scholarly journals Visualization of Electrohydrodynamic Fluid Motion under Dielectric Liquid Surface Exposed with Corona Discharge by means of Schlieren Photographs

1999 ◽  
Vol 19 (Supplement1) ◽  
pp. 125-128 ◽  
Author(s):  
Kosuke Inoue ◽  
Ryu-ichiro Ohyama
Keyword(s):  
Corona Discharge ◽  
Liquid Surface ◽  
Fluid Motion ◽  
Dielectric Liquid

scholarly journals Tunable-Focus Liquid Lens through Charge Injection

Micromachines ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 109 ◽  
Author(s):  
Shizhi Qian ◽  
Wenxiang Shi ◽  
Huai Zheng ◽  
Zhaohui Liu
Keyword(s):  
Corona Discharge ◽  
Charge Injection ◽  
Dielectric Liquid ◽  
Liquid Lenses ◽  
Liquid Lens ◽  
3D Printed ◽  
Tube Structure

Liquid lenses are the simplest and cheapest optical lenses, and various studies have been conducted to develop tunable-focus liquid lenses. In this study, a simple and easily implemented method for achieving tunable-focus liquid lenses was proposed and experimentally validated. In this method, charges induced by a corona discharge in the air were injected into dielectric liquid, resulting in “electropressure” at the interface between the air and the liquid. Through a 3D-printed U-tube structure, a tunable-focus liquid lens was fabricated and tested. Depending on the voltage, the focus of the liquid lens can be adjusted in large ranges (−∞ to −9 mm and 13.11 mm to ∞). The results will inspire various new liquid-lens applications.

On the corona discharge spreading of dielectric liquid films

2013 ◽  
Vol 71 (3) ◽  
pp. 496-498 ◽  
Author(s):  
S.R. Mahmoudi ◽  
K. Adamiak ◽  
G.S.P. Castle
Keyword(s):  
Corona Discharge ◽  
Liquid Films ◽  
Dielectric Liquid

The spreading of surfactant-laden liquids with surfactant transfer through the contact line

2001 ◽  
Vol 440 ◽  
pp. 205-234 ◽  
Author(s):  
ENRIQUE RAMÉ
Keyword(s):  
Contact Line ◽  
Liquid Surface ◽  
Fluid Motion ◽  
Dynamic Contact ◽  
Contact Angles ◽  
Moving Contact Line ◽  
Surface Diffusivity ◽  
Moving Contact ◽  
Pure Fluid ◽  
Surfactant Transfer

We examine the spreading of a liquid on a solid surface when the liquid surface has a spread monolayer of insoluble surfactant, and the surfactant transfers through the contact line between the liquid surface and the solid. We show that, as in surfactant-free systems, a singularity appears at the moving contact line. However, unlike surfactant-free systems, the singularity cannot be removed by the same assumptions as long as surfactant transfer takes place. In an attempt to avoid modelling difficulties posed by the question of how the singularity might be removed, we identify parameters which describe the dynamics of the macroscopic spreading process. These parameters, which depend on the details of the fluid motion next to the contact line as in the pure-fluid case, also depend on the state of the spread surfactant in the macroscopic region, in sharp contrast to the pure-fluid case where actions at the macroscopic scale did not affect material spreading parameters. A model of the viscous-controlled region near the contact line which accounts for surfactant transfer shows that, at steady state, some ranges of dynamic contact angles and of capillary number are forbidden. For a given surfactant–liquid pair, these disallowed ranges depend upon the actual contact angle and on the transfer flux of surfactant.We also examine a possible inner model which accounts for the transfer via surface diffusivity and regularizes the stress via a slip model. We show that the asymptotic behaviour of this model at distances from the contact line large compared to the inner length scale matches to the viscous-controlled region. An example of how the information propagates is given.

scholarly journals Generation and Transport of Dielectric Droplets along Microchannels by Corona Discharge

Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 181
Author(s):  
Qiang Tang ◽  
Shangru Zhou ◽  
Ruiheng Hu ◽  
Huai Zheng ◽  
Junheng Pan ◽  
...  
Keyword(s):  
Corona Discharge ◽  
Simple Approach ◽  
Dielectric Liquid ◽  
Dielectric Fluid ◽  
Spreading Speeds

In this paper, a phenomenon of generation and transport of droplets is proposed, which is based on the dielectric liquid electroconvection induced by corona discharge. We placed the dielectric fluid on a conductive/nonconductive substrate, and then it broke apart to become many small droplets that move along the conductive microchannel. The behaviors of dielectric droplets were experimentally observed on different conductive microchannels in details. Spreading speeds and sizes of dielectric droplets were analyzed at different driving voltages and conductive microchannels. This work highlights a simple approach to produce and manipulate dielectric droplets along microchannels.

scholarly journals Studying the surfactant dynamics at non-isothermal liquid surface with thermography

2021 ◽  
Vol 2127 (1) ◽  
pp. 012003
Author(s):  
A I Mizev ◽  
A V Shmyrov
Keyword(s):  
Stagnation Point ◽  
Liquid Surface ◽  
Fluid Motion ◽  
Adsorbed Layer ◽  
Theoretical Models ◽  
Thermocapillary Effect ◽  
New Approach ◽  
Numerical Studies ◽  
Multiphase Systems ◽  
Pure Surface

Abstract The dynamics of liquid multiphase systems largely depends on the conditions on the interface. The behavior of a system with adsorbed surfactant layers at the interface boundaries may differ qualitatively from the behavior of a system with pure surface. The experimental study of such systems is difficult, since the presence of adsorbed layer can most often be judged only by indirect signs. Therefore, most of the research is carried out by numerical modeling. Unfortunately, the currently existing numerical studies of liquid multiphase systems with adsorbed surfactant layer are far from perfect due to numerous simplifications and approximations assumed in theoretical models. In this paper, we propose a new approach for visualization and studying the boundary between a clean surface and an adsorbed surfactant layer. It is based on the comparison of track images of the fluid motion in the volume and the registration of the temperature distribution at the interface boundary. This approach made it possible to unambiguously associate the characteristic regions on the temperature profile with the position of the so-called stagnation point. The proposed method for visualizing the stagnation point can be useful in a number of problems of interface hydrodynamics based on the thermocapillary effect.

Electrohydrodynamic peculiarities of corona discharge interaction with a liquid surface

2011 ◽  
Vol 66 (4) ◽  
pp. 390-397 ◽  
Author(s):  
A. F. Aleksandrov ◽  
V. L. Bychkov ◽  
D. V. Bychkov ◽  
S. A. Volkov ◽  
A. A. Kostyuk ◽  
...  
Keyword(s):  
Corona Discharge ◽  
Liquid Surface
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