Rivulet flow down a slippery substrate

Alshaikhi, Abdulwahed S. and Wilson, Stephen K. and Duffy, Brian R. (2020) Rivulet flow down a slippery substrate. Physics of Fluids, 32 (7). 072011. ISSN 1070-6631

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    Abstract

    A detailed analysis of small-scale locally unidirectional gravity-driven rivulet flow with prescribed volume flux down an inclined slippery substrate for a rivulet with either constant width (i.e., pinned contact lines) or constant contact angle is undertaken. In particular, we determine the effect of varying the Navier slip length λ (i.e., the strength of the slip at the solid-fluid interface) on the rivulet. The present analysis shows that the shape and size of the rivulet and the velocity within it depend strongly on the value of λ. Increasing the value of λ reduces the viscous resistance at the substrate and, hence, leads to a larger velocity within the rivulet, and so the prescribed flux is achieved with a smaller rivulet. In particular, in the limit of strong slip, λ → ∞, for a rivulet of a perfectly wetting fluid and a rivulet with constant width, the velocity becomes large and plug-like like O(λ1/2) ≫ 1, and the rivulet becomes shallow like O(λ-1/2) ≪ 1, while for a rivulet with positive constant contact angle, the velocity becomes large and plug-like like O(λ2/3) ≫ 1, and the rivulet becomes narrow like O(λ-1/3) ≪ 1 and shallow like O(λ-1/3) ≪ 1.

    Creators(s): Alshaikhi, Abdulwahed S. ORCID logoORCID: https://orcid.org/0000-0001-5608-1813, Wilson, Stephen K. ORCID logoORCID: https://orcid.org/0000-0001-7841-9643 and Duffy, Brian R. ORCID logoORCID: https://orcid.org/0000-0003-2687-7938;
    Item type:Article
    ID code:73043
    Keywords:rivulet flows, microfluidics, nanofluidics, mathematical physics, fluid dynamics, Mathematics, Mathematical Physics
    Subjects:Science > Mathematics
    Department:Faculty of Science > Mathematics and Statistics
    Strategic Research Themes > Ocean, Air and Space
    Strategic Research Themes > Measurement Science and Enabling Technologies
    Strategic Research Themes > Energy
    Strategic Research Themes > Advanced Manufacturing and Materials
    Depositing user: Pure Administrator
    Date deposited:06 Jul 2020 12:10
    Last modified:21 Sep 2020 02:39
    URI:https://strathprints.strath.ac.uk/id/eprint/73043
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