Download or read book Theoretical Study of Drop Impact on Structured Surfaces written by Soseh Zadoorian and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Droplet impact on superhydrophobic surfaces has been studied extensively due to its abundance and importance in natural and industrial phenomena. As superhydrophobic surfaces may lose their superhydrophobicity due to droplet impact in many applications, the robustness of the superhydrophobic surfaces is important. The superhydrophobicity of a surface is characterized by the surface chemistry and roughness. The liquid on a rough surface forms a liquid-air interface due to the existence of air inside the surface cavities. To have a robust superhydrophobic surface, the liquid should not wet the entire surface cavities, but only the top of surface asperities. Thus, the liquid will be supported by a liquid-solid and a liquid-air interface. Liquid penetration into the air cavities will lead to an irreversible transition. To prevent this wetting transition, a design criterion for regularly patterned rough surfaces is established based on a pressure balance on the liquid-air interface. The effective pressure terms on the liquid-air interface for an impacting droplet condition are introduced first. To avoid liquid penetration, the wetting pressure, which is the Water-hammer pressure, must be smaller than the non-wetting pressure, which is the Laplace pressure. In this work, these two pressure terms are modified for rough structured surfaces. The Water-hammer pressure for structured surfaces is derived based on two different approaches, the impacting droplet model and the electrical circuit model. According to the derived equation for the Water-hammer pressure on structured surfaces, a correlation for the water-hammer coefficient is introduced for structured surfaces. The Laplace pressure on structured surfaces is modified based on two simplifying assumptions for the shape of the liquid-air interface. A spherical cap shape is assumed for the liquid-air interface and a sagging wetting transition mechanism is considered.It is shown that both pressure terms can be derived as a function of surface structures. Thus the pressure balance results in a design criterion for the surface structures. In addition to the pressure balance, another design criterion is presented based on the limiting penetration depth for the liquid-air interface inside the surface cavities at the moment of impact." --
Download or read book Imaging and Analysis of Water Drop Impacts on Microstructured Surfaces written by Matheu Alec James Broom and published by . This book was released on 2020 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Thesis describes the study of water drop impacts on microstructured surfaces. Previous studies of liquid droplets impacting on solid surfaces have mostly been concerned with smooth flat surfaces. The introduction of an array of micrometre-scale pillars (microstructure) adds new research avenues. This work systematically studies the effect of the microstructure design on droplet impact phenomena. The experiments in this study include over 800 high speed videos of water drop impacts on 23 different surface designs. Droplets with an average diameter D0 = 2.51 ± 0.04 mm are produced with 11 discrete impact velocities in the range of 1.5 - 2.5 m/s producing a range of impact Weber numbers (We) from 50 to 250. Soft-lithography methods are used for the production of polydimethylsiloxane (PDMS) surfaces. The microstructures consist of 20 μm width pillars of both circular and square cross sectional shape arranged in square arrays. A selection of pillar spacings (40 μm, 60 μm and 80 μm) and pillar heights (15 μm, 22 μm and 30 μm) is investigated. The creation of a dual view time-synchronized high-speed imaging system is demonstrated. Using this system, drop impact events can be recorded at frame rates between 10,000 and 42,000 frames per second (fps), with an exposure time between 10 μs and 2 μs. High magnification optics produce a spatial resolution range of ± 20 μm to ± 4 μm. A Matlab image processing script is created for the automatic extraction of data during real time (25 fps) playback. These methods are first employed to study phenomena that are observed promptly after the impact event (
Download or read book Analysis of Droplet Impact Onto Horizontal and Inclined Surfaces written by Šefko Šikalo and published by . This book was released on 2003 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Theoretical Aspects of Droplet Impact Measurements written by Ross D. Brazee and published by . This book was released on 1963 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Drop Surface Interactions written by Martin Rein and published by Springer. This book was released on 2014-05-04 with total page 317 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a comprehensive overview of fluid mechanical, thermal and physico-chemical aspects of drop-surface interactions. Basic physical mechanisms pertaining to free-surface flow phenomena characteristic of drop impact on solid and liquid surfaces are explained emphasizing the importance of scaling. Moreover, physico-chemical fundamentals relating to a forced spreading of complex solutions, analytical tools for calculating compressibility effects, and heat transfer and phase change phenomena occurring during solidification and evaporation processes, respectively, are introduced in detail. Finally, numerical approaches particularly suited for modeling drop-surface interactions are consisely surveyed with a particular emphasis on boundary integral methods and Navier-Stokes algorithms (volume of fluid, level set and front tracking algorithms). The book is closed by contributions to a workshop on Drop-Surface Interactions held at the International Centre of Mechanical Sciences.
