Drop formation from an orifice in an electric field

AIChE Journal ◽  
1988 ◽  
Vol 34 (9) ◽  
pp. 1577-1580 ◽  
Author(s):  
C. H. Byers ◽  
J. J. Perona
Keyword(s):  
Electric Field ◽  
Drop Formation

Drop formation via breakup of a liquid bridge in an AC electric field

2006 ◽  
Vol 302 (1) ◽  
pp. 294-307 ◽  
Author(s):  
Beom Seok Lee ◽  
Hye-Jung Cho ◽  
Jeong-Gun Lee ◽  
Nam Huh ◽  
Jeong-Woo Choi ◽  
...  
Keyword(s):  
Electric Field ◽  
Liquid Bridge ◽  
Drop Formation ◽  
Ac Electric Field

scholarly journals Theoretical and experimental studies of charged drop formation in a uniform electric field.

1981 ◽  
Vol 14 (3) ◽  
pp. 178-182 ◽  
Author(s):  
TORU TAKAMATSU ◽  
YOSHIKI HASHIMOTO ◽  
MANABU YAMAGUCHI ◽  
TAKASHI KATAYAMA
Keyword(s):  
Electric Field ◽  
Experimental Studies ◽  
Uniform Electric Field ◽  
Drop Formation ◽  
Charged Drop

Dynamics of Drop Formation in an Electric Field

1999 ◽  
Vol 213 (1) ◽  
pp. 218-237 ◽  
Author(s):  
Patrick K. Notz ◽  
Osman A. Basaran
Keyword(s):  
Electric Field ◽  
Drop Formation

Analytical Study of the Instability Between Two Liquids Flowing in a Channel and Subjected to Parallel or Normal Electric Field

2008 ◽  
Author(s):  
A. Kerem Uguz ◽  
Nadine Aubry
Keyword(s):  
Electric Field ◽  
Analytical Study ◽  
Microfluidic Devices ◽  
Maximum Growth ◽  
Drop Formation ◽  
Plane Poiseuille Flow ◽  
Flat Interface ◽  
Material Deposition ◽  
Normal Electric Field ◽  
Complete Set

The electro-hydrodynamic linear stability of a flat interface between two viscous, immiscible and incompressible liquids in plane Poiseuille flow has been shown to be useful in microfluidic devices. In some applications (e.g., material deposition) stability is desired, and in others (e.g., mixing or drop formation) instability needs to be induced. Depending on the direction of the electric field, i.e., parallel or normal to the flat interface, and in the case of fast electric times, it was shown analytically and without solving the complete set of equations that the electric field can either stabilize or destabilize the interface [1]. In this paper, we fully solve the equations and determine the maximum growth rates and the critical wavenumbers in the conductivity versus permittivity ratio space.

Dynamics of drop formation from submerged orifices under the influence of electric field

2018 ◽  
Vol 30 (12) ◽  
pp. 122104 ◽  
Author(s):  
Manash Pratim Borthakur ◽  
Gautam Biswas ◽  
Dipankar Bandyopadhyay
Keyword(s):  
Electric Field ◽  
Drop Formation

Dynamics of drop formation from a capillary in the presence of an electric field

1996 ◽  
Vol 326 ◽  
pp. 239-263 ◽  
Author(s):  
Xiaoguang Zhang ◽  
Osman A. Basaran
Keyword(s):  
Surface Tension ◽  
Field Strength ◽  
Electric Field ◽  
Applied Electric Field ◽  
High Speed ◽  
Drop Formation ◽  
Large Radius ◽  
Charge Effects ◽  
Satellite Drops ◽  
Thread Length

