title: Red blood cells and other nonspherical capsules in shear flow: oscillatory dynamics and the tank-treading-to-tumbling transition.
abstract: We consider the motion of red blood cells and other nonspherical microcapsules dilutely suspended in a simple shear flow. Our analysis indicates that depending on the viscosity, membrane elasticity, geometry, and shear rate, the particle exhibits either tumbling, tank-treading of the membrane about the viscous interior with periodic oscillations of the orientation angle, or intermittent behavior in which the two modes occur alternately. For red blood cells, we compute the complete phase diagram and identify a novel tank-treading-to-tumbling transition as the shear rate decreases. Observations of such motions coupled with our theoretical framework may provide a sensitive means of assessing capsule properties.
authors.affiliation: Center for Studies in Physics and Biology, The Rockefeller University, New York, New York 10021, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Skotheim
authors.forename: T W
authors.initials: TW
authors.lastname: Secomb
mesh_terms: D000465:Algorithms; D001696:Biomechanical Phenomena; D002214:Capsules; D004548:Elasticity; D004910:Erythrocyte Membrane / Q000502:physiology; D004912:Erythrocytes / Q000502:physiology*; D033081:Shear Strength; D013535:Suspensions; D014783:Viscosity
chemical_list: D002214:Capsules; D013535:Suspensions