Investigation of Coalescence During Liquid Bridge Breakup
The process of fast and forced dewetting can be found in many industrial applications such as gravure printing, fibre spinning and functional printing. A possible form of dewetting encountered in these applications are liquid bridges. The dynamics of liquid bridges are governed by adhesive forces, surface tension, inertial and viscous forces. During the stretching of a liquid bridge a typical necking behaviour can be observed until the capillary forces at the menisci region dominate and lead to a pinch-off. After the breakup a filament and two residing volumes are formed. For industrial applications it is important to predict the sizes of those filaments and the residing volumes in order to design reliable industrial processes.
The subject of the proposed study is an experimental investigation of the dynamics and interactions of two liquid bridges, stretched simultaneously. The goal is to determine the conditions under which bridge stretching leads to coalescence.
The task includes
• further developing and expanding the existing test rig to apply liquid bridges at defined distances.
• experiments for finding the critical distance between two liquid bridges for different liquids, surface morphologies and accelerations.
• analysing the measurement data and identifying relevant parameters.
• documentation and presentation of the results.
Pre-requisites or requirements for the project
- Interest in experimental work
- MATLAB (not mandatory)
Recommended Literature and preparation
Eggers, J., & Villermaux, E. (2008). Physics of liquid jets. Reports on progress in physics, 71(3), 036601.
Frankel, I., & Weihs, D. (1985). Stability of a capillary jet with linearly increasing axial velocity (with application to shaped charges). Journal of Fluid Mechanics, 155, 289-307.
Plateau, J. (1857). I. Experimental and theoretical researches on the figures of equilibrium of a liquid mass withdrawn from the action of gravity.–Third series. Philosophical Magazine Series 4, 14(90), 1-22.
Rayleigh, L. (1879, January). On the capillary phenomena of jets. In Proc. R. Soc. London (Vol. 29, No. 196-199, pp. 71-97).
Weickgenannt, C., Roisman, I. V., & Tropea, C. (2015). Pinch-off of a stretching viscous filament and drop transport. New Journal of Physics, 17(8), 083059.
|Project available until||end of Aug 2018|