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Updated: Jul 3, 2026
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Investigating the Three-dimensional Flow Separation Induced by a Model Vocal Fold Polyp
Published on: February 3, 2014
Periodic folding of viscous sheets
1UMR 7579 CNRS, Institut de Physique du Globe, 4 place Jussieu, 75252 Paris Cédex 05, France.
Summary
Fluid sheets periodically fold when falling, a phenomenon studied using thin-layer equations. Researchers found folding frequency depends on fluid properties and buoyancy, transitioning from forced to free folding. This work aligns with experimental results.
Area of Science:
- Fluid mechanics
- Rheology
- Geophysics
Background:
- Periodic folding of falling viscous fluid sheets is a common instability.
- This phenomenon occurs in diverse applications, from food processing to geophysics.
Purpose of the Study:
- To numerically determine the folding frequency of a 2D viscous fluid sheet.
- To investigate the influence of initial thickness, pouring speed, fall height, and fluid properties on folding.
Main Methods:
- Asymptotic thin-layer equations were used to model stretching-bending deformation.
- Numerical solutions were employed to calculate folding frequency.
Main Results:
- Folding frequency is dependent on sheet thickness, pouring speed, fall height, and fluid properties.
- Increased buoyancy causes a bifurcation from kinematically driven "forced" folding to buoyancy-balanced "free" folding.
Conclusions:
- Numerical predictions of folding frequency show good agreement with laboratory experiments.
- The study elucidates the transition between different folding regimes based on fluid properties and external forces.
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