title: Particle pressure in a sheared suspension: a bridge from osmosis to granular dilatancy.
abstract: The normal stress exerted by particles in a sheared suspension is measured by analogy with a method used to measure osmotic pressure in solutions. Particles in a liquid are confined by a fine screen to a gap between two vertical concentric cylinders, the inner of which rotates. Pressure in the liquid is sensed either by a manometer or by a pressure transducer across the screen. The particles are large enough so that Brownian motion and equilibrium osmotic pressure are vanishingly small. The measured pressure yields the shear-induced particle pressure Pi, the nonequilibrium continuation of equilibrium osmotic pressure. For volume fractions 0.3< or =varphi< or =0.5, Pi is strongly dependent on varphi, and linear in shear rate. Comparisons of the measured particle pressure with modeling and simulation show good agreement.
authors.affiliation: Univ Pierre et Marie Curie-Paris6, Univ Paris-Sud, CNRS, Laboratoire FAST, Campus universitaire d'Orsay, 91405 Orsay Cedex, France.
authors.forename: Angélique
authors.initials: A
authors.lastname: Deboeuf
authors.forename: Georges
authors.initials: G
authors.lastname: Gauthier
authors.forename: Jérôme
authors.initials: J
authors.lastname: Martin
authors.forename: Yevgeny
authors.initials: Y
authors.lastname: Yurkovetsky
authors.forename: Jeffrey F
authors.initials: JF
authors.lastname: Morris