Experimental Study of the Influence of an Electric Field on the Shape of a Droplet PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Experimental Study of the Influence of an Electric Field on the Shape of a Droplet PDF full book. Access full book title Experimental Study of the Influence of an Electric Field on the Shape of a Droplet by Núria Romero Herreros. Download full books in PDF and EPUB format.
Author: Núria Romero Herreros Publisher: ISBN: Category : Languages : en Pages :
Book Description
The electrowetting effect has emerged as an important research topic in recent years. Manipulation of droplets by electric fields has been extensively studied employing different setups, the most common being the configuration in which the electric field is created inside the droplet. However, such a configuration has been mostly employed using conductive liquids, whereas non-conductive droplets have been barely tested under the effect of an electric field using this setup. On the other hand, the influence of an electric field on the shape of a droplet has also been of considerable interest using an alternative configuration in which the electric field is applied between two electrodes with no contact with the drop – the Taylor cone configuration. However, the effects observed employing this last setup are rather different to those obtained using the aforementioned design. While the most important effect in those experiments in which the electric field is created inside the drop is the reduction of the contact angle, the main effect found using the second configuration is the droplet elongation in the electric field direction. In order to demonstrate if dielectric and almost perfectly wetting liquid droplets are affected in the same way as other fluids already tested, the effect of an electric field on the shape of an HFE-7500 droplet has been examined under two different experimental setups by means of interferometric techniques. For the setup where the internal electric field is created, no statistically relevant reduction was measured. Nevertheless, shape deviations have been found at a certain distance of the wire through which the electric field is applied. Moreover, the existence of such deviations depends strongly on the AC frequency. Regarding the second design, it should be mentioned that the initial parallel plate design was working correctly for water+salt droplets. However, no remarkable effects were observed applying strong electric fields of up to 10 kV/cm on HFE-7500 droplets. With the goal of increasing the field strength, two improvised configurations of a metal ring and a needle as a counter-electrodes have also been implemented. In these cases, a strong non-uniform electric field was created which did lead to shape changes of the droplets.
Author: Núria Romero Herreros Publisher: ISBN: Category : Languages : en Pages :
Book Description
The electrowetting effect has emerged as an important research topic in recent years. Manipulation of droplets by electric fields has been extensively studied employing different setups, the most common being the configuration in which the electric field is created inside the droplet. However, such a configuration has been mostly employed using conductive liquids, whereas non-conductive droplets have been barely tested under the effect of an electric field using this setup. On the other hand, the influence of an electric field on the shape of a droplet has also been of considerable interest using an alternative configuration in which the electric field is applied between two electrodes with no contact with the drop – the Taylor cone configuration. However, the effects observed employing this last setup are rather different to those obtained using the aforementioned design. While the most important effect in those experiments in which the electric field is created inside the drop is the reduction of the contact angle, the main effect found using the second configuration is the droplet elongation in the electric field direction. In order to demonstrate if dielectric and almost perfectly wetting liquid droplets are affected in the same way as other fluids already tested, the effect of an electric field on the shape of an HFE-7500 droplet has been examined under two different experimental setups by means of interferometric techniques. For the setup where the internal electric field is created, no statistically relevant reduction was measured. Nevertheless, shape deviations have been found at a certain distance of the wire through which the electric field is applied. Moreover, the existence of such deviations depends strongly on the AC frequency. Regarding the second design, it should be mentioned that the initial parallel plate design was working correctly for water+salt droplets. However, no remarkable effects were observed applying strong electric fields of up to 10 kV/cm on HFE-7500 droplets. With the goal of increasing the field strength, two improvised configurations of a metal ring and a needle as a counter-electrodes have also been implemented. In these cases, a strong non-uniform electric field was created which did lead to shape changes of the droplets.
Author: Suvanjan Bhattacharyya Publisher: Springer Nature ISBN: 9811970556 Category : Technology & Engineering Languages : en Pages : 479
Book Description
This book presents the select proceedings of the 48th National Conference on Fluid Mechanics and Fluid Power (FMFP 2021) held at BITS Pilani in December 2021. It covers the topics such as fluid mechanics, measurement techniques in fluid flows, computational fluid dynamics, instability, transition and turbulence, fluid‐structure interaction, multiphase flows, micro- and nanoscale transport, bio-fluid mechanics, aerodynamics, turbomachinery, propulsion and power. The book will be useful for researchers and professionals interested in the broad field of mechanics.
