scholarly journals Rebound and scattering of motile Chlamydomonas algae in confined chambers

Soft Matter ◽  
2021 ◽  
Author(s):  
Albane Thery ◽  
Yuxuan Wang ◽  
Masha Dvoriashyna ◽  
Christophe Eloy ◽  
Florence Elias ◽  
...  
Keyword(s):  
Plateau Border

Motivated by recent experiments demonstrating that motile algae get trapped in draining foams, we study the trajectories of microorganisms confined in model foam channels (section of a Plateau border). We...

scholarly journals Critical bubble diameters and Plateau border dimensions for drainage in aqueous xanthan foams

2021 ◽  
Vol 612 ◽  
pp. 125682
Author(s):  
Loïc Desbordes ◽  
Agnès Grandjean ◽  
Fabien Frances ◽  
Hélène Lorcet ◽  
Sylvain Faure
Keyword(s):  
Plateau Border ◽  
Critical Bubble

Instability of a gravity current within a soap film

2014 ◽  
Vol 753 ◽  
Author(s):  
Raymond E. Goldstein ◽  
Herbert E. Huppert ◽  
H. Keith Moffatt ◽  
Adriana I. Pesci
Keyword(s):  
Fluid Flow ◽  
Gravity Current ◽  
Leading Edge ◽  
Soap Film ◽  
Plateau Border ◽  
Dynamic Variations ◽  
Characteristic Wavelength ◽  
Overall Stability ◽  
Stability Regime ◽  
Good Agreement

AbstractOne of the simplest geometries in which to study fluid flow between two soap films connected by a Plateau border is provided by a catenoid with a secondary film at its narrowest point. Dynamic variations in the spacing between the two rings supporting the catenoid lead to fluid flow between the primary and secondary films. When the rings are moved apart, while keeping their spacing within the overall stability regime of the films, after a rapid thickening of the secondary film the excess fluid in it starts to drain into the sloped primary film through the Plateau border at which they meet. This influx of fluid is accommodated by a local thickening of the primary film. Experiments described here show that after this drainage begins the leading edge of the gravity current becomes linearly unstable to a finite-wavelength fingering instability. A theoretical model based on lubrication theory is used to explain the mechanism of this instability. The predicted characteristic wavelength of the instability is shown to be in good agreement with experimental results. Since the gravity current advances into a film of finite, albeit microscopic, thickness this situation is one in which the regularization often invoked to address singularities at the nose of a thin film is physically justified.

Suction at the plateau border of a free falling film

1984 ◽  
Vol 101 (2) ◽  
pp. 462-466
Author(s):  
J Van Havenbergh ◽  
H Bussmann ◽  
P Joos
Keyword(s):  
Falling Film ◽  
Plateau Border ◽  
Free Falling

Excess energy of a plateau border at a wall

2005 ◽  
Vol 85 (1) ◽  
pp. 21-25 ◽  
Author(s):  
M. A. Fortes ◽  
P. I. C. Teixeira *
Keyword(s):  
Excess Energy ◽  
Plateau Border

The thinning of lamellae in surfactant-free foams with non-Newtonian liquid phase

2008 ◽  
Vol 616 ◽  
pp. 235-262 ◽  
Author(s):  
L. N. BRUSH ◽  
S. M. ROPER
Keyword(s):  
Liquid Phase ◽  
Shear Rate ◽  
Transition Region ◽  
Power Law ◽  
Capillary Number ◽  
Newtonian Liquid ◽  
Liquid Viscosity ◽  
Plateau Border ◽  
Shear Rates ◽  
Border Regions

Thinning rates of liquid lamellae in surfactant-free non-Newtonian gas–liquid foams, appropriate for ceramic or polymer melts and also in metals near the melting point, are derived in two dimensions by matched asymptotic analysis valid at small capillary number. The liquid viscosity is modelled (i) as a power-law function of the shear rate and (ii) by the Ellis law. Equations governing gas–liquid interface dynamics and variations in liquid viscosity are derived within the lamellar, transition and plateau border regions of a corner of the liquid surrounding a gas bubble. The results show that the viscosity varies primarily in the very short transition region lying between the lamellar and the Plateau border regions where the shear rates can become very large. In contrast to a foam with Newtonian liquid, the matching condition which determines the rate of lamellar thinning is non-local. In all cases considered, calculated lamellar thinning rates exhibit an initial transient thinning regime, followed by a t−2 power-law thinning regime, similar to the behaviour seen in foams with Newtonian liquid phase. In semi-arid foam, in which the liquid fraction is O(1) in the small capillary number, results explicitly show that for both the power-law and Ellis-law model of viscosity, the thinning of lamella in non-Newtonian and Newtonian foams is governed by the same equation, from which scaling laws can be deduced. This result is consistent with recently published experimental results on forced foam drainage. However, in an arid foam, which has much smaller volume fraction of liquid resulting in an increase in the Plateau border radius of curvature as lamellar thinning progresses, the scaling law depends on the material and the thinning rate is not independent of the liquid viscosity model parameters. Calculations of thinning rates, viscosities, pressures, interface shapes and shear rates in the transition region are presented using data for real liquids from the literature. Although for shear-thinning fluids the power-law viscosity becomes infinite at the boundaries of the internal transition region where the shear rate is zero, the interface shape, the pressure and the internal shear rates calculated by both rheological models are indistinguishable.

scholarly journals Surfactant flow between a Plateau border and a film during foam fractionation

2016 ◽  
Vol 143 ◽  
pp. 139-165 ◽  
Author(s):  
Paul Grassia ◽  
Sebastian Ubal ◽  
Maria Delia Giavedoni ◽  
Denny Vitasari ◽  
Peter James Martin
Keyword(s):  
Foam Fractionation ◽  
Plateau Border
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