Linear stability analysis of a non-Newtonian liquid jet under AC electric fields

When DC electric fields are applied to a thin liquid film, the interface may become unstable and form a series of pillars. In this paper, we apply lubrication theory to examine the possibility of using AC electric fields to exert further control over the size and shape of the pillars. For perfect dielectric films, linear stability analysis shows that the influence of an AC field can be understood by considering an effective DC field. For leaky dielectric films, Floquet theory is applied to carry out the linear stability analysis, and it reveals that high frequencies may be used to inhibit the accumulation of interfacial free charge, leading to a lowering of growth rates and wavenumbers. Nonlinear simulations confirm the results of the linear stability analysis while also uncovering additional mechanisms for tuning overall pillar height and width. The results presented here may be of interest for the controlled creation of surface topographical features in applications such as patterned coatings and microelectronics.

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Linear stability analysis of a slightly viscoelastic liquid jet

Aerospace Science and Technology ◽

10.1016/j.ast.2012.11.005 ◽

2013 ◽

Vol 28 (1) ◽

pp. 249-256 ◽

Cited By ~ 9

Author(s):

Li-jun Yang ◽

Yuan-yuan Qu ◽

Qing-fei Fu ◽

Bing-rui Xu ◽

Wei Zhang ◽

...

Keyword(s):

Stability Analysis ◽

Linear Stability ◽

Linear Stability Analysis ◽

Viscoelastic Liquid ◽

Liquid Jet

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Linear stability analysis of a three-dimensional viscoelastic liquid jet surrounded by a swirling air stream

Journal of Non-Newtonian Fluid Mechanics ◽

10.1016/j.jnnfm.2012.10.011 ◽

2013 ◽

Vol 191 ◽

pp. 1-13 ◽

Cited By ~ 25

Author(s):

Li-Jun Yang ◽

Ming-Xi Tong ◽

Qing-Fei Fu

Keyword(s):

Stability Analysis ◽

Linear Stability ◽

Linear Stability Analysis ◽

Three Dimensional ◽

Viscoelastic Liquid ◽

Liquid Jet ◽

Air Stream

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Shear instability of an axisymmetric air–water coaxial jet

Journal of Fluid Mechanics ◽

10.1017/jfm.2018.167 ◽

2018 ◽

Vol 843 ◽

pp. 575-600 ◽

Cited By ~ 9

Author(s):

Jean-Philippe Matas ◽

Antoine Delon ◽

Alain Cartellier

Keyword(s):

Surface Tension ◽

Stability Analysis ◽

Linear Stability ◽

Linear Stability Analysis ◽

Convective Instability ◽

Scaling Laws ◽

Shear Instability ◽

Liquid Jet ◽

Absolute Instability ◽

Instability Waves

We 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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