contact line dynamics of a liquid meniscus advancing in a microchannel with chemical heterogeneities...
TRANSCRIPT
Contact line dynamics of a liquid meniscus advancing in a microchannel with chemical heterogeneitiesC. Wylock1, M. Pradas2, B. Haut1, P. Colinet1 and S. Kalliadasis2
1 Université Libre de Bruxelles – Transfers, Interfaces and Processes2 Imperial College London – Chemical Engineering Department
International Conference on Multiscale Complex Fluid Flows and Interfacial Phenomena MULTIFLOW 2010Brussels, Belgium
Goal Gas-liquid meniscus moving in a "Hele-Shaw cell like "
microchannel Surface chemically heterogeneous spatial
distribution of wetting properties 2 configurations
Effect of chemical heterogeneities on meniscus dynamics ?
2D configuration 3D configuration
Page 2
Modelling Phase field approach
• f represents the 2 phases• Interface at f=0
Page 3
Modelling Phase field approach
• f represents the 2 phases• Interface at f=0
Equilibrium given by Ginzburg-Landau model
Free energy formulation
Double-well potential
Chemical potential
Page 4
Modelling Phase field approach
• f represents the 2 phases• Interface at f=0
Equilibrium given by Ginzburg-Landau model
Free energy formulation
Double-well potential
Chemical potential
Page 5
Modelling Wetting boundary condition
Conserved dynamic equation
Page 6
Standard deviation s= disorder strength
with[1]
[1] Cahn, J. Chem. Phys. 66 (1977), 3667
Results and discussion 2D configuration
• Typical simulation result• Statistical analysis on several disorder realisations
Page 7
Results and discussion 2D configuration
• Typical simulation result• Statistical analysis on several disorder realisations
Page 8
Results and discussion 2D configuration
• Typical simulation result• Statistical analysis on several disorder realisations
Page 9
Results and discussion 2D configuration
• Typical simulation result• Statistical analysis on several disorder realisations
Page 10
Results and discussion 2D configuration
• Typical simulation result• Statistical analysis on several disorder realisations
Page 11
Chemical disorder contact angle hysteresis enhanced by disorder strength
Results and discussion 3D configuration
• Typical simulation results• Contact line dynamics: preliminary analysis
─ interface width follows fractal dynamics
( scale-invariant growth)─ pinning-depinning effects─ avalanche dynamics
induced by the chemical disorder
Statistical analysis to perform for various disorder configurations
Page 12
Conclusion and future plans Phase field contact line dynamics in chemically
heterogeneous microchannel Chemical disorder induces
• 2D: hysteresis of contact angle hysteresis “jump” function of disorder strength
• 3D: kinetic roughening process of contact line motion, pinning-depinning effects
Future plans• Statistical analysis for 3D configuration:
─ Characterization of the scaling growth factors ─ Avalanche dynamics
Page 13
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Modelling Boundary conditions for 2D configuration
Page 15
Modelling Boundary conditions for 3D configuration
Page 16
Results and discussion 2D configuration
• Typical simulation result• Statistical analysis on several disorder realisations
Page 17
Chemical disorder contact angle hysteresis enhanced by disorder strength
Results and discussion 3D configuration
• Typical simulation results• Contact line dynamic: preliminary analysis
─ interface width growth follows fractal dynamic
Page 18
Results and discussion 3D configuration
• Typical simulation results• Contact line dynamic: preliminary analysis
─ interface width growth follows fractal dynamic
( size-invariant scaling factors)─ pinning-depinning effect s─ avalanche dynamic
Page 19
Avalanche sitePinning site