Shape evolution of compound droplet in combined presence of electric field and extensional flow

2020 ◽  
Vol 5 (6) ◽  
Author(s):  
Somnath Santra ◽  
Devi Prasad Panigrahi ◽  
Sayan Das ◽  
Suman Chakraborty
Keyword(s):  
Electric Field ◽  
Extensional Flow ◽  
Shape Evolution ◽  
Compound Droplet

Dynamics of a compound droplet under the combined influence of electric field and shear flow

2021 ◽  
Vol 6 (2) ◽  
Author(s):  
Manash Pratim Borthakur ◽  
Binita Nath ◽  
Gautam Biswas
Keyword(s):  
Shear Flow ◽  
Electric Field ◽  
Compound Droplet

Compound‐Droplet‐Pairs‐Filled Hydrogel Microfiber for Electric‐Field‐Induced Selective Release

Small ◽  
2019 ◽  
Vol 15 (42) ◽  
pp. 1903098 ◽  
Author(s):  
Xiaokang Deng ◽  
Yukun Ren ◽  
Likai Hou ◽  
Weiyu Liu ◽  
Tianyi Jiang ◽  
...  
Keyword(s):  
Electric Field ◽  
Compound Droplet

Evolution of a compound droplet attached to a core-shell nozzle under the action of a strong electric field

2006 ◽  
Vol 18 (6) ◽  
pp. 062101 ◽  
Author(s):  
S. N. Reznik ◽  
A. L. Yarin ◽  
E. Zussman ◽  
L. Bercovici
Keyword(s):  
Electric Field ◽  
Strong Electric Field ◽  
Core Shell ◽  
Compound Droplet

scholarly journals Electric field-induced pinch-off of a compound droplet in Poiseuille flow

2019 ◽  
Vol 31 (6) ◽  
pp. 062004 ◽  
Author(s):  
Somnath Santra ◽  
Sayan Das ◽  
Suman Chakraborty
Keyword(s):  
Electric Field ◽  
Poiseuille Flow ◽  
Compound Droplet

Extensional flow of nematic liquid crystal with an applied electric field

2013 ◽  
Vol 25 (4) ◽  
pp. 397-423
Author(s):  
L. J. CUMMINGS ◽  
J. LOW ◽  
T. G. MYERS
Keyword(s):  
Liquid Crystal ◽  
Electric Field ◽  
Nematic Liquid Crystal ◽  
Asymptotic Methods ◽  
Thin Sheet ◽  
Extensional Flow ◽  
Full Model ◽  
Trouton Ratio ◽  
Newtonian Case ◽  
Model Equations

Systematic asymptotic methods are used to formulate a model for the extensional flow of a thin sheet of nematic liquid crystal. With no external body forces applied, the model is found to be equivalent to the so-called Trouton model for Newtonian sheets (and fibres), albeit with a modified ‘Trouton ratio’. However, with a symmetry-breaking electric field gradient applied, behaviour deviates from the Newtonian case, and the sheet can undergo finite-time breakup if a suitable destabilizing field is applied. Some simple exact solutions are presented to illustrate the results in certain idealized limits, as well as sample numerical results to the full model equations.

scholarly journals A Study of Electric Field Effect on Melting of Octadecane

2016 ◽  
Vol 17 (2) ◽  
pp. 256-261
Author(s):  
S.G. Orlovskaya ◽  
F.F. Karimova ◽  
M.S. Shkoropado
Keyword(s):  
Electric Field ◽  
Melting Rate ◽  
Melting Time ◽  
Electric Field Effect ◽  
Shape Evolution ◽  
Solid Core ◽  
Droplet Shape ◽  
Melting Kinetics ◽  
Calculation Results ◽  
Kinetics Of

A new approach is developed to study melting kinetics of n-Octadecane. Modelling of heat transfer during the melting of solid particle is described. The calculation results are in good agreement with experimental data on melting duration. The effect of applied electric field on melting kinetics is studied. Almost twofold increase of melting time is found in an electric field of strength E = 82 kv/m. In addition a rotation of a solid core inside a melt is observed, which is a manifestation of Quinke effect. A droplet shape evolution during phase transition is described. It is shown that initially elongated particle is almost spherical near the melting point and elongates again with the temperature rise. This shape evolution is explained by non-monotonous change of surface tension and is connected with rotational phase. Thus a possibility is shown to control a melting rate of normal alkanes using electric field.

