We consider the dynamics of spreading of a small drop over a smooth solid surface. The analysis is concerned with complete wetting and accounts for capillary, viscous, and van der Waals effects, with two spreading geometries considered: cylindrical and axisymmetric. A complete description of the dro
Wetting Film Dynamics
β Scribed by Oleg V. Voinov
- Publisher
- Elsevier Science
- Year
- 2000
- Tongue
- English
- Weight
- 74 KB
- Volume
- 226
- Category
- Article
- ISSN
- 0021-9797
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β¦ Synopsis
The spreading of a tiny macroscopic drop of a nonvolatile, completely wetting liquid over a flat solid is considered, assuming no gravitation. A liquid, in creeping, is subjected to capillary forces and van der Waals forces. This nonstationary and nonlinear problem in the dynamics of the wetting film from a droplet is studied using numerical modeling. The precursor wetting film motion is described by an evolution equation with conditions at the moving boundaries. The wetting line is regarded as an unknown boundary to be determined in the course of solution. A simplified equation for the wetting line dynamics is analyzed. The difference between the wetting line radius and a fixed (nonzero) radius is described by a diffusion time law. Results of numerical experiments show the simplified law of wetting to be valid over a wide range of spreading times (or a wide range of radii of the wetting line).
π SIMILAR VOLUMES
Two broad classes of models have been used to describe the motion of a contact line when the contact angle 0 deviates from the equilibrium value & : a) an Eyring approach, emphasizing the microscopic jump of a single molecule at the tip. b) a hydrodynamic approach, concentrating on the viscous losse
The a 1 parameter may readily be expressed via the parameter Consideration is given to the stationary motion of a capillary PΛin (9), a 1 Γ 2/3PΛ. Reference (5) provides a simplified meniscus of a wetting liquid over a solid at rather slow speeds contact angle relation relying upon the perturbation