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Biphasic fluid oscillator with coaxial injection and upstream mass and momentum transfer

Heuberger, M. ; Gottardo, L. ; Dressler, M. ; Hufenus, R.

In: Microfluidics and Nanofluidics, 2015, vol. 19, no. 3, p. 653-663

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    Titel
    • Biphasic fluid oscillator with coaxial injection and upstream mass and momentum transfer
    Autor
    • Heuberger, M.. Laboratory for Advanced Fibers, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen, Switzerland
    • Gottardo, L.. Laboratory for Advanced Fibers, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen, Switzerland
    • Dressler, M.. Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, MA, USA
    • Hufenus, R.. Laboratory for Advanced Fibers, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen, Switzerland
    Dokumententyp
    • Postprint
    Sprache
    • Englisch
    Veröffentlicht in
    • Microfluidics and Nanofluidics, 2015, vol. 19, no. 3, p. 653-663. Springer Berlin Heidelberg
    Andere elektronische Ausgabe
    OAI-PMH-ID
    • oai:doc.rero.ch:331543
    Summary
    We present model experiments with biphasic flow and computational fluid dynamics (CFD) simulations for concentric co-flow scenarios. A lower viscosity fluid is injected into an outer phase of reduced thickness. Static design modifications of the injection geometry are then studied to allow for self-adjusting upstream transfer of mass and momentum. Such static arrangement gives rise to a simple biphasic fluid oscillator that can produce individual droplets at high rates and high aspect ratios. Frequency analysis and CFD simulations are invoked to shed light on the physics of this dynamically forced jet breakup and to identify relevant control parameters. In addition, we illustrate how a terminal baffle plate at the nozzle can produce a split-up into multiple dripping or jetting threads depending on its relative rotational symmetry with the upstream mass transfer. The here-presented distinctive injection geometry bears potential for simple ways of controlled jet breakup in microfluidics devices, which currently primarily rely on Rayleigh-Taylor breakup or the costly introduction of intricate actuators or compliant elements. Most notably, this oscillatory injector has potential for application in biphasic melt-flow spinnerets to realize advanced fiber core structures during melt-spinning.