Molecular Thermal Phenomena in an Ultrathin Lubrication Liquid Film of Linear Molecules Between Solid Surfaces

2005 ◽  
Vol 9 (3) ◽  
pp. 265-279 ◽  
Author(s):  
Taku Ohara ◽  
Daichi Torii
Keyword(s):  
Liquid Film ◽  
Solid Surfaces ◽  
Linear Molecules ◽  
Thermal Phenomena

scholarly journals On mechanism of the bubble bouncing from hydrophilic and hydrophobic solid surfaces

2015 ◽  
Vol 70 (1) ◽  
Author(s):  
Jan Zawała ◽  
Piotr Zawała ◽  
Kazimierz Małysa
Keyword(s):  
Liquid Film ◽  
Solid Surfaces ◽  
Deformation Degree ◽  
Bubble Deformation ◽  
Surface Time ◽  
The Moment ◽  
Highly Hydrophobic ◽  
Energy Dissipated ◽  
Bubble Collision ◽  
Kinetics Of

AbstractThe kinetics of collision and bouncing of an air bubble on hydrophilic and hydrophobic solid surfaces immersed in distilled water is reported. We carried out the experiments and compared the bubble collision and bouncing courses on the stagnant and vibrating, with a controlled frequency and amplitude, solid/liquid interface. For stagnant interface differences in the outcome of the bubble collisions with hydrophilic and hydrophobic solid surfaces are resulting from different stability of the intervening liquid film formed between the colliding bubble and these surfaces. The liquid film was unstable at Teflon surface, where the three-phase contact (TPC) and the bubble attachment were observed, after dissipation of most of the kinetic energy associated with the bubble motion. For vibrated solid surface it was shown that kinetics of the bubble bouncing is independent on the hydrophilic/hydrophobic properties of the surface. Similarly like at water/glass hydrophilic interface, even at highly hydrophobic Teflon surface time of the bubble collisions and bouncing was prolonged almost indefinitely. This was due to the fact that the energy dissipated during the collision was re-supplied via interface vibrations with a properly adjusted acceleration. The analysis of the bubble deformation degree showed that this effect is related to a constant bubble deformation, which determined constant radius of the liquid film, large enough to prevent the draining liquid film from reaching the critical thickness of rupture at the moment of collision. The results obtained prove that mechanism of the bubble bouncing from various interfaces depends on interrelation between rates of two simultaneously going processes: (i) exchange between kinetic and surface energies of the system and (ii) drainage of the liquid film separating the interacting interfaces.

A molecular dynamics study of heat transfer over an ultra-thin liquid film with surfactant between solid surfaces

2019 ◽  
Vol 126 (18) ◽  
pp. 185302 ◽  
Author(s):  
Yuting Guo ◽  
Donatas Surblys ◽  
Yoshiaki Kawagoe ◽  
Hiroki Matsubara ◽  
Taku Ohara
Keyword(s):  
Heat Transfer ◽  
Molecular Dynamics ◽  
Liquid Film ◽  
Thin Liquid Film ◽  
Solid Surfaces

Simultaneous measurement of dynamic force and spatial thin film thickness between deformable and solid surfaces by integrated thin liquid film force apparatus

Soft Matter ◽  
2016 ◽  
Vol 12 (44) ◽  
pp. 9105-9114 ◽  
Author(s):  
Xurui Zhang ◽  
Plamen Tchoukov ◽  
Rogerio Manica ◽  
Louxiang Wang ◽  
Qingxia Liu ◽  
...  
Keyword(s):  
Thin Film ◽  
Film Thickness ◽  
Liquid Film ◽  
Simultaneous Measurement ◽  
Thin Liquid Film ◽  
Solid Surfaces ◽  
Dynamic Force ◽  
Thin Film Thickness

An Instability for Parallel Sliding of Solid Surfaces Separated by a Viscous Liquid Film

1976 ◽  
Vol 98 (1) ◽  
pp. 157-166 ◽  
Author(s):  
B. N. Banerjee ◽  
R. A. Burton
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Film Thickness ◽  
Liquid Film ◽  
Coefficient Of Thermal Expansion ◽  
Solid Surfaces ◽  
Wave Number ◽  
Seal Failure ◽  
Viscous Liquid Film ◽  
Surface Disturbance

Thermoelastic phenomena in lubricated face type seals are analyzed for possible instabilities which may lead to large surface deformations and seal failure. Thresholds of such instabilities are found where a small, steadily moving, surface disturbance will neither grow nor decay. For a good thermal conductor sliding on a good insulator, several such thresholds exist. Only one, however, falls within a reasonable operating range, the critical sliding speed being Ucrit=hκ¯KMμαM where h¯ is the nominal film-thickness, κ the wave number of the disturbance, KM the thermal conductivity of the conductor and αM its coefficient of thermal expansion, and μ the viscosity of the oil. Expressions are given for the approximate limits of h¯ within which such a threshold lies. Finally, it is shown that, as expected, a disturbance will grow when U > Ucrit and decay when U < Ucrit.

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