title: Analytical analysis of a vesicle tumbling under a shear flow.
abstract: Vesicles under a shear flow exhibit a tank-treading motion of their membrane, while their long axis points with an angle <pi/4 with respect to the shear stress if the viscosity contrast between the interior and the exterior is not large enough. Above a certain viscosity contrast, the vesicle undergoes a tumbling bifurcation, a bifurcation which is known for red blood cells. We have recently presented the full numerical analysis of this transition. In this paper, we introduce an analytical model that has the advantage of being both simple enough and capturing the essential features found numerically. The model is based on general considerations and does not resort to the explicit computation of the full hydrodynamic field inside and outside the vesicle.
authors.affiliation: Groupe de Recherche sur les Phénomènes Hors Equilibres, LSP, Université Joseph Fourier, CNRS (UMR 5588), Boîte Postale 87, F-38402 Saint Martin d'Hères cedex, France.
authors.forename: F
authors.initials: F
authors.lastname: Rioual
authors.forename: T
authors.initials: T
authors.lastname: Biben
authors.forename: C
authors.initials: C
authors.lastname: Misbah
mesh_terms: D003198:Computer Simulation; D008081:Liposomes; D008560:Membrane Fluidity; D044085:Microfluidics / Q000379:methods*; D008962:Models, Theoretical; D009038:Motion; D010316:Particle Size; D012399:Rotation; D033081:Shear Strength; D013314:Stress, Mechanical; D014783:Viscosity
chemical_list: D008081:Liposomes