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Relevance of dynamic wetting in viscous fingering patterns
E Alvarez-Lacalle1, J Ortín, J Casademunt
1Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100, Israel.
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|October 10, 2006
Summary
Wetting effects at moving contact lines significantly alter viscous fingering patterns. Experiments reveal distinct morphologies in dry versus prewetted Hele-Shaw cells due to contact angle dynamics.
Area of Science:
- Fluid dynamics
- Interface phenomena
- Wettability studies
Background:
- Viscous fingering is a key instability in fluid dynamics.
- Hele-Shaw cells are standard experimental tools for studying fluid instabilities.
- The role of wetting effects at moving contact lines is not fully understood.
Purpose of the Study:
- To investigate the impact of wetting effects on viscous fingering patterns.
- To compare experimental results in dry and prewetted Hele-Shaw cells.
- To analyze the kinetic contribution to interface pressure drop.
Main Methods:
- Experiments conducted in a rotating Hele-Shaw cell.
- Comparison of viscous fingering patterns in dry and prewetted conditions.
- Numerical simulations to validate experimental findings.
Main Results:
- Consistent morphological differences observed between dry and prewetted Hele-Shaw cells.
- Contact angle dynamics in dry regions introduce a kinetic pressure drop contribution scaling with Ca(2/3).
- This kinetic contribution is significantly larger than the Park-Homsy correction.
Conclusions:
- Wetting effects at moving contact lines are crucial for viscous fingering.
- Standard Hele-Shaw equations are most accurate for prewetted cells.
- Contact angle dynamics play a significant role in interface pressure drop.
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