Study Of The Effects Of Surface Morphology And Droplet Growth Dynamics On Condensation Heat Transfer

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Study of the Effects of Surface Morphology and Droplet Growth Dynamics on Condensation Heat Transfer

Author : Chun-Wei Yao
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (92 download)

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Book Synopsis Study of the Effects of Surface Morphology and Droplet Growth Dynamics on Condensation Heat Transfer by : Chun-Wei Yao

Download or read book Study of the Effects of Surface Morphology and Droplet Growth Dynamics on Condensation Heat Transfer written by Chun-Wei Yao and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Condensation heat transfer has recently received a lot of renewed attention due to the development and use of surfaces with micro- and nano-scale features. Most of the new surfaces tend to promote dropwise condensation, which leads to higher rates of heat transfer when compared with filmwise condensation. In the current study, the effects of surface morphology and surface chemistry on the condensation mechanisms have been investigated using engineered surfaces. Firstly, hybrid surfaces consisting of an array of micropillars with hydrophobic and hydrophilic sites have been designed to exhibit a distinct Cassie-Baxter wetting behavior at different temperatures. Characterization experiments have revealed that hybrid surfaces depict a unique wetting behavior. Furthermore, more types of engineered surfaces were fabricated including nanoparticle-based hydrophobic surface, polytetrafluoroethylene (PTFE) surface, and self-assembled monolayers (SAMs) surface. Experiments have been conducted to determine the heat transfer performance of all engineered surfaces under a constant humidity level, surface-to-ambient temperature difference, and laminar flow conditions. Experimental results reveal that droplet sliding can have an important effect on heat transfer performance. Also, empirical heat transfer correlations have been postulated and fitted using experimental data using condensing and air temperature difference and Reynolds number as independent variables. Results indicate that the postulated correlations are in excellent agreement with experimental data. In addition, surface temperature data obtained using an advanced IR imaging system have been analyzed to determine the effects of the surface features on droplet growth dynamics. The non-invasive IR measurement technique has been helpful in understanding the droplet growth dynamics such as droplet coalescence. Results to date show that the static contact angles and sliding angles have marked effects on droplet growth and coalescence on the surfaces in the early stages of condensation. Furthermore, results also reveal that droplet sliding angles can have an important effect on droplet sliding motion and condensed droplet dynamics play an important role during the overall condensation process. In summary, the effect of surface morphology and droplet growth dynamics on heat transfer during condensation were investigated and elucidated. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/152590

Drop Dynamics and Dropwise Condensation on Textured Surfaces

Author : Sameer Khandekar
Publisher : Springer Nature
ISBN 13 : 3030484610
Total Pages : 462 pages
Book Rating : 4.0/5 (34 download)

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Book Synopsis Drop Dynamics and Dropwise Condensation on Textured Surfaces by : Sameer Khandekar

Download or read book Drop Dynamics and Dropwise Condensation on Textured Surfaces written by Sameer Khandekar and published by Springer Nature. This book was released on 2020-09-11 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is an expanded form of the monograph, Dropwise Condensation on Inclined Textured Surfaces, Springer, 2013, published earlier by the authors, wherein a mathematical model for dropwise condensation of pure vapor over inclined textured surfaces was presented, followed by simulations and comparison with experiments. The model factored in several details of the overall quasi-cyclic process but approximated those at the scale of individual drops. In the last five years, drop level dynamics over hydrophobic surfaces have been extensively studied. These results can now be incorporated in the dropwise condensation model. Dropwise condensation is an efficient route to heat transfer and is often encountered in major power generation applications. Drops are also formed during condensation in distillation devices that work with diverse fluids ranging from water to liquid metals. Design of such equipment requires careful understanding of the condensation cycle, starting from the birth of nuclei, followed by molecular clusters, direct growth of droplets, their coalescence, all the way to instability and fall-off of condensed drops. The model described here considers these individual steps of the condensation cycle. Additional discussions include drop shape determination under static conditions, a fundamental study of drop spreading in sessile and pendant configurations, and the details of the drop coalescence phenomena. These are subsequently incorporated in the condensation model and their consequences are examined. As the mathematical model is spread over multiple scales of length and time, a parallelization approach to simulation is presented. Special topics include three-phase contact line modeling, surface preparation techniques, fundamentals of evaporation and evaporation rates of a single liquid drop, and measurement of heat transfer coefficient during large-scale condensation of water vapor. We hope that this significantly expanded text meets the expectations of design engineers, analysts, and researchers working in areas related to phase-change phenomena and heat transfer.

