Ultrasound velocimetry in a shear-thickening wormlike micellar solution: Evidence for the coexistence of radial and vorticity shear bands

Abstract : We carried out pointwise local velocity measurements on 40mM cetylpyridinium chloride-sodium salicylate (CPyCl-NaSal) wormlike micellar solution using high-frequency ultrasound velocimetry in a Couette shear cell. The studied wormlike solution exhibits Newtonian, shear-thinning and shear-thickening rheological behavior in a stress-controlled environment. Previous rheology, flow visualization and small-angle light/neutron scattering experiments in the shear-thickening regime of this system showed the presence of stress-driven alternating transparent and turbid rings or vorticity bands along the axis of the Couette geometry. Through local velocity measurements we observe a homogeneous flow inside the 1mm gap of the Couette cell in the shear-thinning (stress-plateau) region. Only when the solution is sheared beyond the critical shear stress (shear-thickening regime) in a stress-controlled experiment, we observe inhomogeneous flow characterized by radial or velocity gradient shear bands with a highly sheared band near the rotor and a weakly sheared band near the stator of the Couette geometry. Furthermore, fast measurements performed in the shear-thickening regime to capture the temporal evolution of local velocities indicate coexistence of both radial and vorticity shear bands. However the same measurements carried out in shear rate controlled mode of the rheometer do not show such rheological complexity.
Type de document :
Article dans une revue
European Physical Journal E: Soft matter and biological physics, EDP Sciences: EPJ, 2008, 26 (1-2), pp.3-12. 〈10.1140/epje/i2007-10304-3〉
Liste complète des métadonnées

Littérature citée [43 références]  Voir  Masquer  Télécharger

https://hal-ens-lyon.archives-ouvertes.fr/ensl-00526262
Contributeur : Sébastien Manneville <>
Soumis le : jeudi 14 octobre 2010 - 10:29:22
Dernière modification le : jeudi 19 avril 2018 - 14:54:03
Document(s) archivé(s) le : samedi 15 janvier 2011 - 02:39:29

Fichier

Herle_EPJE_soumis.pdf
Fichiers produits par l'(les) auteur(s)

Identifiants

Collections

Citation

Vishweshwara Herle, Sébastien Manneville, Peter Fischer. Ultrasound velocimetry in a shear-thickening wormlike micellar solution: Evidence for the coexistence of radial and vorticity shear bands. European Physical Journal E: Soft matter and biological physics, EDP Sciences: EPJ, 2008, 26 (1-2), pp.3-12. 〈10.1140/epje/i2007-10304-3〉. 〈ensl-00526262〉

Partager

Métriques

Consultations de la notice

84

Téléchargements de fichiers

124