Instability and dynamics of thin viscoelastic liquid films
G Tomar1, V Shankar, S K Shukla
1Department of Mechanical Engineering, Indian Institute of Technology, Kanpur 208016, India. gtm@iitk.ac.in
The European Physical Journal. E, Soft Matter
|June 21, 2006
Summary
This study investigates hole growth in viscoelastic films, finding that while fluid rheology accelerates instability, it doesn't alter the fundamental shape or dewetting dynamics. Viscoelasticity impacts growth rate but not morphology.
Area of Science:
- Fluid dynamics
- Materials science
- Rheology
Background:
- Thin films are susceptible to instability and rupture.
- Van der Waals forces drive dewetting phenomena.
- Understanding viscoelastic fluid behavior is crucial for film stability.
Purpose of the Study:
- Investigate hole instability, rupture, and growth in Jeffreys-type viscoelastic films.
- Analyze the influence of fluid rheology on dewetting dynamics.
- Compare linear stability analysis with nonlinear numerical simulations.
Main Methods:
- Linear stability analysis of governing equations for arbitrary wave numbers.
- Nonlinear numerical simulations of long-wave, nonlinear differential equations.
- Analysis of free surface evolution and hole dynamics.
Main Results:
- Fluid rheology significantly affects instability growth rate but not the dominant length scale.
- Neglecting inertia and solvent dynamics leads to nonphysical singularities in growth rate.
- Nonlinear simulations confirm linear analysis findings.
- Viscoelasticity accelerates hole growth but preserves morphological characteristics.
Conclusions:
- Jeffreys-type viscoelasticity accelerates dewetting but does not change the fundamental shape of holes.
- Rescaled time reveals identical hole shape and dynamics for Newtonian and viscoelastic liquids.
- Accurate modeling requires considering inertia and solvent dynamics to avoid nonphysical results.
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