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Published on: February 3, 2014
Pinch-off singularities in rotating Hele-Shaw flows at high viscosity contrast
E Alvarez-Lacalle1, J Casademunt, J Eggers
1Departament de Física Aplicada, Universitat Politècnica de Catalunya, Marañon 50, E-08028 Barcelona, Spain.
Summary
In a rotating Hele-Shaw cell, dumbbell liquid patches evolve based on initial conditions. Rotation influences pinch-off via centrifugal and capillary forces, sometimes preventing it and other times inducing it.
Area of Science:
- Fluid dynamics
- Soft matter physics
Background:
- Hele-Shaw cells are used to study fluid flow in confined geometries.
- Liquid patch evolution is influenced by surface tension and external forces.
Purpose of the Study:
- To investigate the behavior of dumbbell-shaped liquid patches in a rotating Hele-Shaw cell.
- To understand the role of rotation in the pinch-off dynamics of liquid structures.
Main Methods:
- Lubrication theory was employed to model the fluid dynamics.
- Numerical simulations were performed to analyze the evolution of liquid patches.
Main Results:
- Dumbbell shapes either stretched indefinitely, formed droplets via pinch-off, or aggregated into a central drop.
- Rotation's interplay with centrifugal and capillary forces determined pinch-off outcomes.
- Rotation could delay or prevent pinch-off by stretching the fluid neck, or induce pinch-off where it wouldn't normally occur.
Conclusions:
- The dynamics of liquid dumbbells in rotating Hele-Shaw cells are complex and sensitive to initial conditions.
- Rotation significantly alters pinch-off phenomena, offering a mechanism to control droplet formation.
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