Shear instability of an axisymmetric air–water coaxial jet
2018; Cambridge University Press; Volume: 843; Linguagem: Inglês
10.1017/jfm.2018.167
ISSN1469-7645
AutoresJean-Philippe Matas, Antoine Delon, Alain H. Cartellier,
Tópico(s)Fluid Dynamics and Thin Films
ResumoWe study the destabilization of a round liquid jet by a fast annular gas stream. We measure the frequency of the shear instability waves for several geometries and air/water velocities. We then carry out a linear stability analysis, and show that there are three competing mechanisms for the destabilization: a convective instability, an absolute instability driven by surface tension, and an absolute instability driven by confinement. We compare the predictions of this analysis with experimental results, and propose scaling laws for wave frequency in each regime. We finally introduce criteria to predict the boundaries between these three regimes.
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