Author: Arash Bateni Publisher: Library and Archives Canada = Bibliothèque et Archives Canada ISBN: 9780494028384 Category : Languages : en Pages : 480
Book Description
Understanding the influence of an electric field on surface properties of liquids is of importance from both fundamental and practical standpoints. Charged or electrified drops currently play a key role in various applications, ranging from microfluidic devices to agricultural treatments. Nevertheless, the effects of the electric field on surface properties of drops are not understood yet, mainly due to the lack of reliable tools and methodologies to measure such effects.In this research, novel methodologies are developed that allow study of shape, surface tension, and contact angle of drops in the electric field: Automated Polynomial Fitting (APF) is a high-accuracy technique to determine contact angle of drops. It is applicable quite universally, and hence can be employed to measure the effect of the electric field on contact angles. Axisymmetric Drop Shape Analysis-Electric Fields (ADSA-EF) is a sophisticated drop-shape shape technique developed to study surface tension of drops in the electric field. ADSA-EF can also measure surface tensions in the absence of gravity; hence it is an ideal tool for microgravity research. Axisymmetric Liquid Fluid Interface-Electric Fields (ALFI-EF) is a side product of this research that can predict and simulate drop shapes in the electric field.In addition, two sets of ADSA-EF experiments were conducted in reduced-gravity using facilities provided by the Canadian Space Agency (CSA). In general, the measurements in the reduced-gravity condition agreed well with the previous ground-based measurements. The results suggested that gravity has no significant influence on the surface tension, as expected.Extensive experimental work was performed using the new methodologies. The correlation between thermodynamic contact angles and the electric field was determined for the first time, using APF. It was found that contact angle of polar liquids increases in the electric field (depending on the size of the molecules), whereas non-polar liquids remain unaffected by the field. The observations were interpreted in terms of liquid interfacial tensions, using thermodynamic relations. ADSA-EF experiments showed similar increase in liquid surface tensions; furthermore, they revealed a second-order correlation between the surface tension of conducting liquids and the electric field.
Author: Alireza Karbalaei Baba Publisher: ISBN: Category : Languages : en Pages : 106
Book Description
Passive and electrically active coalescence and mixing of pairs of trapped squeezed nanodroplets were studied in this work. PDMS-glass microfluidic devices were designed and fabricated using multilevel photolithography technique. Flow-focusing method was used to generate nanoliter droplets of died glycerol inside oleic acid. The effect of factors such as flow rates and their ratio, interfacial tension, and viscosities on the size and frequency of droplet generation was studied and concluded by demonstrating the capillary number effect. A passive droplet trapping technique based on minimizing the surface energy of the droplets was employed to minimize the shear flow effects and increase the accuracy of passive coalescence and mixing experiments. The theoretical platform was presented for the analysis of this multiphase problem and a numerical solver was developed based on the lattice Boltzmann method to simulate the passive and electro-coalescence of the droplet pairs. Mixing of nanodroplets was studied by discussing the contributing mixing time scales and passive mixing of glycerol nanodroplets was experimentally realized. The rate of passive mixing percentage was derived by performing image processing and its exponential asymptotical behavior was presented. This study provided physical perspectives for droplet coalescence and mixing and can be extended in several numerical and experimental aspects.
Author: Eric Brouzes Publisher: MDPI ISBN: 3036501843 Category : Science Languages : en Pages : 114
Book Description
Droplet microfluidics has dramatically developed in the past decade and has been established as a microfluidic technology that can translate into commercial products. Its rapid development and adoption have relied not only on an efficient stabilizing system (oil and surfactant), but also on a library of modules that can manipulate droplets at a high-throughput. Droplet microfluidics is a vibrant field that keeps evolving, with advances that span technology development and applications. Recent examples include innovative methods to generate droplets, to perform single-cell encapsulation, magnetic extraction, or sorting at an even higher throughput. The trend consists of improving parameters such as robustness, throughput, or ease of use. These developments rely on a firm understanding of the physics and chemistry involved in hydrodynamic flow at a small scale. Finally, droplet microfluidics has played a pivotal role in biological applications, such as single-cell genomics or high-throughput microbial screening, and chemical applications. This Special Issue will showcase all aspects of the exciting field of droplet microfluidics, including, but not limited to, technology development, applications, and open-source systems.
Author: H.R. Pruppacher Publisher: Springer Science & Business Media ISBN: 0306481006 Category : Science Languages : en Pages : 975
Book Description
Cloud physics has achieved such a voluminous literature over the past few decades that a significant quantitative study of the entire field would prove unwieldy. This book concentrates on one major aspect: cloud microphysics, which involves the processes that lead to the formation of individual cloud and precipitation particles. Common practice has shown that one may distinguish among the following addi tional major aspects: cloud dynamics, which is concerned with the physics respon sible for the macroscopic features of clouds; cloud electricity, which deals with the electrical structure of clouds and the electrification processes of cloud and precipi tation particles; and cloud optics and radar meteorology, which describe the effects of electromagnetic waves interacting with clouds and precipitation. Another field intimately related to cloud physics is atmospheric chemistry, which involves the chemical composition ofthe atmosphere and the life cycle and characteristics of its gaseous and particulate constituents. In view of the natural interdependence of the various aspects of cloud physics, the subject of microphysics cannot be discussed very meaningfully out of context. Therefore, we have found it necessary to touch briefly upon a few simple and basic concepts of cloud dynamics and thermodynamics, and to provide an account of the major characteristics of atmospheric aerosol particles. We have also included a separate chapter on some of the effects of electric fields and charges on the precipitation-forming processes.
Author: Núria Romero Herreros
Author: Núria Romero Herreros
Author: Suvanjan Bhattacharyya![Development of New Methodologies for the Study of Surface Tension and Contact Angle of Drops in an Electric Field [microform] PDF](https://books.google.com/books/content/images/frontcover/ZtibtgAACAAJ?fife=w80-h100)
Author: Arash Bateni
Author: Alireza Karbalaei Baba
Author: 
Author: Eric Brouzes
Author: 
Author: 
Author: H.R. Pruppacher
Author: