Switching between different types of stability isles in films over topographies
In the present study, we performed comprehensive experiments and direct Navier–Stokes computations on the linear stability of gravity-driven film flows. We focused on the switching between different types of stability isles, appearing in viscous films over inclined topographies, which describes an abrupt change of the flow’s free-surface stability. We systematically varied the inclination angle, the liquid, the substrate’s shape and the corrugation’s periodicity and uncovered when this phenomenon appears and how it proceeds. Our combined experimental and numerical work unveiled that the switching is of a universal nature as it can be induced by a slight variation of one of the multitude of completely differing parameters mentioned above. The in-depth investigation of this phenomenon presented in this article is of interest for the technical exploitation of film flows as it puts the reader into the position to avoid high-risk situations where a small change of the system’s configuration leads to a significantly different system response.
Unable to display preview. Download preview PDF.
We wish to thank Marion Märkl, Stephan Eißner and Dominik Schröder for their help in carrying out parts of the experiments and kindly acknowledge the DAAD for providing a visiting fellowship for Prof. Trifonov, Grant No. 91577374, which made this project possible.
- 5.Kraus, A., Bar-Cohen, A., Wative, A.A.: Cooling Electronic Equipment, 3rd edn. Wiley, Hoboken (2006)Google Scholar
- 6.Fair, J.R., Bravo, J.R.: Distillation columns containing structured packing. Chem. Eng. Prog. 86, 19–29 (1990)Google Scholar
- 8.Webb, R.L.: Principles of Enhanced Heat Transfer. Wiley, New York (1994)Google Scholar
- 14.Kapitza, P.L.: Wave flow of thin layers of a viscous fluid. Zh. Eksp. Teor. Fiz. 18, 3–28 (1948)Google Scholar
- 25.Chang, H.C., Demekhin, E.A.: Complex Wave Dynamics on Thin Films. Elsevier, Amsterdam (2002)Google Scholar
- 36.Trifonov, Y.Y.: Viscous liquid film flows over a vertical corrugated surface and the film free surface stability. Russ. J. Eng. Thermophys. 10(2), 129–145 (2000)Google Scholar
- 42.Tseluiko, D., Blyth, M.G., Papageorgiou, D.T.: Stability of film flow over inclined topography based on a long-wave nonlinear model. J. Fluid Mech. 729, 638–671 (2013)Google Scholar