The instability of non-Newtonian boundary-layer flows over rough rotating disks

A.A Alqarni, B. Alveroğlu, Paul Griffiths, S. J. Garrett

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    17 Citations (Scopus)
    107 Downloads (Pure)

    Abstract

    We are concerned with the local linear convective instability of the incompressible boundary-layer flows over rough rotating disks for non-Newtonian fluids. Using the Carreau model for a range of shear-thinning and shear-thickening fluids, we determine, for the first time, steady-flow profiles under the partial-slip model for surface roughness. The subsequent linear stability analyses of these flows (to disturbances stationary relative to the disk) indicate that isotropic and azimuthally-anisotropic (radial grooves) surface roughness leads to the stabilisation of both shear-thinning and -thickening fluids. This is evident in the behaviour of the critical Reynolds number and growth rates of both Type I (inviscid cross flow) and Type II (viscous streamline curvature) modes of instability. The underlying physical mechanisms are clarified using an integral energy equation.
    Original languageEnglish
    Article number104174
    JournalJournal of Non-Newtonian Fluid Mechanics
    Volume273
    Early online date9 Oct 2019
    DOIs
    Publication statusPublished - Nov 2019

    Bibliographical note

    NOTICE: this is the author’s version of a work that was accepted for publication in Journal of Non-Newtonian Fluid Mechanics. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Non-Newtonian Fluid Mechanics, 273 (2019) DOI: 10.1016/j.jnnfm.2019.104174

    © 2019, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/

    Keywords

    • Carreau fluid
    • Convective instability
    • Laminar boundary layer
    • Non-Newtonian

    ASJC Scopus subject areas

    • Chemical Engineering(all)
    • Materials Science(all)
    • Condensed Matter Physics
    • Mechanical Engineering
    • Applied Mathematics

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