Fluid dynamics

  • Article |

    A macroscopic analogue of a spin system is shown to emerge in an ensemble of droplets bouncing on the surface of a vibrating bath, revealing symmetry-breaking phenomena such as ‘magnetic’ ordering.

    • Pedro J. Sáenz
    • , Giuseppe Pucci
    •  & John W. M. Bush
  • Article |

    High-performance hydrodynamic simulations show that the skeletal structure of the deep-sea sponge Euplectella aspergillum reduces the hydrodynamic stresses on it, while possibly being beneficial for feeding and reproduction.

    • Giacomo Falcucci
    • , Giorgio Amati
    •  & Sauro Succi
  • Article |

    Cellular fluidics provides a platform of unit-cell-based, three-dimensional structures for the deterministic control of multiphase flow, transport and reaction processes.

    • Nikola A. Dudukovic
    • , Erika J. Fong
    •  & Eric B. Duoss
  • Article |

    A weakly ionized gas jet impinging on a water surface is shown to produce a more stable cavity than does a neutral gas jet, with implications for plasma–liquid interactions.

    • Sanghoo Park
    • , Wonho Choe
    •  & Uroš Cvelbar
  • Article |

    In a rotating reactor, immiscible or pairwise-immiscible liquids organize into stable but internally agitated concentric layers, enabling multistep syntheses and separations of reaction mixtures.

    • Olgierd Cybulski
    • , Miroslaw Dygas
    •  & Bartosz A. Grzybowski
  • Article |

    Manipulation of the effective gravity of an oscillating liquid creates stable buoyancy in the lower surface of a liquid layer levitating above air, allowing bodies to float upside down.

    • Benjamin Apffel
    • , Filip Novkoski
    •  & Emmanuel Fort
  • Article |

    Wall-free liquid channels surrounded by an immiscible magnetic liquid can be used to create liquid circuitry or to transport human blood without damaging the blood cells by moving permanent magnets.

    • Peter Dunne
    • , Takuji Adachi
    •  & Thomas M. Hermans
  • Article |

    A theoretical framework describing the hydrodynamic interactions between a passive particle and an active medium in out-of-equilibrium systems predicts long-range Lévy flights for the diffusing particle driven by the density of the active component.

    • Kiyoshi Kanazawa
    • , Tomohiko G. Sano
    •  & Adrian Baule
  • Article |

    Microfluidic systems controlled by a single driving pressure are programmed to exhibit complex flow-switching schemes and a fluid analogue of Braess’s paradox by exploiting fluid inertia and network design.

    • Daniel J. Case
    • , Yifan Liu
    •  & Adilson E. Motter
  • Letter |

    Numerical modelling of rotating turbulent convective flows shows that the length scale of convection in planetary cores is set by the flow speed and not by the fluid viscosity.

    • Céline Guervilly
    • , Philippe Cardin
    •  & Nathanaël Schaeffer
  • Letter |

    A solid-state propulsion system can sustain powered flight, as demonstrated by an electroaerodynamically propelled heavier-than-air aeroplane.

    • Haofeng Xu
    • , Yiou He
    •  & Steven R. H. Barrett
  • Letter |

    The measurement of an alignment between the angular momentum of a non-central collision between heavy ions and the spin of emitted particles reveals that the fluid produced in the collision is extremely vortical.

    • L. Adamczyk
    • , J. K. Adkins
    •  & M. Zyzak
  • Letter |

    Polarity reversals caused by dynamo waves are demonstrated in a magnetohydrodynamic model that is relevant to planetary cores, suggesting a possible mechanism of geomagnetic reversals.

    • Andrey Sheyko
    • , Christopher C. Finlay
    •  & Andrew Jackson
  • Letter |

    The gradual development of a turbulent cascade in a weakly interacting homogeneous Bose gas is observed on application of a periodic driving force.

    • Nir Navon
    • , Alexander L. Gaunt
    •  & Zoran Hadzibabic
  • Letter |

    The pressure-driven flow rate through individual carbon nanotubes is precisely determined from the hydrodynamics of emerging water jets, revealing unexpectedly large and radius-dependent surface slippage.

    • Eleonora Secchi
    • , Sophie Marbach
    •  & Lydéric Bocquet
  • Letter |

    Experiments, asymptotic theory and computer simulations of wall-bounded shear flow uncover a bifurcation scenario that explains the transition from localized turbulent patches to fully turbulent flow.

    • Dwight Barkley
    • , Baofang Song
    •  & Björn Hof
  • Letter |

    Droplets of mixed water and propylene glycol deposited on clean glass exhibit a contact angle but do not suffer from contact line pinning; their motion can be controlled by the vapour emitted from neighbouring droplets to create a variety of autonomous fluidic machines with integrated sensing and motility capabilities.

    • N. J. Cira
    • , A. Benusiglio
    •  & M. Prakash
  • Letter |

    The parameters critical in determining the behaviour of a fibrous medium wetted with a single liquid drop are identified as fibre flexibility, fibre geometry and drop volume.

    • C. Duprat
    • , S. Protière
    •  & H. A. Stone
  • Letter |

    When a bubble on a liquid–gas or solid–gas interface ruptures, the general expectation is that the bubble vanishes. Here, it is shown that in many cases interfacial bubbles do not simply vanish when they rupture, but rather create numerous small bubbles via unexpected folding of the ruptured bubble as it retracts. The process may increase the efficiency of rupture-induced aerosol dispersal.

    • James C. Bird
    • , Riëlle de Ruiter
    •  & Howard A. Stone
  • Letter |

    The Southern Ocean is potentially a substantial sink of anthropogenic carbon dioxide; however, the regulation of this carbon sink by the wind-driven Ekman flow, mesoscale eddies and their interaction is under debate. Here, a high-resolution ocean circulation and carbon cycle model is used to study intra-annual variability in anthropogenic carbon dioxide over a two-year time period; the Ekman flow is found to be the primary mechanism of anthropogenic carbon dioxide transport across the Antarctic polar front.

    • T. Ito
    • , M. Woloszyn
    •  & M. Mazloff