Laboratoire Matière et Systèmes Complexes

MSC, permanents : S. Lerouge, G. Grégoire, O. Cardoso, C. Gay, M.A. Guedeau-Boudeville.

Collaborations : S. Manneville (ENS Lyon), G.H. McKinley (MIT), A. Colin (LOF Bordeaux), A. Morozov (Edinburgh), L. Pauchard (FAST Orsay), O. Radulescu (Montpellier), M. Argentina (Nice).

Thèses :

• Benoît Lasne. Écoulement tridimensionnel de micelles géantes (soutenue le 22/09/2010).
• Marc-Antoine Fardin. From shear-banding to elastic turbulence, a study in rheology (soutenance le 09/07/2012). Page personnelle de Marc-Antoine Fardin.

The flow of a Newtonian fluid is governed by a dimensionless number, the Reynolds number Re that compares inertial and viscous effects. At low Re, the flow is laminar and stable. For intermediate Re, the flow becomes unstable and coherent structures leading to various patterns develop. Finally, at high Reynolds number, the flow becomes turbulent. In the case of viscoelastic polymers or micelles solutions, the Reynolds number is negligible due to the large viscosity of the solutions. The dimensionless number governing the flow is the Weissenberg number Wi that compares elastic and viscous forces. Viscoelastic flows follow, as a function of Wi, a scenario very similar to Newtonian flows described above. In our team, we characterize this sequence of transitions towards viscoelastic 3D flows (coherent or turbulent) in different flow geometries. We also study the effects of the boundary conditions on the thresholds and on the flow patterns.

[9] Interplay between elastic instabilities and shear-banding: Three categories of Taylor-Couette flows and beyond M.A. Fardin, T.J. Ober, V. Grenard, T. Divoux, S. Manneville, G.H. McKinley, S. Lerouge. soumis à Soft Matter, 2012.

[8] Instabilities in giant micelles: from shear-banding to elastic turbulence M. A. Fardin and S. Lerouge. Colloquium soumis à Eur. Phys. J. E, 2012.

[7] Shear-banding in surfactant wormlike micelles: Elastic instabilities and wall slip M.A. Fardin, T. Divoux, M.A. Guedeau-Boudeville, I. Buchet-Maulien, J. Browaeys, G.H. McKinley, S. Manneville, S. Lerouge. Soft Matter, 8, 2535-2553 , 2012.

[6] Potential “ways of thinking” about the shear banding phenomenon M.A. Fardin, T.J. Ober, C. Gay, G. Gr\’egoire, G.H. McKinley, S. Lerouge. Soft Matter, 8, 910-922 , 2012.

[5] Criterion for purely elastic Taylor-Couette instability in the flows of shear-banding fluids M. A. Fardin, T.J. Ober, C. Gay, G. Gr\’egoire, G. H. McKinley and S. Lerouge. Eur. Phys. Lett., 96, 44004, 2011.

[4] Elastic turbulence in shear banding wormlike micelles M.F. Fardin, D. Lopez, J. Croso, O. Cardoso, G. Grégoire, G.H. McKinley, S. Lerouge. Phys. Rev. Lett.,104 : 178303 , 2010.

[3] Shear-Induced Transitions and Instabilities in Surfactant Wormlike Micelles S. Lerouge, J.F. Berret. Advances in Polymer Science, 230, 1-71, 2010.

[2] Taylor-like vortices in shear banding flow of giant micelles M.F. Fardin, B. Lasne, O. Cardoso, G. Grégoire, M. Argentina, J.P. Decruppe, S. Lerouge. Phys.\ Rev.\ Lett., 103 : 028302, 2009.

[1] Interface dynamics in shear banding flow of giant micelles S. Lerouge, M.F. Fardin, M. Argentina, G. Grégoire, O. Cardoso. Soft Matter, 4 : 1808, 2008.