Capillary Displacement of Viscous Liquids
Peter L L Walls1, Grégoire Dequidt1,2, James C Bird1
1Department of Mechanical Engineering, Boston University , Boston, Massachusetts 02215, United States.
Langmuir : the ACS Journal of Surfaces and Colloids
|March 15, 2016
Summary
The Lucas-Washburn law for capillary rise is modified when the displaced fluid
Area of Science:
- Fluid dynamics
- Surface science
- Physical chemistry
Background:
- Capillary rise is governed by surface tension and gravity.
- The Lucas-Washburn law describes early-stage capillary rise, neglecting displaced fluid viscosity and gravity.
- Understanding deviations from this law is crucial for various applications.
Purpose of the Study:
- To investigate the early viscous dynamics of capillary rise when displaced fluid properties are significant.
- To explore modifications to the Lucas-Washburn law under these conditions.
- To analyze the influence of gravity on both early and late viscous regimes.
Main Methods:
- Combination of experimental observations and theoretical modeling.
- Systematic variation of fluid viscosities to assess their impact.
- Analysis of capillary rise dynamics under different gravitational influences.
Main Results:
- The Lucas-Washburn law's predictions are altered when the displaced fluid's viscosity is comparable to or greater than the wetting fluid.
- Gravity significantly affects capillary rise dynamics even in the early viscous regime.
- A modified understanding of capillary flow dynamics is established.
Conclusions:
- The influence of displaced fluid viscosity and gravity must be considered for accurate capillary rise modeling.
- Deviations from the standard Lucas-Washburn law are predictable and quantifiable.
- This research provides a more comprehensive model for capillary-driven fluid transport.
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