Parametric Studies on Dropwise Condensation Heat Transfer

Author : Kuok Kong Cheng
Publisher :
ISBN 13 :
Total Pages : 236 pages
Book Rating : 4.:/5 (928 download)

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Book Synopsis Parametric Studies on Dropwise Condensation Heat Transfer by : Kuok Kong Cheng

Download or read book Parametric Studies on Dropwise Condensation Heat Transfer written by Kuok Kong Cheng and published by . This book was released on 2014 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wettability of a solid surface with liquids could be tuned based on surface morphologies. This is significant in condensation heat transfer. Condensation is a critical heat transfer mechanism in industrial processes; Dropwise (DWC) and Filmwise (FWC) condensation processes are important and are focus of this study. There are few studies on surface morphology effect on wetting behavior of a solid in relation to condensation heat transfer. We conducted these studies to understand the phenomenon. Condensation heat transfer is affected by condensate droplets properties on the surface. Condensate drop sizes and mobility relationships are important to condensation heat transfer. Droplet sizes and mobility affect population density and condensation heat transfer coefficients directly. The goal of this study is to acquire the fundamental understanding of condensation heat transfer with relation to condensate droplet behavior. In order to achieve this goal, a liquid droplet wetting dynamic model was initially developed for predicting single drop behavior on different surfaces. Heat fluxes were then estimated by combining liquid droplet behavior models and heat transfer model. Condensation experiments were conducted to verify effectiveness of the model. Experimental results coupled with condensation models revealed relationships between wetting behaviors and condensation heat transfer. Contact angle hysteresis (CAH) remains low at both high and low droplet contact angle, i.e. whether the surface is hydrophilic or hydrophobic. CAH increases with degree of wetting, but coating thermal conductance also increases. Details of drop (DWC) and film-wise (FWC) condensation are presented.

The Physics of Dew, Breath Figures and Dropwise Condensation

Author : Daniel Beysens
Publisher : Springer Nature
ISBN 13 : 3030904423
Total Pages : 458 pages
Book Rating : 4.0/5 (39 download)

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Book Synopsis The Physics of Dew, Breath Figures and Dropwise Condensation by : Daniel Beysens

Download or read book The Physics of Dew, Breath Figures and Dropwise Condensation written by Daniel Beysens and published by Springer Nature. This book was released on 2022-01-31 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book, the author focuses on the physics behind dew, breaths figures, and dropwise condensation phenomena to introduce scientists, engineers and students to the many original processes involved in condensation. Consisting of 15 Chapters, 18 Appendices and over 500 references, the reader learns the needed theoretical backgrounds and formulae to understand the complexity of dropwise condensation. Heat and mass transfer, nucleation and growth on various substrates are considered (solid, liquid, plastic, undergoing phase change or micro-patterned substrates). The particular role of thermal or geometrical discontinuities where growth can be enhanced or reduced, dynamical aspects of self-diffusion, problems related to drop collection by gravity and the optics of dropwise condensation are all discussed. Although the content mainly deals with condensation from humid air, it can readily be generalized to condensation of any substance. The specificities of pure vapor condensation (e.g. steam) are also examined. Numerous images are provided within the text to illustrate the physics. This book is meant for those studying or researching dew and dropwise condensation, but also for individuals wishing to develop their knowledge on the subject.

