title: Vortex-induced morphology on a two-fluid interface and the transitions.
abstract: We investigate experimentally the steady flows in a cylinder containing two immiscible liquids, with the primary fluid being driven by the upper boundary rotating at constant speeds. The system exhibits interesting interplays between the flow fields and the morphology of the interface, with evidence showing that the remarkable flattop structure is a consequence of the vortex breakdown discovered decades ago, and that the deformability of the interface also feedbacks positively to the development of the vortices. Monitoring the topological structure of the flow fields defines the base states and transitions behind the morphology, whereas our survey over different aspect ratios also reveals rich phenomena of surface instabilities accompanying these steady states.
authors.affiliation: Institute of Physics, Academia Sinica, Taipei 11529, Taiwan.
authors.forename: J-C
authors.initials: JC
authors.lastname: Tsai
authors.affiliation: Institute of Physics, Academia Sinica, Taipei 11529, Taiwan.
authors.forename: C-Y
authors.initials: CY
authors.lastname: Tao
authors.affiliation: Department of Physics, National Taiwan Normal University, Taipei, Taiwan.
authors.forename: Y-C
authors.initials: YC
authors.lastname: Sun
authors.affiliation: Department of Physics, National Taiwan University, Taipei, Taiwan.
authors.forename: C-Y
authors.initials: CY
authors.lastname: Lai
authors.affiliation: Department of Physics, National Taiwan University, Taipei, Taiwan.
authors.forename: K-H
authors.initials: KH
authors.lastname: Huang
authors.affiliation: Institute of Physics, Academia Sinica, Taipei 11529, Taiwan.|Integrative Stem Cell Center, China Medical University, Taichung, Taiwan.
authors.forename: W-T
authors.initials: WT
authors.lastname: Juan
authors.affiliation: Department of Physics, National Taiwan Normal University, Taipei, Taiwan.
authors.forename: J-R
authors.initials: JR
authors.lastname: Huang
mesh_terms: D057446:Hydrodynamics; D008962:Models, Theoretical; D009038:Motion; D013024:Soybean Oil; D013499:Surface Properties; D014783:Viscosity; D014867:Water
chemical_list: D014867:Water; D013024:Soybean Oil