Foam drainage on the microscale I. Modeling flow through single Plateau borders
S A Koehler1, S Hilgenfeldt, H A Stone
1Physics Department, Emory University, Atlanta, GA 303022, USA. skoehler@physics.emory.edu
Journal of Colloid and Interface Science
|July 24, 2004
Summary
Liquid drainage in foams flows through channels called Plateau borders. Narrow containers amplify the impact of exterior channels on drainage dynamics, while films contribute minimally unless liquid volumes are comparable to channels.
Area of Science:
- Fluid dynamics
- Foam physics
- Interfacial phenomena
Background:
- Foam drainage is crucial in various industrial processes.
- Liquid transport in foams occurs via channels (Plateau borders) and films.
- Understanding flow dynamics is key to controlling foam behavior.
Purpose of the Study:
- To model and analyze liquid drainage in foams.
- To investigate the influence of channel geometry and interface mobility on drainage.
- To compare flow rates in interior channels, exterior channels, and films.
Main Methods:
- Developed a mathematical model for unidirectional flow in Plateau borders.
- Assumed mobile liquid/gas interfaces with Newtonian surface viscosity.
- Employed numerical finite difference simulations.
- Derived analytical approximations for velocity fields.
Main Results:
- Exterior channels significantly impact drainage in narrow geometries.
- Films contribute little to drainage unless their liquid volume is substantial compared to channels.
- Flow rates differ significantly between interior channels, exterior channels, and films.
Conclusions:
- Container geometry plays a critical role in foam drainage.
- The contribution of films to drainage is generally negligible.
- The model provides insights into foam liquid transport mechanisms.
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