Dropwise Condensation on Inclined Textured Surfaces

Author : Sameer Khandekar
Publisher : Springer Science & Business Media
ISBN 13 : 1461484472
Total Pages : 155 pages
Book Rating : 4.4/5 (614 download)

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Book Synopsis Dropwise Condensation on Inclined Textured Surfaces by : Sameer Khandekar

Download or read book Dropwise Condensation on Inclined Textured Surfaces written by Sameer Khandekar and published by Springer Science & Business Media. This book was released on 2013-09-06 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dropwise Condensation on Textured Surfaces presents a holistic framework for understanding dropwise condensation through mathematical modeling and meaningful experiments. The book presents a review of the subject required to build up models as well as to design experiments. Emphasis is placed on the effect of physical and chemical texturing and their effect on the bulk transport phenomena. Application of the model to metal vapor condensation is of special interest. The unique behavior of liquid metals, with their low Prandtl number and high surface tension, is also discussed. The model predicts instantaneous drop size distribution for a given level of substrate subcooling and derives local as well as spatio-temporally averaged heat transfer rates and wall shear stress.

21st Century Surface Science

Author : Phuong Pham
Publisher : BoD – Books on Demand
ISBN 13 : 1789851998
Total Pages : 295 pages
Book Rating : 4.7/5 (898 download)

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Book Synopsis 21st Century Surface Science by : Phuong Pham

Download or read book 21st Century Surface Science written by Phuong Pham and published by BoD – Books on Demand. This book was released on 2020-11-26 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface sciences elucidate the physical and chemical aspects of the surfaces and interfaces of materials. Of great interest in this field are nanomaterials, which have recently experienced breakthroughs in synthesis and application. As such, this book presents some recent representative achievements in the field of surface science, including synthesis techniques, surface modifications, nanoparticle-based smart coatings, wettability of different surfaces, physics/chemistry characterizations, and growth kinetics of thin films. In addition, the book illustrates some of the important applications related to silicon, CVD graphene, graphene oxide, transition metal dichalcogenides, carbon nanotubes, carbon nanoparticles, transparent conducting oxide, and metal oxides.

Condensational Droplet Growth in Rarefied Quiescent Vapor and Forced Convective Conditions

Author : Sushant Anand
Publisher :
ISBN 13 :
Total Pages : 148 pages
Book Rating : 4.:/5 (777 download)

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Book Synopsis Condensational Droplet Growth in Rarefied Quiescent Vapor and Forced Convective Conditions by : Sushant Anand

Download or read book Condensational Droplet Growth in Rarefied Quiescent Vapor and Forced Convective Conditions written by Sushant Anand and published by . This book was released on 2011 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multiphase Heat transfer is ubiquitous in diverse fields of application such as cooling systems, micro and mini power systems and many chemical processes. By now, single phase dynamics are mostly understood in their applications in vast fields, however multiphase systems especially involving phase changes are still a challenge. Present study aims to enhance understanding in this domain especially in the field of condensation heat transfer. Of special relevance to present studies is study of condensation phenomenon for detection of airborne nanoparticles using heterogeneous nucleation. Detection of particulate matter in the environment via heterogeneous condensation is based on the droplet growth phenomenon where seeding particles in presence of supersaturated vapor undergo condensation on their surface and amplify in size to micrometric ranges, thereby making them optically visible. Previous investigations show that condensation is a molecular exchange process affected by mean free path of vapor molecules ([lambda]) in conjunction with size of condensing droplet (d), which is measured in terms of Knudsen number (Kn=[lambda]/d). In an event involving heterogeneous nucleation with favorable thermodynamic conditions for condensation to take place, the droplet growth process begins with accretion of vapor molecules on a surface through random molecular collision (Kn>1) until diffusive forces start dominating the mass transport process (Kn“1). Knowledge of droplet growth thus requires understanding of mass transport in both of these regimes. Present study aims to understand the dynamics of the Microthermofluidic sensor which has been developed, based on above mentioned fundamentals. Using continuum approach, numerical modeling was carried to understand the effect of various system parameters for improving the device performance to produce conditions which can lead to conditions abetting condensational growth. The study reveals that the minimum size of nanoparticle which can be detected is critically dependent upon controlling wall geometry and size, wall temperature, flow rate and relative humidity of nanoparticle laden air stream. Droplet growths rates and sizes have been predicted based on different models. The efficacy of the device under various conditions has been measured in terms of its ability to activate nanoparticles of different sizes. Since the condensation mechanism is dependent upon the Knudsen regime in which droplets are growing via condensation, special consideration was made to understand their behavior in large Knudsen number conditions. For this purpose, ESEM was used to study condensation on a bare surface. Droplet growth obtained as a function of time reveals that the rate of growth decreases as the droplet increases in size. The experimental results obtained from these experiments were matched with theoretical description provided by a model based on framework of kinetic theory. Evidence was also found which establishes the presence of submicroscopic droplets nucleating and growing in between microscopic droplets for partially wetting case.

