Diffusion of curvature on a sheared semi-infinite film

Ryo Satomi, Paul Grassia, Simon Cox, Gennady Mishuris, Leo Lue

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

The viscous froth model is used to study the evolution of a long and initially straight soap film which is sheared by moving its endpoint at a constant velocity in a direction perpendicular to the initial film orientation. Film elements are thereby set into motion as a result of the shear, and the film curves. The simple scenario described here enables an analysis of the transport of curvature along the film, which is important in foam rheology, in particular for energy-relaxing ‘topological transformations’. Curvature is shown to be transported diffusively along films, with an effective diffusivity scaling as the ratio of film tension to the viscous froth drag coefficient. Computed (finite-length) film shapes at different times are found to approximate well to the semi-infinite film and are observed to collapse with distances rescaled by the square root of time. The tangent to the film at the endpoint reorients so as to make a very small angle with the line along which the film endpoint is dragged, and this angle decays roughly exponentially in time. The computed results are described in terms of a simple asymptotic solution corresponding to an infinite film that initially contains a right-angled corner.
LanguageEnglish
Article number20130359
Number of pages18
JournalProceedings A: Mathematical, Physical and Engineering Sciences
Volume469
Issue number2159
DOIs
Publication statusPublished - 11 Sep 2013

Fingerprint

Curvature
curvature
viscous drag
Angle
Drag Coefficient
soaps
Soaps (detergents)
drag coefficients
Rheology
Drag coefficient
Foam
Asymptotic Solution
Diffusivity
rheology
tangents
Square root
foams
Tangent line
Perpendicular
Straight

Keywords

  • viscous froth model
  • foam rheology
  • curvature-driven motion
  • Surface Evolver
  • diffusion of curvature
  • asymptotic analysis

Cite this

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Diffusion of curvature on a sheared semi-infinite film. / Satomi, Ryo; Grassia, Paul; Cox, Simon; Mishuris, Gennady; Lue, Leo.

In: Proceedings A: Mathematical, Physical and Engineering Sciences, Vol. 469, No. 2159, 20130359, 11.09.2013.

Research output: Contribution to journalArticle

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