Abstract
The onset of instability with respect to the spatio-temporally growing disturbance in a viscosity-stratified two-layer liquid film flow is analyzed. The known results obtained from the temporal theory of instability show that the flow is unstable in the limit of zero Reynolds numbers. The present theory predicts the neutral stability in the same limit. The discrepancy is explained. Based on the mechanical energy equation, a new mechanism of instability is found. The new mechanism is associated with the convective nature of the disturbance that is not Galilei invariant.
Similar content being viewed by others
References
Yih, C. S. Instability due to viscosity stratification. J. Fluid Mech. 27(2), 337–352 (1967)
Renardy, Y. Instability at the interface between two shearing fluids in a channel. Phys. Fluids 28(12), 3441–3443 (1985)
Renardy, Y. The thin-layer effect and interfacial stability in a two-layer Couette flow with similar liquids. Phys. Fluids 30(6), 1627–1637 (1987)
Chen, K. P. Interfacial instabilities in stratified shear flows involving multiple viscous and viscoelastic fluids. Appl. Mech. Rev. 48(11), 763–776 (1995)
Tilley, B. S., Davis, S. H., and Bankoff, S. G. Linear stability theory of two-layer fluid flow in an inclined channel. Phys. Fluids 6(12), 3906–3922 (1994)
Tilley, B. S., Davis, S. H., and Bankoff, S. G. Nonlinear long-wave stability of superposed fluids in an inclined channel. J. Fluid Mech. 277, 55–83 (1994)
Hooper, A. P. Long-wave instability at the interface between two viscous fluids: thin layer effects. Phys. Fluids 28(6), 1613–1618 (1985)
Hooper, A. P. and Boyd, W. G. C. Shear-flow instability at the interface between two viscous fluids. J. Fluid Mech. 128, 507–528 (1983)
Hooper, A. P. and Grimshaw, R. Nonlinear instability at the interface between two viscous fluids. Phys. Fluids 28(1), 37–45 (1985)
Kao, T. W. Role of viscosity stratification in the stability of two-layer flow down an incline. J. Fluid Mech. 33, 561–572 (1968)
Loewenherz, D. S. and Lawrence, C. J. The effect of viscosity stratification on the stability of a free surface flow at low Reynolds number. Phys. Fluids A 1(10), 1686–1693 (1989)
Chen, K. P. Wave formation in the gravity-driven low-Reynolds number flow of two liquid films down an inclined plane. Phys. Fluids A 5(12), 3038–3048 (1993)
Wang, C. K., Seaborg, J. J., and Lin, S. P. Instability of multi-layered liquid films. Phys. Fluids 21(10), 1669–1673 (1978)
Jiang, W. Y., Helenbrook, B., and Lin, S. P. Inertialess instability of a two-layer liquid film flow. Phys. Fluids 16(3), 652–663 (2004)
Weinstein, S. J. and Kurz, M. R. Long-wavelength instabilities in three-layer flow down an incline. Phys. Fluids A 3(11), 2680–2687 (1991)
Weinstein, S. J. and Chen, K. P. Large growth rate instabilities in three-layer flow down an incline in the limit of zero Reynolds number. Phys. Fluids 11(11), 3270–3282 (1999)
Kliakhandler, I. L. and Sivashinsky, G. I. Viscous damping and instabilities in stratified liquid film flowing down a slightly inclined plane. Phys. Fluids 9(1), 23–30 (1997)
Pozrikidis, C. Gravity-driven creeping flow of two adjacent layers through a channel and down a plane wall. J. Fluid Mech. 371, 345–376 (1998)
Kliakhandler, I. L. Long interfacial waves in multilayer thin films and coupled Kuramoto-Sivashinsky equations. J. Fluid Mech. 391, 45–65 (1999)
Jiang, W. Y., Helenbrook, B., and Lin, S. P. Low Reynolds number instabilities in three-layer flow down an inclined wall. J. Fluid Mech. 539, 387–416 (2005)
Brooke Benjamin, T. The development of three-dimensional disturbances in an unstable film of liquid flowing down an inclined plane. J. Fluid Mech. 10(3), 401–419 (1961)
Yih, C. S. Stability of two-dimensional parallel flows for three-dimensional disturbances. Quart. Appl. Math. 12, 434–435 (1955)
Squire, H. B. On the stability for three-dimensional disturbances of viscous fluid flow between parallel walls. Proc. R. Soc. Lond. A 142(847), 621–628 (1933)
Author information
Authors and Affiliations
Corresponding author
Additional information
Contributed by Zhe-wei ZHOU
Project supported by the National Natural Science Foundation of China (Nos. 10702038 and 10772107), the National Science Foundation of USA (No. CTS-0138057), and the Shanghai Leading Academic Discipline Project (No. Y0103)
Rights and permissions
About this article
Cite this article
Wang, Zl., Lin, S.P. & Zhou, Zw. Spatio-temporal instability of two-layer liquid film at small Reynolds numbers. Appl. Math. Mech.-Engl. Ed. 31, 1–12 (2010). https://doi.org/10.1007/s10483-010-0101-x
Received:
Revised:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10483-010-0101-x