Advances in Nanotechnology Research and Application: 2012 Edition

Author :
Publisher : ScholarlyEditions
ISBN 13 : 1464990468
Total Pages : 14170 pages
Book Rating : 4.4/5 (649 download)

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Book Synopsis Advances in Nanotechnology Research and Application: 2012 Edition by :

Download or read book Advances in Nanotechnology Research and Application: 2012 Edition written by and published by ScholarlyEditions. This book was released on 2012-12-26 with total page 14170 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Nanotechnology Research and Application / 2012 Edition is a ScholarlyEditions™ eBook that delivers timely, authoritative, and comprehensive information about Nanotechnology. The editors have built Advances in Nanotechnology Research and Application / 2012 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Nanotechnology in this eBook to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Advances in Nanotechnology Research and Application / 2012 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.

Advances in Heat Transfer

Author :
Publisher : Elsevier
ISBN 13 : 0443193134
Total Pages : 598 pages
Book Rating : 4.4/5 (431 download)

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Book Synopsis Advances in Heat Transfer by :

Download or read book Advances in Heat Transfer written by and published by Elsevier. This book was released on 2023-11-01 with total page 598 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Heat Transfer, Volume 56, presents the latest in a serial that highlights new advances in the field, with this updated volume presenting interesting chapters written by an international board of authors. Provides the authority and expertise of leading contributors from an international board of authors Presents the latest release in Advances in Heat Transfer serials

Ice Adhesion

Author : K. L. Mittal
Publisher : John Wiley & Sons
ISBN 13 : 1119640377
Total Pages : 704 pages
Book Rating : 4.1/5 (196 download)

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Book Synopsis Ice Adhesion by : K. L. Mittal

Download or read book Ice Adhesion written by K. L. Mittal and published by John Wiley & Sons. This book was released on 2020-12-15 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt: This unique book presents ways to mitigate the disastrous effects of snow/ice accumulation and discusses the mechanisms of new coatings deicing technologies. The strategies currently used to combat ice accumulation problems involve chemical, mechanical or electrical approaches. These are expensive and labor intensive, and the use of chemicals raises serious environmental concerns. The availability of truly icephobic surfaces or coatings will be a big boon in preventing the devastating effects of ice accumulation. Currently, there is tremendous interest in harnessing nanotechnology in rendering surfaces icephobic or in devising icephobic surface materials and coatings, and all signals indicate that such interest will continue unabated in the future. As the key issue regarding icephobic materials or coatings is their durability, much effort is being spent in developing surface materials or coatings which can be effective over a long period. With the tremendous activity in this arena, there is strong hope that in the not too distant future, durable surface materials or coatings will come to fruition. This book contains 20 chapters by subject matter experts and is divided into three parts— Part 1: Fundamentals of Ice Formation and Characterization; Part 2: Ice Adhesion and Its Measurement; and Part 3: Methods to Mitigate Ice Adhesion. The topics covered include: factors influencing the formation, adhesion and friction of ice; ice nucleation on solid surfaces; physics of ice nucleation and growth on a surface; condensation frosting; defrosting properties of structured surfaces; relationship between surface free energy and ice adhesion to surfaces; metrology of ice adhesion; test methods for quantifying ice adhesion strength to surfaces; interlaboratory studies of ice adhesion strength; mechanisms of surface icing and deicing technologies; icephobicities of superhydrophobic surfaces; anti-icing using microstructured surfaces; icephobic surfaces: features and challenges; bio-inspired anti-icing surface materials; durability of anti-icing coatings; durability of icephobic coatings; bio-inspired icephobic coatings; protection from ice accretion on aircraft; and numerical modeling and its application to inflight icing.