This paper reports an experimental study of the effects of an externally applied electric field on the dynamics of drop formation in the dripping mode from a vertical metal capillary. The fluid issuing out of the capillary is a viscous liquid, the surrounding ambient fluid is air, and the electric field is generated by establishing a potential difference between the capillary and a horizontal, circular electrode of large radius placed downstream of the capillary outlet. By means of an ultra-high-speed video system that is capable of recording up to 12000 frames per second, special attention is paid to the dynamics of the liquid thread that connects the primary drop that is about to detach and fall from the capillary to the rest of the conical liquid mass that is hanging from it. The experiments show that as the strength of the electric field increases, the volume of the primary drop decreases whereas the maximum length attained by the thread increases. The reduction in the volume of primary drops and the increase in the length of threads occur because the effective electromechanical surface tension of the fluid interface falls as the field strength rises. For the highly conducting drops of aqueous NaCl solutions studied in this work, the increase in thread length is due solely to the rising importance of normal electric stress relative to the falling importance of surface tension. However, as the conductivity of the drop liquid decreases, the thread length is further increased on account of the stabilizing influence exerted by the increasing electric shear stress that acts on the charged liquid–gas interface. Two new phenomena are also reported that have profound implications for electrohydrodynamics and practical applications. First, it is shown that whereas the liquid thread always ruptures at its downstream end in the absence of an applied electric field or when the field strength is low, it ruptures at its upstream end when the field strength is sufficiently high. Since satellite drops are produced directly from the thread once both of its ends have ruptured, the change in the mechanism of breakup with field strength influences the dynamics and fate of satellite drops. Second, it is demonstrated that the generation of satellites, which are often undesirable in applications, can be suppressed by the judicious application of an electric field. This is accomplished by using a field of moderate strength to induce charges of the opposite sign on the nearby surfaces of the satellite drop and the liquid that remains pendant from the tube following thread rupture. At high field strengths, induced charge effects are too weak to compete with net charge effects: the satellite is repelled by the pendant drop and falls under gravity as a distinct entity.

Resolution in photoelectron microscopy

1991 ◽  
Vol 49 ◽  
pp. 458-459
Author(s):  
G. F. Rempfer
Keyword(s):  
Electron Microscopy ◽  
Electric Field ◽  
Ultraviolet Light ◽  
Uniform Field ◽  
Virtual Image ◽  
Lens System ◽  
Photoemission Electron Microscopy ◽  
Planar Electrode ◽  
Electron Lens ◽  
Photoemission Electron

In photoelectron microscopy (PEM), also called photoemission electron microscopy (PEEM), the image is formed by electrons which have been liberated from the specimen by ultraviolet light. The electrons are accelerated by an electric field before being imaged by an electron lens system. The specimen is supported on a planar electrode (or the electrode itself may be the specimen), and the accelerating field is applied between the specimen, which serves as the cathode, and an anode. The accelerating field is essentially uniform except for microfields near the surface of the specimen and a diverging field near the anode aperture. The uniform field forms a virtual image of the specimen (virtual specimen) at unit lateral magnification, approximately twice as far from the anode as is the specimen. The diverging field at the anode aperture in turn forms a virtual image of the virtual specimen at magnification 2/3, at a distance from the anode of 4/3 the specimen distance. This demagnified virtual image is the object for the objective stage of the lens system.

Field-assisted ionization theory for microscopists

1994 ◽  
Vol 52 ◽  
pp. 820-821
Author(s):  
Patrick P. Camus
Keyword(s):  
Electric Field ◽  
Electron Tunneling ◽  
Ionization Probability ◽  
Critical Distance ◽  
Tunneling Probability ◽  
Field Ionization ◽  
Radius Of Curvature ◽  
Field Evaporation ◽  
A Value ◽  
Ion Emission

The theory of field ion emission is the study of electron tunneling probability enhanced by the application of a high electric field. At subnanometer distances and kilovolt potentials, the probability of tunneling of electrons increases markedly. Field ionization of gas atoms produce atomic resolution images of the surface of the specimen, while field evaporation of surface atoms sections the specimen. Details of emission theory may be found in monographs.Field ionization (FI) is the phenomena whereby an electric field assists in the ionization of gas atoms via tunneling. The tunneling probability is a maximum at a critical distance above the surface,xc, Fig. 1. Energy is required to ionize the gas atom at xc, I, but at a value reduced by the appliedelectric field, xcFe, while energy is recovered by placing the electron in the specimen, φ. The highest ionization probability occurs for those regions on the specimen that have the highest local electric field. Those atoms which protrude from the average surfacehave the smallest radius of curvature, the highest field and therefore produce the highest ionizationprobability and brightest spots on the imaging screen, Fig. 2. This technique is called field ion microscopy (FIM).

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