Image Treatment of a 2D Vapor-Liquid Compound Droplet in a Linearized Steady Viscous Flow

2008 ◽  
Vol 130 (7) ◽  
Author(s):  
D. Palaniappan
Keyword(s):  
Exact Solutions ◽  
Stokes Flow ◽  
Extensional Flow ◽  
Flow Fields ◽  
Uniform Flow ◽  
Creeping Flow ◽  
Physical Parameters ◽  
Vertex Angle ◽  
Compound Droplet ◽  
Vapor Liquid

The classical method of images is used to construct closed form exact solutions for the two-dimensional (2D) perturbed flow fields in the presence of a 2D vapor-liquid compound droplet in the limit of low-Reynolds number. The geometry of the multiphase droplet is composed of two overlapping infinitely long cylinders Ca and Cb of radii a and b, respectively, intersecting at a vertex angle π∕2. The composite inclusion has the shape resembling a 2D snowman type of object with a vapor cylinder Ca partly protruded into the cylinder Cb filled with another fluid whose viscosity is different from that of the host fluid. The mathematical problem with this inclusion in the Stokes flow environment is formulated in terms of Stokes stream function with mixed boundary conditions at the boundary of the hybrid droplet. General expressions for the perturbed stream functions in the two phases are obtained in a straightforward fashion using Kelvin’s inversion together with shift and reflection properties of biharmonic functions. Application of our method to other related problems in creeping flow and possible further generalizations are also discussed. The general results are then exploited to derive singularity solutions for the hybrid droplet embedded in (i) a centered shear flow, (ii) a quadratic potential flow, and (iii) an extensional flow past the 2D vapor-liquid compound droplet. The image singularities in each case depend on the two radii of the cylinders, the center-to-center distance, and the viscosity ratio. The exact solutions are utilized to plot the flow streamlines and they show some interesting patterns. While the flow fields exterior to the droplet exhibit symmetrical topological structures, the interior flow fields show existence of free eddies—enclosed in a figure-eight separatrix—and stagnation points (hyperbolic points). The flow characteristics are influenced by the viscosity and radii ratios. Furthermore, the asymptotic analysis leads to a rather surprising conclusion that there is a (subdominant) uniform flow far away from the droplet in all cases. The existence of an origin, the natural center of the drop of the composite geometry, which neutralizes the uniform flow for a particular choice of the physical parameters, is illustrated. This reveals the sensitivity of the geometry in 2D Stokes flow. The present results may be of some interest in models involving a combination of stick and slip boundaries. Moreover, the method discussed here can be useful both as a teaching tool and as a building block for further calculations.

scholarly journals Influence of the Polarity of the Electric Field on Electrorheometry

2019 ◽  
Vol 9 (24) ◽  
pp. 5273 ◽  
Author(s):  
J. García-Ortiz ◽  
Samir Sadek ◽  
Francisco Galindo-Rosales
Keyword(s):  
Shear Flow ◽  
Electric Field ◽  
Simple Shear ◽  
Flow Direction ◽  
Extensional Flow ◽  
Electrorheological Fluid ◽  
Stable Configuration ◽  
Simple Shear Flow ◽  
Rheological Characterization

Uniaxial extensional flow is a canonical flow typically used in rheological characterization to provide complementary information to that obtained by imposing simple shear flow. In spite of the importance of having a full rheological characterization of complex fluids, publications on the rheological characterization of mobile liquids under extensional flow have increased significantly only in the last 20 years. In the case of the rheological characterization of electrorheological fluids, the situation is even more dramatic, as the ERFs have been exclusively determined under simple shear flow, where an electrorheological cell is attached to the rotational rheometer generating an electric field perpendicular to the flow direction and that does not allow for inverting the polarity. The very recent work published by Sadek et al., who developed a new electrorheological cell to be used with the commercial Capillary Breakup Extensional Rheometer (CaBER), allows for the very first time performing electrorheometry under extensional flow. By means of the same experimental setup, this study investigates the influence of the polarity of the imposed electric field on the filament thinning process of a Newtonian and an electrorheological fluid. Results show that a polarity against the gravity results in filament thinning processes that live longer or reach a stable configuration at lower intensities of the applied electric field.

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.

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