controls its intensity.
authors.affiliation: Departament ECM, Facultat de Física, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Catalonia, Spain and Laboratoire de Physique, CNRS UMR 5672, École Normale Supérieure de Lyon, 46 Allée d'Italie, 69364 Lyon Cedex 07, France.
authors.forename: Xavier
authors.initials: X
authors.lastname: Clotet
authors.affiliation: Departament ECM, Facultat de Física, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Catalonia, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Ortín
authors.affiliation: Laboratoire de Physique, CNRS UMR 5672, École Normale Supérieure de Lyon, 46 Allée d'Italie, 69364 Lyon Cedex 07, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Santucci