Surfaces and Interfaces of Biomimetic Superhydrophobic Materials

Author : Zhiguang Guo
Publisher : John Wiley & Sons
ISBN 13 : 3527806709
Total Pages : 402 pages
Book Rating : 4.5/5 (278 download)

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Book Synopsis Surfaces and Interfaces of Biomimetic Superhydrophobic Materials by : Zhiguang Guo

Download or read book Surfaces and Interfaces of Biomimetic Superhydrophobic Materials written by Zhiguang Guo and published by John Wiley & Sons. This book was released on 2017-09-13 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive and systematic treatment that focuses on surfaces and interfaces phenomena inhabited in biomimetic superhydrophobic materials, offering new fundamentals and novel insights. As such, this new book covers the natural surfaces, fundamentals, fabrication methods and exciting applications of superhydrophobic materials, with particular attention paid to the smart surfaces that can show switchable and reversible water wettability under external stimuli, such as pH, temperature, light, solvents, and electric fields. It also includes recent theoretical advances of superhydrophobic surfaces with regard to the wetting process, and some promising breakthroughs to promote this theory. As a result, materials scientists, physicists, physical chemists, chemical engineers, and biochemists will benefit greatly from a deeper understanding of this topic.

Transient Droplet Growth During Dropwise Condensation

Author : Charles Joslin Hurst
Publisher :
ISBN 13 :
Total Pages : 158 pages
Book Rating : 4.:/5 (817 download)

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Book Synopsis Transient Droplet Growth During Dropwise Condensation by : Charles Joslin Hurst

Download or read book Transient Droplet Growth During Dropwise Condensation written by Charles Joslin Hurst and published by . This book was released on 1966 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study investigated the possibility of determining high heat-transfer rates during dropwise condensation by analyzing single condensate droplets growing on a convectively-cooled surface. A mathematical model included both the droplet and a portion of the condensing surface. Experiment utilized condensate droplets, growing on a thin copper surface, to verify the analysis. Experimental results agreed closely with predicted results--indicating high heat-transfer rates at droplet perimeters. Both experiment and analysis showed that no single vapor-to-condensing-surface temperature difference may be expected during dropwise condensation. Limitations on the calculation procedure pertaining to the region around the droplet perimeter restricted the accuracy of heat-transfer rate predictions; a separate study of droplet perimeter is suggested. (Author).

Encyclopedia Of Two-phase Heat Transfer And Flow I: Fundamentals And Methods (A 4-volume Set)

Author : John R Thome
Publisher : World Scientific
ISBN 13 : 9814623229
Total Pages : 1109 pages
Book Rating : 4.8/5 (146 download)

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Book Synopsis Encyclopedia Of Two-phase Heat Transfer And Flow I: Fundamentals And Methods (A 4-volume Set) by : John R Thome

Download or read book Encyclopedia Of Two-phase Heat Transfer And Flow I: Fundamentals And Methods (A 4-volume Set) written by John R Thome and published by World Scientific. This book was released on 2015-08-14 with total page 1109 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of the two-set series is to present a very detailed and up-to-date reference for researchers and practicing engineers in the fields of mechanical, refrigeration, chemical, nuclear and electronics engineering on the important topic of two-phase heat transfer and two-phase flow. The scope of the first set of 4 volumes presents the fundamentals of the two-phase flows and heat transfer mechanisms, and describes in detail the most important prediction methods, while the scope of the second set of 4 volumes presents numerous special topics and numerous applications, also including numerical simulation methods.Practicing engineers will find extensive coverage to applications involving: multi-microchannel evaporator cold plates for electronics cooling, boiling on enhanced tubes and tube bundles, flow pattern based methods for predicting boiling and condensation inside horizontal tubes, pressure drop methods for singularies (U-bends and contractions), boiling in multiport tubes, and boiling and condensation in plate heat exchangers. All of these chapters include the latest methods for predicting not only local heat transfer coefficients but also pressure drops.Professors and students will find this 'Encyclopediaa of Two-Phase Heat Transfer and Flow' particularly exciting, as it contains authored books and thorough state-of-the-art reviews on many basic and special topics, such as numerical modeling of two-phase heat tranfser and adiabatic bubbly and slug flows, the unified annular flow boiling model, flow pattern maps, condensation and boiling theories, new emerging topics, etc.

