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Whipping of electrified liquid jets.
Josefa Guerrero1, Javier Rivero2, Venkata R Gundabala1
1School of Physics, Georgia Institute of Technology, Atlanta, GA 30332; and.
Summary
Electrified jets in microfluidic devices form stable helical structures. Jet stability depends on coflowing liquid properties and charge, with chaotic behavior observed under specific conditions.
Area of Science:
- Fluid dynamics
- Microfluidics
- Electrified jets
Background:
- Nonaxisymmetric instabilities in electrified jets are not fully understood.
- Microfluidic devices offer a controlled environment for studying fluid phenomena.
Purpose of the Study:
- Investigate the behavior of electrified jets in a coflowing liquid within a microfluidic device.
- Characterize the resulting structures and their stability.
Main Methods:
- Applying an electric field to a moderately conducting liquid jet surrounded by a coflowing liquid.
- Utilizing a glass-based microfluidic device for experimentation.
- Performing numerical analysis to validate experimental observations.
Main Results:
- Observed a steady-state, helicoidal (helical) structure with a constant opening angle.
- Found that the helicoidal wave's phase speed depends solely on the jet's charge.
- Determined that coflowing liquid properties critically influence jet stability.
- Identified chaotic behavior when the inner liquid's characteristic time dominates.
Conclusions:
- The study reveals a novel steady-state helical structure in electrified jets.
- Jet stability is intricately linked to coflowing fluid properties and charge.
- Numerical analysis supports the experimental observation of conical helix formation.