Flow around a droplet suspended in a yield-stress fluid

Pourzahedi, Ali and Chaparian, Emad and Frigaard, Ian A. (2024) Flow around a droplet suspended in a yield-stress fluid. Physics of Fluids, 36 (2). 023102. ISSN 1070-6631 (https://doi.org/10.1063/5.0187377)

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Abstract

We investigate the minimal yield-stress required in order to hold static an ellipsoidal Newtonian droplet inside a yield-stress liquid. This critical limit (Yc) is influenced by the droplet aspect ratio (χ), the interfacial tension (γ), and the viscosity ratio (M) between the droplet and the surrounding liquid, as well as the ratio of the yield-stress to the buoyancy stress (Y). The droplet will remain trapped by the liquid yield-stress for Y > Y c . Our study bridges the gap in the published results between those calculated for bubbles ( M → 0 ) and the solid rigid particles ( M → ∞ ), being of practical use for those estimating the design of stable yield-stress emulsions. In general, the critical yield number increases with the interfacial tension and the droplet aspect ratio and will decrease with the droplet viscosity. For spherical droplets, our results computed for yield numbers below Yc suggest that the spherical shaped droplet may propagate in steady motion.

  • Item type:Article
    ID code:88171
    Dates:
    Date
    Event
    2 February 2024
    Published
    6 January 2024
    Accepted
    13 November 2023
    Submitted
    Notes:Copyright © 2024 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Pourzahedi, A, Chaparian, E & Frigaard, IA 2024, 'Flow around a droplet suspended in a yield-stress fluid', Physics of Fluids, vol. 36, no. 2, 023102, and may be found at https://doi.org/10.1063/5.0187377.
    Subjects:Science > Physics
    Department:University of Strathclyde > University of Strathclyde
    Depositing user: Pure Administrator
    Date deposited:14 Feb 2024 11:39
    Last modified:18 Apr 2024 10:34
    URI:https://strathprints.strath.ac.uk/id/eprint/88171
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