title: Chaotic self-sustaining structure embedded in the turbulent-laminar interface.
abstract: An interface structure between turbulence and laminar flow is investigated in two-dimensional channel flow. This spatially localized structure not only sustains itself but also converts the laminar state into turbulence actively. A filtered simulation technique is introduced to understand the invading process as an inhomogeneity-induced self-sustaining coherent structure, which consists of a meandering jet on bulk-region and near-wall vortex pairs. A phenomenological model, called the ejection-jet cycle, reveals the relationship between the spatial inner structure of the interface and the invading speed. This model gives insight on the inner-outer interaction in wall-turbulence.
authors.affiliation: Department of Physics and Astronomy, Graduate School of Science, Kyoto University, Kyoto 606-8224, Japan.
authors.forename: Toshiki
authors.initials: T
authors.lastname: Teramura
authors.affiliation: Department of Physics and Astronomy, Graduate School of Science, Kyoto University, Kyoto 606-8224, Japan.
authors.forename: Sadayoshi
authors.initials: S
authors.lastname: Toh