title: Purely hydrodynamic origin for swarming of swimming particles.
abstract: Three-dimensional simulations with fully resolved hydrodynamics are performed to study the collective motion of model swimmers in bulk and confinement. Calculating the dynamic structure factor, we clarified that the swarming in bulk systems can be understood as a pseudoacoustic mode. Under confinement between flat parallel walls, this pseudoacoustic mode leads to a traveling wavelike motion. This swarming behavior is due purely to the hydrodynamic interactions between the swimmers and depends strongly on the type and strength of swimming (i.e., pusher or puller).
authors.affiliation: Department of Chemical Engineering, Kyoto University, Kyoto 615-8510, Japan.
authors.forename: Norihiro
authors.initials: N
authors.lastname: Oyama
authors.affiliation: Department of Chemical Engineering, Kyoto University, Kyoto 615-8510, Japan.
authors.forename: John Jairo
authors.initials: JJ
authors.lastname: Molina
authors.affiliation: Department of Chemical Engineering, Kyoto University, Kyoto 615-8510, Japan.
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Yamamoto