Dropwise Condensation of Water and Low Surface Tension Fluids on Structured Surfaces

Author : Yajing Zhao (S.M.)
Publisher :
ISBN 13 :
Total Pages : 62 pages
Book Rating : 4.:/5 (15 download)

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Book Synopsis Dropwise Condensation of Water and Low Surface Tension Fluids on Structured Surfaces by : Yajing Zhao (S.M.)

Download or read book Dropwise Condensation of Water and Low Surface Tension Fluids on Structured Surfaces written by Yajing Zhao (S.M.) and published by . This book was released on 2018 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: Condensation is a ubiquitous process often observed in nature and our daily lives. The large amount of latent heat released during the condensation process has been harnessed in many industrial processes such as power generation, building heating and cooling, desalination, dew harvesting, thermal management, and refrigeration. Condensation has two modes: dropwise mode and filmwise mode. Although it has been known for decades that dropwise condensation outperforms filmwise condensation in heat transfer owing to the droplet shedding effects which can efficiently reduce thermal resistance, filmwise condensation still dominates industrial applications currently due to the high costs, low robustness and technical challenges of manufacturing dropwise coatings. During water condensation, dropwise mode can be readily promoted with thin hydrophobic coatings. Superhydrophobic surfaces made out of hydrophobic coatings on micro-or-nano-engineered surfaces have shown further heat transfer enhancement in dropwise condensation of water; however, the applications of these micro- or nanoscale structured surface designs have been restricted by the high manufacturing expenses and short range of subcooling limit. Recent studies have shown that the combination of millimeter sized geometric features and plain hydrophobic coatings can effectively manipulate droplet distribution of water condensate, which provides opportunities to locally facilitate dropwise condensation at relatively low manufacturing expenses as compared to those delicate micro- and nano-structured hydrophobic surfaces. Low surface tension fluids such as hydrocarbons pose a unique challenge to achieving dropwise condensation, because common hydrophobic coatings are not capable of repelling low surface tension fluids. Recent development in lubricant infused surfaces (LIS) offers promising solutions to achieving dropwise condensation of low surface tension fluids by replacing the solid-condensate interface in conventional hydrophobic coatings with a smooth lubricant-condensate interface. However, only a few experimental studies have applied LIS to promoting dropwise condensation of low surface tension fluids (y as low as 15 mN/m). In this work, we investigated dropwise condensation of both water (y ~ 72 mN/m) and a low surface tension fluid, namely butane (y - 13 mN/m) on structured surfaces. For water condensation, we studied the effects of millimeter sized geometric structures on dropwise condensation heat transfer under two different environments: pure vapor and an air-vapor mixture. Our experimental results show that, although convex structures enable faster droplet growth in an air-vapor mixture, the same structures impose the opposite effect during pure vapor condensation, hindering droplet growth. We developed a numerical model for each case to predict the heat flux distribution along the structured surface, and the model shows good agreement with experimental results. This work demonstrates that the effects of geometric features on dropwise condensation are not invariable but rather dependent on the scenario of resistances to heat and mass transfer in the system. For butane condensation, based on a design guideline we recently developed for lubricant infused surfaces, we successfully designed an energy-favorable combination of lubricant and structured solid substrate, which was further demonstrated to promote dropwise condensation of butane. The fundamental understanding of dropwise condensation of water and low surface tension fluids on structured surfaces developed in this study provides useful guidelines for condensation applications including power generation, desalination, dew harvesting, and thermal management.