Download or read book Superhydrophobic Surfaces written by Russell J. Crawford and published by Elsevier. This book was released on 2015-02-19 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: Superhydrophobic Surfaces analyzes the fundamental concepts of superhydrophobicity and gives insight into the design of superhydrophobic surfaces. The book serves as a reference for the manufacturing of materials with superior water-repellency, self-cleaning, anti-icing and corrosion resistance. It thoroughly discusses many types of hydrophobic surfaces such as natural superhydrophobic surfaces, superhydrophobic polymers, metallic superhydrophobic surfaces, biological interfaces, and advanced/hybrid superhydrophobic surfaces. - Provides an adequate blend of complex engineering concepts with in-depth explanations of biological principles guiding the advancement of these technologies - Describes complex ideas in simple scientific language, avoiding overcomplicated equations and discipline-specific jargon - Includes practical information for manufacturing superhydrophobic surfaces - Written by experts with complementary skills and diverse scientific backgrounds in engineering, microbiology and surface sciences
Download or read book The Surface Wettability Effect on Phase Change written by Marco Marengo and published by Springer Nature. This book was released on 2021-10-30 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Surface Wettability Effect on Phase Change collects high level contributions from internationally recognised scientists in the field. It thoroughly explores surface wettability, with topics spanning from the physics of phase change, physics of nucleation, mesoscale modeling, analysis of phenomena such drop evaporation, boiling, local heat flux at triple line, Leidenfrost, dropwise condensation, heat transfer enhancement, freezing, icing. All the topics are treated by discussing experimental results, mathematical modeling and numerical simulations. In particular, the numerical methods look at direct numerical simulations in the framework of VOF simulations, phase-field simulations and molecular dynamics. An introduction to equilibrium and non-equilibrium thermodynamics of phase change, wetting phenomena, liquid interfaces, numerical simulation of wetting phenomena and phase change is offered for readers who are less familiar in the field. This book will be of interest to researchers, academics, engineers, and postgraduate students working in the area of thermofluids, thermal management, and surface technology.
Download or read book Drop Surface Interactions written by Martin Rein and published by Springer Science & Business Media. This book was released on 2002-10-30 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a comprehensive overview of fluid mechanical, thermal and physico-chemical aspects of drop-surface interactions. Basic physical mechanisms pertaining to free-surface flow phenomena characteristic of drop impact on solid and liquid surfaces are explained emphasizing the importance of scaling. Moreover, physico-chemical fundamentals relating to a forced spreading of complex solutions, analytical tools for calculating compressibility effects, and heat transfer and phase change phenomena occurring during solidification and evaporation processes, respectively, are introduced in detail. Finally, numerical approaches particularly suited for modeling drop-surface interactions are consisely surveyed with a particular emphasis on boundary integral methods and Navier-Stokes algorithms (volume of fluid, level set and front tracking algorithms). The book is closed by contributions to a workshop on Drop-Surface Interactions held at the International Centre of Mechanical Sciences.
Download or read book Drop Impact on an Inclined and a Moving Surface written by Salman Buksh Sookran and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis has made progress in two different areas related to drop impact onto a surface. Firstly, a systematic experimental study has been performed to understand asymmetric spreading of low and high surface tension liquids on a moving surface. A new time evolution model for droplet spreading on a moving surface was developed. This model regardless the value of surface tension of the liquid can predict the spreading of low viscous (1-4cSt) liquids on a moving surface. Secondly, liquids with viscosity (1-5cSt) and surface tension (17.4-72.8mNm) were used to study the drop impact on moving and inclined surface. Experiments performed with similar normal (0.9-2.9m/s) and tangential (0.8-2.9m/s) velocities on both surfaces to test our hypothesis that spreading/splashing for these two surface conditions should be same. Results indicates that our hypothesis is true, except for some special conditions when, normal and tangential velocities are greater than the range of our analysis.
