Dry spot growth criterion for isothermal liquid films on a horizontal substrate

2017 ◽  
Vol 24 (3) ◽  
pp. 383-387
Author(s):  
L. I. Maltsev ◽  
Yu. S. Podzharov ◽  
O. A. Kabov
Keyword(s):  
Liquid Films ◽  
Growth Criterion ◽  
Horizontal Substrate ◽  
Dry Spot

Vortex Generation in a Thin Liquid Layer under the Effect of Moving Heater

2010 ◽  
Vol 3 (2) ◽  
pp. 40-46
Author(s):  
Pavel A. Kuibin ◽  
Oleg V. Sharypov
Keyword(s):  
Free Surface ◽  
Liquid Layer ◽  
Liquid Velocity ◽  
Liquid Films ◽  
Theoretical Background ◽  
Thin Liquid Layer ◽  
Small Reynolds Numbers ◽  
State Regime ◽  
Horizontal Substrate ◽  
Dry Spot

An effect of moving local heater on the flow structure in a thin liquid layer on horizontal substrate is analyzed. The 2-D problem is considered under boundary layer approximation. For the case of small Reynolds numbers the steadystate equation is derived for description of the liquid film deformation in the accompanying frame of reference. The obtained equation can be applied in particular at horizontal substrate orientation. The results of simulations of the film thickness, pressure and liquid velocity at a given model temperature distribution on a free surface are presented. The dependencies of liquid viscosity and density on the temperature are neglected in the model, as well as heat, mass and momentum transfer at the free surface. It is shown that even in absence of liquid motion under gravity action the motion of local heater provides the existence of steady-state regime without film breakdown and dry spot formation. As outcome the theoretical background for new scheme of experimental study of phenomena in non-isothermal liquid films is developed.

Drying of solids wetted by thin liquid films

1990 ◽  
Vol 68 (9) ◽  
pp. 1084-1088 ◽  
Author(s):  
F. Brochard Wyart ◽  
J. Daillant
Keyword(s):  
Molecular Size ◽  
Liquid Films ◽  
Nucleation And Growth ◽  
Thin Liquid Films ◽  
Wetting Layer ◽  
Nonwetting Liquid ◽  
Dry Patch ◽  
Dry Spot ◽  
Wetting Liquid ◽  
Equilibrium Thickness

(i) A film of a nonwetting liquid is not stable. If it is thick (thickness e ≥ 1000 Å) it is metastable and evolves via nucleation and growth of a dry spot. If it is thin, it is unstable against spinodal decomposition (amplification of thermal undulations) and breaks into microscopic droplets of size ~e2/a (a = a molecular size), (ii) A film made with a wetting liquid is metastable and tends to shrink whenever e < eS (the equilibrium thickness of the wetting layer). Contrary to case (i) where the growth of a dry patch is controlled by capillary forces, the central role for drying in case (ii) is played by long-range forces, and the only process is nucleation and growth.

scholarly journals Marangoni-driven liquid films rising out of a meniscus onto a nearly-horizontal substrate

PAMM ◽  
2005 ◽  
Vol 5 (1) ◽  
pp. 617-618
Author(s):  
P. L. Evans ◽  
A. Münch
Keyword(s):  
Liquid Films ◽  
Horizontal Substrate

scholarly journals Contact line dynamics on a substrate coated with a fluoropolymer

2021 ◽  
Vol 2119 (1) ◽  
pp. 012132
Author(s):  
D Y Kochkin ◽  
A L Bogoslovtseva ◽  
O A Kabov
Keyword(s):  
Contact Line ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Water Layer ◽  
Liquid Films ◽  
Solid Substrate ◽  
Chemical Vapor Deposition Method ◽  
Deposition Method ◽  
Hot Wire ◽  
Dry Spot

Abstract This work investigates the dynamics of the contact line during the propagation of a dry spot in a water layer on a solid substrate. The substrate is coated with fluoropolymer by using a hot wire chemical vapor deposition method. The dry spot is generated using a thermocapillary mechanism caused by the heating of the substrate from below by the laser. By analyzing schlieren images, the dependence of the velocity of the contact line during the propagation of a dry spot was obtained for various initial thicknesses of liquid films.

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