Soap film flows: Statistics of two-dimensional turbulence

1999 ◽  
Vol 11 (8) ◽  
pp. 2167-2177 ◽  
Author(s):  
P. Vorobieff ◽  
M. Rivera ◽  
R. E. Ecke
Keyword(s):  
Soap Film ◽  
Two Dimensional ◽  
Film Flows

scholarly journals The direct enstrophy cascade of two-dimensional soap film flows

2014 ◽  
Vol 26 (5) ◽  
pp. 055105 ◽  
Author(s):  
M. K. Rivera ◽  
H. Aluie ◽  
R. E. Ecke
Keyword(s):  
Soap Film ◽  
Two Dimensional ◽  
Enstrophy Cascade ◽  
Film Flows

scholarly journals Asymptotic turbulent friction in 2D rough-walled flows

2021 ◽  
Vol 7 (5) ◽  
pp. eabc6234
Author(s):  
Alexandre Vilquin ◽  
Julie Jagielka ◽  
Simeon Djambov ◽  
Hugo Herouard ◽  
Patrick Fisher ◽  
...  
Keyword(s):  
Roughness Length ◽  
Soap Film ◽  
Standard Theory ◽  
Practical Relevance ◽  
Two Dimensional ◽  
Turbulent Friction ◽  
Spectral Exponent ◽  
Pipe Flows ◽  
Turbulent Spectrum ◽  
Film Flows

The friction f is the property of wall-bounded flows that sets the pumping cost of a pipeline, the draining capacity of a river, and other variables of practical relevance. For highly turbulent rough-walled pipe flows, f depends solely on the roughness length scale r, and the f − r relation may be expressed by the Strickler empirical scaling f ∝ r1/3. Here, we show experimentally that for soap film flows that are the two-dimensional (2D) equivalent of highly turbulent rough-walled pipe flows, f ∝ r and the f − r relation is not the same in 2D as in 3D. Our findings are beyond the purview of the standard theory of friction but consistent with a competing theory in which f is linked to the turbulent spectrum via the spectral exponent α: In 3D, α = 5/3 and the theory yields f ∝ r1/3; in 2D, α = 3 and the theory yields f ∝ r.

Two-dimensional soap-film patterns

2017 ◽  
pp. 12-29
Author(s):  
David Lovett ◽  
John Tilley
Keyword(s):  
Soap Film ◽  
Two Dimensional

The Generation of Two-Dimensional Vortices by Transverse Oscillation of a Soap Film

1997 ◽  
Vol 9 (9) ◽  
pp. S2-S2 ◽  
Author(s):  
P. D. Weidman ◽  
V. O. Afenchenko ◽  
A. B. Ezersky ◽  
S. V. Kiyashko ◽  
M. I. Rabinovich
Keyword(s):  
Soap Film ◽  
Transverse Oscillation ◽  
Two Dimensional

scholarly journals The dynamics of a viscous soap film with soluble surfactant

2001 ◽  
Vol 442 ◽  
pp. 387-409 ◽  
Author(s):  
JEAN-MARC CHOMAZ
Keyword(s):  
Film Thickness ◽  
Elastic Wave ◽  
Surfactant Concentration ◽  
Stokes Equations ◽  
Film Surface ◽  
Soap Film ◽  
Fluid Viscosity ◽  
Two Dimensional ◽  
Leading Order ◽  
Soap Films

Nearly two decades ago, Couder (1981) and Gharib & Derango (1989) used soap films to perform classical hydrodynamics experiments on two-dimensional flows. Recently soap films have received renewed interest and experimental investigations published in the past few years call for a proper analysis of soap film dynamics. In the present paper, we derive the leading-order approximation for the dynamics of a flat soap film under the sole assumption that the typical length scale of the flow parallel to the film surface is large compared to the film thickness. The evolution equations governing the leading-order film thickness, two-dimensional velocities (locally averaged across the film thickness), average surfactant concentration in the interstitial liquid, and surface surfactant concentration are given and compared to similar results from the literature. Then we show that a sufficient condition for the film velocity distribution to comply with the Navier–Stokes equations is that the typical flow velocity be small compared to the Marangoni elastic wave velocity. In that case the thickness variations are slaved to the velocity field in a very specific way that seems consistent with recent experimental observations. When fluid velocities are of the order of the elastic wave speed, we show that the dynamics are generally very specific to a soap film except if the fluid viscosity and the surfactant solubility are neglected. In that case, the compressible Euler equations are recovered and the soap film behaves like a two-dimensional gas with an unusual ratio of specific heat capacities equal to unity.

The generation of two-dimensional vortices by transverse oscillation of a soap film

1998 ◽  
Vol 10 (2) ◽  
pp. 390-399 ◽  
Author(s):  
V. O. Afenchenko ◽  
A. B. Ezersky ◽  
S. V. Kiyashko ◽  
M. I. Rabinovich ◽  
P. D. Weidman
Keyword(s):  
Soap Film ◽  
Transverse Oscillation ◽  
Two Dimensional

Schlieren technique in soap film flows

2017 ◽  
Vol 58 (5) ◽  
Author(s):  
M. I. Auliel ◽  
F. Castro Hebrero ◽  
R. Sosa ◽  
G. Artana
Keyword(s):  
Soap Film ◽  
Schlieren Technique ◽  
Film Flows

Electrostatically controlled large-amplitude, non-axisymmetric waves in thin film flows down a cylinder

2013 ◽  
Vol 736 ◽  
Author(s):  
A. W. Wray ◽  
D. T. Papageorgiou ◽  
O. K. Matar
Keyword(s):  
Thin Film ◽  
Field Strength ◽  
Electric Field ◽  
Evolution Equation ◽  
Electric Field Strength ◽  
Numerical Solutions ◽  
Outer Cylinder ◽  
Outer Electrode ◽  
Two Dimensional ◽  
Film Flows

AbstractWe examine the dynamics of a thin film flowing under gravity down the exterior of a vertically aligned inner cylinder, with a co-aligned, concentric cylinder acting as an outer electrode; the space between the outer cylinder and the film is occupied by an inviscid gas. The stability of the interface is studied when it is subjected to an electric field, applied by imposing a potential difference between the two cylinders. Leaky-dielectric theory is used in conjunction with asymptotic reduction, in the large-conductivity limit, to derive a single, two-dimensional evolution equation for the interfacial location, which accounts for gravity, capillarity, and electrostatic effects. A linear stability analysis is carried out which shows that non-axisymmetric modes become more dominant with increasing electric field strength. Our fully two-dimensional numerical solutions of the evolution equation demonstrate qualitative agreement between the trends observed in the nonlinear regime and those predicted by linear theory. These numerical solutions also show that, depending on the electric field strength and the relative proximity of the outer electrode, the interface either remains spatially uniform, or exhibits either axisymmetric or, importantly, non-axisymmetric travelling waves. The effect of wave formation on the interfacial area is investigated in connection with the use of electric fields to control thin film flows to enhance heat and mass transfer rates.

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