title: Run-and-tumble particles with hydrodynamics: sedimentation, trapping, and upstream swimming.
abstract: We simulate by lattice Boltzmann the nonequilibrium steady states of run-and-tumble particles (inspired by a minimal model of bacteria), interacting by far-field hydrodynamics, subject to confinement. Under gravity, hydrodynamic interactions barely perturb the steady state found without them, but for particles in a harmonic trap such a state is quite changed if the run length is larger than the confinement length: a self-assembled pump is formed. Particles likewise confined in a narrow channel show a generic upstream flux in Poiseuille flow: chiral swimming is not required.
authors.affiliation: SUPA, School of Physics, University of Edinburgh, JCMB Kings Buildings, Edinburgh EH9 3JZ, United Kingdom.
authors.forename: R W
authors.initials: RW
authors.lastname: Nash
authors.forename: R
authors.initials: R
authors.lastname: Adhikari
authors.forename: J
authors.initials: J
authors.lastname: Tailleur
authors.forename: M E
authors.initials: ME
authors.lastname: Cates
mesh_terms: D001419:Bacteria / Q000166:cytology*; D018407:Bacterial Physiological Phenomena; D006112:Gravitation; D057446:Hydrodynamics; D008954:Models, Biological; D013550:Swimming