title: Influence of the elastic deformation of a foam on its mobility in channels of linearly varying width.
abstract: We study foam flow in an elementary model porous medium consisting of a convergent and a divergent channel positioned side by side and possessing a fixed joint porosity. Configurations of converging or diverging channels are ubiquitous at the pore scale in porous media, as all channels linking pores possess a converging and diverging part. The resulting flow kinematics imposes asymmetric bubble deformations in the two channels, which modulate foam-wall friction and strongly impact the flux distribution. We measure, as well as quantitatively predict, the ratio of the fluxes in the two channels as a function of the channel widths by modeling pressure drops of both viscous and capillary origins. This study reveals the crucial importance of boundary-induced bubble deformation on the mobility of a flowing foam, resulting in particular in flow irreversibility.
authors.affiliation: Institut de Physique de Rennes, Université Rennes 1, CNRS UMR No. 6251, Campus Beaulieu, 35042 Rennes Cedex, France.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Dollet
authors.affiliation: Institut de Physique de Rennes, Université Rennes 1, CNRS UMR No. 6251, Campus Beaulieu, 35042 Rennes Cedex, France.
authors.forename: Siân A
authors.initials: SA
authors.lastname: Jones
authors.affiliation: Géosciences, Université Rennes 1, CNRS UMR No. 6118, Campus Beaulieu, 35042 Rennes Cedex, France.
authors.forename: Yves
authors.initials: Y
authors.lastname: Méheust
authors.affiliation: Institut de Physique de Rennes, Université Rennes 1, CNRS UMR No. 6251, Campus Beaulieu, 35042 Rennes Cedex, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Cantat
mesh_terms: D004548:Elasticity; D016014:Linear Models; D008962:Models, Theoretical; D009038:Motion; D016062:Porosity; D011312:Pressure; D014783:Viscosity