Abstract
This study presents a theoretical and numerical investigation of interfacial flows of oxidised liquid metals in a shallow annular channel in the absence of inertial effects. For the first time, viscoplastic surface behaviour induced by oxidation is modelled using a bi-viscosity law within a framework that also accounts for interfacial curvature governed by the Young–Laplace equation. By solving a coupled bulk-surface flow system, the effects of surface rheology, contact angle, and dimensionless capillary length on surface velocity and surface shear rate profiles are quantified. Results highlight the competing influences of hydrophobicity and viscoplasticity on surface and bulk flow characteristics and demonstrate that accurate modelling of such systems necessitates inclusion of both curvature and non-Newtonian surface effects. In appropriate limits, our numerical results are validated against semi-analytical solutions. Our findings offer insights relevant to metal casting applications.
| Original language | English |
|---|---|
| Article number | 105498 |
| Number of pages | 16 |
| Journal | Journal of Non-Newtonian Fluid Mechanics |
| Volume | 346 |
| Early online date | 27 Sept 2025 |
| DOIs | |
| Publication status | Published - Dec 2025 |
Bibliographical note
Copyright © 2025 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (https://creativecommons.org/licenses/by/4.0/).Funding
This work was supported by the Engineering and Physical Science Research Council, award number: EP/Y031644/1. The authors acknowledge the use of the High Performance Computing (HPC) facilities and the associated support services at Aston University (TAURUS HPC) in the completion of this work. SIMaP laboratory is part of the LabEx Tec 21 (Investissements d’Avenir—Grant No. ANR-11-LABX-0030).
Keywords
- Viscoplastic
- Interfacial
- Wetting/dewetting
- Bi-viscosity