On the shape of a rotating liquid drop in an electric field

We study and use the behaviour of a metallic liquid drop in the presence of an external electric field (EF). The droplet profile is governed by the stabilizing surface energy and the destabilizing electrostatic energy, with a critical voltage beyond which the droplet becomes unstable. We explore the EF-induced behaviour of low melting temperature alloy in the liquid state and observe that the droplet modifications in the linear response regime can be retained upon cooling the drop to the solid state. We demonstrate that this procedure can be used as an electrode with precise dimensions for applications in molecular and polymer electronics.

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On fluid motions induced by an electromagnetic field in a liquid drop immersed in a conducting fluid

Journal of Fluid Mechanics ◽

10.1017/s002211207200237x ◽

1972 ◽

Vol 51 (3) ◽

pp. 585-591 ◽

Cited By ~ 3

Author(s):

C. Sozou

Keyword(s):

Magnetic Field ◽

Electromagnetic Field ◽

Flow Field ◽

Electric Field ◽

Lorentz Force ◽

Liquid Drop ◽

Conducting Fluid ◽

Uniform Electric Field ◽

Tangential Electric Field ◽

Set Up

The deformation of a liquid drop immersed in a conducting fluid by the imposition of a uniform electric field is investigated. The flow field set up is due to the surface charge and the tangential electric field stress over the surface of the drop, and the rotationality of the Lorentz force which is set up by the electric current and the associated magnetic field. It is shown that when the fluids are poor conductors and good dielectrics the effects of the Lorentz force are minimal and the flow field is due to the stresses of the electric field tangential to the surface of the drop, in agreement with other authors. When, however, the fluids are highly conducting and poor dielectrics the effects of the Lorentz force may be predominant, especially for larger drops.

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Equilibrium of liquid drops under the effects of rotation and acoustic flattening: results from USML-2 experiments in Space

Journal of Fluid Mechanics ◽

10.1017/s0022112097007544 ◽

1998 ◽

Vol 354 ◽

pp. 43-67 ◽

Cited By ~ 17

Author(s):

C. P. LEE ◽

A. V. ANILKUMAR ◽

A. B. HMELO ◽

T. G. WANG

Keyword(s):

Experimental Study ◽

Angular Velocity ◽

Liquid Drop ◽

Sound Field ◽

Theoretical Models ◽

Liquid Drops ◽

Complementary Effect ◽

Rotating Liquid ◽

Neutral Equilibrium ◽

Effects Of Rotation

Previous Space-based experiments (Wang et al. 1994a) showed that a rotating liquid drop bifurcates into a two-lobed shape at a lower critical angular velocity, if it is flattened acoustically by the leviating sound field. In this work, we undertake a systematic experimental study of the effect of acoustic flattening on the rotational bifurcation of a liquid drop. We also look into the complementary effect of rotation on the equilibrium of an acoustically drastically flattened drop. Theoretical models are developed for each of the two effects and then woven into a unified picture. The first effect concerns neutral equilibrium, while the second concerns loss of equilibrium, neither of them involving instability. The theories agree well with the experiments.

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Experimental study of the oscillations of a rotating drop

Journal of Fluid Mechanics ◽

10.1017/s002211208500266x ◽

1985 ◽

Vol 158 ◽

pp. 317-327 ◽

Cited By ~ 20

Author(s):

P. Annamalai ◽

E. Trinh ◽

T. G. Wang

Keyword(s):

Experimental Study ◽

Analytical Study ◽

Liquid Drop ◽

Angular Speed ◽

Immiscible Fluid ◽

Drop Shape ◽

Free Decay ◽

Resonance Frequencies ◽

Rotating Liquid ◽

Relative Change

Two- and three-lobed oscillations of a rotating liquid drop immersed in an immiscible fluid of comparable density and the same angular velocity were studied experimentally. Using acoustically suspended drops, it has been found that the relative change in the resonance frequencies of the axisymmetric drop-shape oscillations Δωl/ωl(0) is proportional to the square of the normalized angular speed (Ω/ωl(0))2 when ωl > 2Ω. This is in agreement with a recent analytical study of the same problem. Some preliminary results regarding the effect of rotation on the free-decay rate of the two-lobed oscillations are also presented.

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Oscillations of a rotating liquid drop

Journal of Fluid Mechanics ◽

10.1017/s0022112084000963 ◽

1984 ◽

Vol 142 ◽

pp. 1-8 ◽

Cited By ~ 69

Author(s):

F. H. Busse

Keyword(s):

Surface Tension ◽

Circular Polarization ◽

Coriolis Force ◽

Liquid Drop ◽

Centrifugal Distortion ◽

Axis Of Rotation ◽

First Approximation ◽

Rotating Liquid ◽

Surrounding Fluid

The effect of rotation on the frequencies of oscillations of a liquid drop is investigated. It is assumed that the drop is imbedded in a fluid of the same or different density and that a constant surface tension acts on the interface. Rotation influences the oscillations through the Coriolis force and through the centrifugal distortion of the drop. For non-axisymmetric oscillations only the Coriolis force is important in first approximation and causes the expected splitting of the frequency for the two modes differing in their sign of circular polarization with respect to the axis of rotation. In the case of axisymmetric oscillations the centrifugal distortion and the Coriolis force combine to increase the frequency whenever the density ρi of the drop exceeds the density of ρ° of the surrounding fluid. For ρi < ρ° a decrease of the frequency of oscillation is possible for some modes of higher degree.

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