title: Flow-induced structures versus flow instabilities.
abstract: The Taylor-Couette flow of a dilute micellar system known to generate shear-induced structures is investigated through simultaneous rheometry and ultrasonic imaging. We show that flow instabilities must be taken into account since both Reynolds and Weissenberg numbers may be large. Before nucleation of shear-induced structures, the flow can be inertially unstable, but once shear-induced structures are nucleated, the kinematics of the flow become chaotic, in a pattern reminiscent of the elastically dominated turbulence known in dilute polymer solutions. We outline a general framework for the interplay between flow instabilities and flow-induced structures.
authors.affiliation: Université de Lyon, Laboratoire de Physique, École Normale Supérieure de Lyon, CNRS UMR 5672, 46 Allée d'Italie, 69364 Lyon cedex 07, France and The Academy of Bradylogists, Paris, France.
authors.forename: M A
authors.initials: MA
authors.lastname: Fardin
authors.affiliation: Université de Lyon, Laboratoire de Physique, École Normale Supérieure de Lyon, CNRS UMR 5672, 46 Allée d'Italie, 69364 Lyon cedex 07, France.
authors.forename: C
authors.initials: C
authors.lastname: Perge
authors.affiliation: Université de Lyon, Laboratoire de Physique, École Normale Supérieure de Lyon, CNRS UMR 5672, 46 Allée d'Italie, 69364 Lyon cedex 07, France.
authors.forename: N
authors.initials: N
authors.lastname: Taberlet
authors.affiliation: Université de Lyon, Laboratoire de Physique, École Normale Supérieure de Lyon, CNRS UMR 5672, 46 Allée d'Italie, 69364 Lyon cedex 07, France.
authors.forename: S
authors.initials: S
authors.lastname: Manneville