Download or read book Investigation of Free surface Flow Associated with Drop Impact written by Edin Berberović and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Droplet Wetting and Evaporation written by David Brutin and published by Academic Press. This book was released on 2015-05-11 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: Droplet Wetting and Evaporation provides engineers, students, and researchers with the first comprehensive guide to the theory and applications of droplet wetting and evaporation. Beginning with a relevant theoretical background, the book moves on to consider specific aspects, including heat transfer, flow instabilities, and the drying of complex fluid droplets. Each chapter covers the principles of the subject, addressing corresponding practical issues and problems. The text is ideal for a broad range of domains, from aerospace and materials, to biomedical applications, comprehensively relaying the challenges and approaches from the different communities leading the way in droplet research and development. - Provides a broad, cross-subject coverage of theory and application that is ideal for engineers, students and researchers who need to follow all major developments in this interdisciplinary field - Includes comprehensive discussions of heat transfer, flow instabilities, and the drying of complex fluid droplets - Begins with an accessible summary of fundamental theory before moving on to specific areas such as heat transfer, flow instabilities, and the drying of complex fluid droplets
Download or read book Contact Angle Wettability and Adhesion Volume 6 written by Kash L. Mittal and published by CRC Press. This book was released on 2009-09-30 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt: The topic of wettability (measured in terms of contact angle) is of tremendous interest from both fundamental and applied points of view, Wettability plays an essential role in many industrial processes, so an understanding of factors dictating wettability and how to modulate it is of paramount importance. In the last years there has been an explos
Download or read book Collision Phenomena in Liquids and Solids written by Alexander L. Yarin and published by Cambridge University Press. This book was released on 2017-06-15 with total page 629 pages. Available in PDF, EPUB and Kindle. Book excerpt: A unique and in-depth discussion uncovering the unifying features of collision phenomena in liquids and solids, along with applications.
Download or read book Droplet Interactions and Spray Processes written by Grazia Lamanna and published by Springer Nature. This book was released on 2020-03-14 with total page 311 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a selection of contributions to the DIPSI workshop 2019 (Droplet Impact Phenomena & Spray Investigations) as well as recent progress of the Int. Research Training Group “DROPIT”.The DIPSI workshop, which is now at its thirteenth edition, represents an important opportunity to share recent knowledge on droplets and sprays in a variety of research fields and industrial applications. The research training group “DROPIT” is focused on droplet interaction technologies where microscopic effects influence strongly macroscopic behavior. This requires the inclusion of interface kinetics and/or a detailed analysis of surface microstructures. Normally, complicated technical processes cover the underlying basic mechanisms, and therefore, progress in the overall process modelling can hardly be gained. Therefore, DROPIT focuses on the underlying basic processes. This is done by investigating different spatial and/or temporal scales of the problems and by linking them through a multi-scale approach. In addition, multi-physics are required to understand e.g. problems for droplet-wall interactions, where porous structures are involved.
Download or read book Capillarity and Wetting Phenomena written by Pierre-Gilles de Gennes and published by Springer Science & Business Media. This book was released on 2013-03-20 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of capillarity is in the midst of a veritable explosion. What is offered here is not a comprehensive review of the latest research but rather a compendium of principles designed for the undergraduate student and for readers interested in the physics underlying these phenomena.
Download or read book Materials Engineering and Technologies for Production and Processing IV written by Andrey A. Radionov and published by Trans Tech Publications Ltd. This book was released on 2018-10-01 with total page 1444 pages. Available in PDF, EPUB and Kindle. Book excerpt: The presented volume contains the scientific articles selected by results of the 4th International Conference on Industrial Engineering (4th ICIE, May 15-18, 2018, Moscow, Russian Federation) which reflect the current achievements in area of materials science, metallurgy, metalworking technologies, polymers, composite materials, ceramics, building materials and chemical technologies. We hope that this collection will be useful and interesting for engineers and researchers from mentioned branches of the engineering science.
