Estimation of Electric Field Between the Capillary and Wire-Netting Electrodes During the Electrostatic Atomization from Bio-emulsified Fuel

2010 ◽

Author(s):

Mohammad Passandideh Fard ◽

Mohammad Reza Mahpeykar ◽

Sajad Pooyan ◽

Mortaza Rahimzadeh

Keyword(s):

Surface Tension ◽

Free Surface ◽

Electric Field ◽

Stable State ◽

Surface Shape ◽

Liquid Jet ◽

Perfect Conductor ◽

Electric Force ◽

Electrostatic Atomization ◽

Liquid Free Surface

The behavior of a liquid jet in an electrostatic field is numerically simulated. The simulations performed correspond to a transient liquid jet leaving a capillary tube maintained at a high electric potential. The surface profile of the deforming jet is defined using the VOF scheme and the advection of the liquid free surface is performed using Youngs’ algorithm. Surface tension force is treated as a body force acting on the free surface using continuum surface force (CSF) method. To calculate the effect of the electric field on the shape of the free surface, the electrostatic potential is solved first. Next, the surface density of the electric charge and the electric field intensity are computed, and then the electric force is calculated. Liquid is assumed to be a perfect conductor, thus the electric force only acts on the liquid free surface and is treated similar to surface tension using the CSF method. To verify the simulation results, a simplified case of electrowetting phenomenon is simulated and free surface shape in stable state is compared with experimental results. Then the electrostatic atomization in spindle mode is simulated and the ability of the developed code to simulate this process is demonstrated.

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Spherical Zirconia Particles Via Electrostatic Atomization: Fabrication and Sintering Characteristics

MRS Proceedings ◽

10.1557/proc-121-257 ◽

1988 ◽

Vol 121 ◽

Cited By ~ 17

Author(s):

E. B. Slamovich ◽

F. F. Lange

Keyword(s):

Electric Field ◽

Single Crystals ◽

Size Distribution ◽

The Other ◽

Sintering Behavior ◽

Space Vehicles ◽

Electrostatic Atomization ◽

Zirconium Acetate ◽

Micron Size ◽

Sintering Characteristics

From the first recorded investigations by Bosetti in 1745 through G.I. Taylor's[2] work on the “Disintegration of Water Droplets in an Electric Field” in 1964, electrostatic atomization of liquids has been put to use in a variety of applications ranging from crop spraying to the propulsion of space vehicles. Here, we have used electrostatic atomization to form micron size droplets of zirconium acetate which pyrolyze to spherical ZrO2 particles for use in sintering studies. Two ZrO2 powders were fabricated. Both are spherical and of similar size distribution, however, in one, the particles are single crystals, while in the other, the particles are polycrystalline. This work discusses the processing of these different particles, and the relative sintering behavior of powders that are composed of either monocrystalline or polycrystalline particles.

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Qualitative analysis of the minimum flow rate of a cone-jet of a very polar liquid

Journal of Fluid Mechanics ◽

10.1017/jfm.2017.111 ◽

2017 ◽

Vol 816 ◽

pp. 428-441 ◽

Cited By ~ 12

Author(s):

F. J. Higuera

Keyword(s):

Electric Field ◽

Flow Rate ◽

Scaling Laws ◽

Shear Stresses ◽

Minimum Flow ◽

Electrostatic Atomization ◽

Finite Electrical Conductivity ◽

Order Of Magnitude ◽

Induced Flow ◽

Minimum Flow Rate

Electrostatic atomization of a liquid of finite electrical conductivity in the so-called cone-jet regime relies on the electric shear stresses that appear in a region of the liquid surface when a meniscus of the liquid is subjected to an intense electric field. An order of magnitude analysis is used to describe the flow induced by these stresses, which drive the liquid of the meniscus into a jet that issues from the tip of the meniscus and breaks into droplets at some distance from it. When the dielectric constant of the liquid is large, the electric shear stresses extend into the jet and cause a depression that sucks liquid from the meniscus. The induced flow rate is estimated and shown to represent approximately the minimum flow rate at which a cone-jet can be established. It is argued that the meniscus can be stabilized by the electric field that the charge of the jet induces on it. This stabilizing mechanism weakens when the flow rate supplied to the meniscus decreases, and its failure may determine an alternative minimum flow rate for the cone-jet regime. The instability of the jet and existing scaling laws for the size of the spray droplets are discussed.

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Resolution in photoelectron microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100086593 ◽

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.

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Field-assisted ionization theory for microscopists

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100171833 ◽

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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