Stability of a jet in confined pressure-driven biphasic flows at low reynolds numbers.
Motivated by its importance for microfluidic applications, we study the stability of jets formed by pressure-driven concentric biphasic flows in cylindrical capillaries. The specificity of this variant of the classical Rayleigh-Plateau instability is the role of the geometry which imposes confinement and Poiseuille flow profiles. We experimentally evidence a transition between situations where the flow takes the form of a jet and regimes where drops are produced. We describe this as the transition from convective to absolute instability, within a simple linear analysis using lubrication theory for flows at low Reynolds number, and reach remarkable agreement with the data.
Guillot
Pierre
P
Rhodia Laboratoire du Futur, Unité mixte Rhodia-CNRS, Université Bordeaux I, 178 Avenue du Docteur Schweitzer, 33608 Pessac, France. pierre.guillot@eu.rhodia.com
Colin
Annie
A
Utada
Andrew S
AS
Ajdari
Armand
A