title: Effective viscosity of dilute bacterial suspensions: a two-dimensional model.
abstract: Suspensions of self-propelled particles are studied in the framework of two-dimensional (2D) Stokesean hydrodynamics. A formula is obtained for the effective viscosity of such suspensions in the limit of small concentrations. This formula includes the two terms that are found in the 2D version of Einstein's classical result for passive suspensions. To this, the main result of the paper is added, an additional term due to self-propulsion which depends on the physical and geometric properties of the active suspension. This term explains the experimental observation of a decrease in effective viscosity in active suspensions.
authors.affiliation: Department of Mathematics, Pennsylvania State University, 418 McAllister Building, University Park, PA 16802, USA.
authors.forename: Brian M
authors.initials: BM
authors.lastname: Haines
authors.forename: Igor S
authors.initials: IS
authors.lastname: Aronson
authors.forename: Leonid
authors.initials: L
authors.lastname: Berlyand
authors.forename: Dmitry A
authors.initials: DA
authors.lastname: Karpeev
mesh_terms: D000465:Algorithms; D001412:Bacillus subtilis / Q000737:chemistry / Q000502:physiology; D003198:Computer Simulation; D004926:Escherichia coli / Q000737:chemistry / Q000502:physiology; D008962:Models, Theoretical; D012212:Rheology; D033081:Shear Strength; D012996:Solutions / Q000737:chemistry; D013535:Suspensions; D014783:Viscosity
chemical_list: D012996:Solutions; D013535:Suspensions