Liquid-Vapor Phase-Change Phenomena

Author : Van P. Carey
Publisher : CRC Press
ISBN 13 : 1498716679
Total Pages : 592 pages
Book Rating : 4.4/5 (987 download)

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Book Synopsis Liquid-Vapor Phase-Change Phenomena by : Van P. Carey

Download or read book Liquid-Vapor Phase-Change Phenomena written by Van P. Carey and published by CRC Press. This book was released on 2018-08-15 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the second edition of Liquid Vapor Phase Change Phenomena was written, research has substantially enhanced the understanding of the effects of nanostructured surfaces, effects of microchannel and nanonchannel geometries and the effects of extreme wetting on liquid-vapor phase change processes. This edition includes significant new coverage of microchannels and nanostructures along with many other updates. More worked examples and numerous new problems have been added along with a complete solutions manual and electronic figures for classroom projection.

Handbook of Phase Change

Author : S.G. Kandlikar
Publisher : Routledge
ISBN 13 : 1351442198
Total Pages : 786 pages
Book Rating : 4.3/5 (514 download)

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Book Synopsis Handbook of Phase Change by : S.G. Kandlikar

Download or read book Handbook of Phase Change written by S.G. Kandlikar and published by Routledge. This book was released on 2019-01-22 with total page 786 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides a comprehensive coverage of the basic phenomena. It contains twenty-five chapters which cover different aspects of boiling and condensation. First the specific topic or phenomenon is described, followed by a brief survey of previous work, a phenomenological model based on current understanding, and finally a set of recommended design equa

Understanding and Controlling Condensation and Frosting Phenomena on Engineered Surfaces

Author : Mohammad Rejaul Haque
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (111 download)

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Book Synopsis Understanding and Controlling Condensation and Frosting Phenomena on Engineered Surfaces by : Mohammad Rejaul Haque

Download or read book Understanding and Controlling Condensation and Frosting Phenomena on Engineered Surfaces written by Mohammad Rejaul Haque and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The significant advancement of micro/nano-structured surface engineering, demands the integration of material science with the heat transfer applications such as condensate harvesting, passive freezing, and frost formation etc. The energy and texture of the solid surface have significant effects on phase change phenomena. This phenomenon is also significantly influenced by environmental factors (temperature and humidity). At atmospheric pressure, a surface below the freezing point temperature for a given relative humidity nucleates water droplets heterogeneously on the surface, and subsequent freezing occurs resulting in frost formation which is a complex and fascinating phenomenon. Frequent defrosting is required to remove the ice that causes substantial economic losses. This work examines the combined effect of surface properties and environmental factors into the fundamental understanding of coalescence and pinning behavior in droplet growth mechanism, and freezing front propagation. Various nano-structured surfaces and engineered surfaces were fabricated to get the different surface energies and texture effects on droplet dynamics. After testing the wetting properties of every individual samples, condensation/freezing tests were conducted on the samples in humidity and temperature controlled chamber. The nanopillar surfaces had a significant effect on droplet dynamics via the pinning mechanism, and reduced the occurrences of coalescence events. Nanopillared surface accelerated freezing by order of magnitude compared to a plain hydrophilic surface at 60% RH. A mathematical model was developed for the pinning mechanism as a function of design parameters (pillar height, spacing, and radius) of the fabricated nanopillar surface. For the condensation test on graphene oxide (GO) coated copper surface, the pinning of droplets into the micro/nanostructures of the surfaces leads to the enhancement of condensate harvesting. The hydrophobic aluminum (Al-H), and hydrophobic graphene coated surface delays the freezing. The change in freezing kinetics, freezing time, the size of droplets at freezing, and the surface area covered at freezing, are all related to the rate of coalescence of droplets on the surface. Approximate ~6.78×, ~13.12× and ~17.32× freezing delay was observed at 269 K, 270 K, and 271 K surface temperatures respectively for the hydrophobic graphene surface compared to the plain silicon surface under same operating condition. The result promises the applicability of different engineered surfaces for significant energy savings in frost delaying, thermal management, and condensate harvesting applications.