Effect of an insoluble surfactant film on the stability of the concentration-driven Marangoni flow

2014 ◽  
Vol 49 (1) ◽  
pp. 26-36 ◽  
Author(s):  
A. I. Mizev ◽  
A. I. Trofimenko
Keyword(s):  
Marangoni Flow ◽  
Insoluble Surfactant ◽  
Surfactant Film ◽  
The Stability

scholarly journals Thermo-capillary flow in a Hele-Show cell as a tool for research of the dynamics of insoluble surfactant monolayer

2019 ◽  
Vol 213 ◽  
pp. 02073
Author(s):  
Andrey Shmyrov
Keyword(s):  
Thermocapillary Convection ◽  
Capillary Flow ◽  
Surface Film ◽  
Complete Information ◽  
Stagnant Zone ◽  
Shear Stresses ◽  
Sufficient Information ◽  
Tangential Stresses ◽  
Insoluble Surfactant ◽  
Surfactant Film

The occurrence of thermocapillary convection in a Hele-Shaw cell in the presence of the surfactant film on the free surface is experimentally investigated. It is shown that at certain values of the control parameter two different zones are formed on the surface – the zone free from impurities and the stagnant zone. In the first zone, the onset and development of an intense Marangoni convection is observed, while in the stagnant zone the velocity of the motion on the surface is lower by about two orders of magnitude. This study clearly demonstrates that the analysis of the temperature profile provides sufficient information about both the distribution of tangential stresses over the surface and the degree of compression of the surfactant film. In addition, due to a simple linear law of temperature variation on the surface of the stagnant zone, the distribution of the surfactant molecules over the surface can be predicted based on the known equation of state for the film of the examined surfactant. Thus, the application of a set of simple experimental techniques to the examined model problem allowed us to obtain complete information on the state of a complex system consisting of a liquid layer and a surface film of the surfactant, the structure of the volumetric flow, the velocity of the liquid at the surface, the distribution of shear stresses and surfactant molecules over the surface.

Instability of an oscillatory fluid layer with insoluble surfactants

2008 ◽  
Vol 595 ◽  
pp. 461-490 ◽  
Author(s):  
PENG GAO ◽  
XI-YUN LU
Keyword(s):  
Floquet Theory ◽  
Critical Reynolds Number ◽  
Fluid Layer ◽  
Travelling Waves ◽  
Chebyshev Collocation Method ◽  
Insoluble Surfactant ◽  
Wide Range ◽  
The Stability ◽  
Bounded Below ◽  
First Time

The linear stability of an infinite fluid layer with a deformable free surface covered by an insoluble surfactant and bounded below by a horizontal rigid plate oscillating in its own plane is studied based on the Floquet theory. The differential system governing the stability problem for perturbations of arbitrary wavenumbers is solved numerically by a Chebyshev collocation method. Stability boundaries are obtained in a wide range of amplitude and frequency of the modulation as well as surfactant elasticity. Results show that the presence of the surfactant may significantly stabilize (destabilize) the flow by raising (lowering) the critical Reynolds number associated with the onset of instability. The effect of the surfactant plays a stabilizing role for small surfactant elasticity and a destabilizing one for relatively large surfactant elasticity. The destabilizing effect of the surfactant on the stability of flows with a zero-shear surface is found for the first time. The disturbance modes in the form of travelling waves may be induced by the surfactant and dominate the instability of the flow.

Instability of Marangoni flow in the presence of an insoluble surfactant. Experiments

2013 ◽  
Vol 219 (1) ◽  
pp. 89-98 ◽  
Author(s):  
A. Mizev ◽  
A. Trofimenko ◽  
D. Schwabe ◽  
A. Viviani
Keyword(s):  
Marangoni Flow ◽  
Insoluble Surfactant

The Stability of Evaporating Thin Liquid Film Containing Insoluble Surfactant on Heated Substrate

2012 ◽  
Vol 614-615 ◽  
pp. 191-194
Author(s):  
Chun Xi Li ◽  
Bing Lu ◽  
Xue Min Ye
Keyword(s):  
Liquid Film ◽  
Evolution Equations ◽  
Thin Liquid Film ◽  
Nonlinear Evolution Equations ◽  
Linear Stability Theory ◽  
Film Stability ◽  
Heated Substrate ◽  
Insoluble Surfactant ◽  
The Stability ◽  
Evaporation Number

Flow of evaporating thin liquid film containing insoluble surfactant on a uniformally heated substrate is considered in this paper. Coupled nonlinear evolution equations for the film thickness and surfactant concentration are derived on the base of lubrication theory and reasonable boundary conditions. The flow stability of the thin liquid film has been studied using normal mode method according to the linear stability theory. The results show that the film stability is promoted by increasing the Capillary number and the surfactant Peclet number, while increasing the Marangoni number, the interface resistance number, the vapor recoil number and the evaporation number can reduce the stability of the system.

Electrochemistry and catalysis with vitamin B12 hexacarboxylate in an insoluble surfactant film

Langmuir ◽  
1993 ◽  
Vol 9 (1) ◽  
pp. 315-322 ◽  
Author(s):  
Chang Ling Miaw ◽  
Naifei Hu ◽  
James M. Bobbitt ◽  
Zhenkun Ma ◽  
Maryam F. Ahmadi ◽  
...  
Keyword(s):  
Vitamin B12 ◽  
Insoluble Surfactant ◽  
Surfactant Film

scholarly journals Effects of magnetic fields on capillary-gravity waves in the presence of magnetic surfactants

2018 ◽  
Vol 185 ◽  
pp. 09002
Author(s):  
Alexander V. Zhukov
Keyword(s):  
Magnetic Field ◽  
Free Surface ◽  
External Magnetic Field ◽  
Elastic Constant ◽  
Gravity Waves ◽  
Wave Motion ◽  
Liquid Surface ◽  
Critical Value ◽  
Surfactant Film ◽  
The Stability

The stability of capillary-gravity wave motion on horizontal free surface of viscous noncompressible fluid in the presence of magnetic surfactant in an external magnetic field was studied. It is shown that for normal as well as for tangential external magnetic field the horizontal free liquid surface is unstable for field strength exceeding some critical value that does not depend on the elastic constant of the surfactant film. However, for oblique external magnetic field the stability of the free surface depends not only on the field value but also on the surfactant elastic constant.

Open discussion

1982 ◽  
Vol 99 ◽  
pp. 605-613
Author(s):  
P. S. Conti
Keyword(s):  
Buenos Aires ◽  
Large Mass ◽  
List Type ◽  
Common Phenomenon ◽  
Open Discussion ◽  
The Stability ◽  
Ring Nebulae

Conti: One of the main conclusions of the Wolf-Rayet symposium in Buenos Aires was that Wolf-Rayet stars are evolutionary products of massive objects. Some questions:–Do hot helium-rich stars, that are not Wolf-Rayet stars, exist?–What about the stability of helium rich stars of large mass? We know a helium rich star of ∼40 MO. Has the stability something to do with the wind?–Ring nebulae and bubbles : this seems to be a much more common phenomenon than we thought of some years age.–What is the origin of the subtypes? This is important to find a possible matching of scenarios to subtypes.

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