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Flow Boiling Heat Transfer In Narrow Vertical Channels

Flow Boiling Heat Transfer in Narrow Vertical Channels PDF

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Author:
Publisher: Cuvillier Verlag
ISBN: 3736912404
Size: 39.65 MB
Format: PDF, Mobi
Category : Technology & Engineering
Languages : de
Pages : 136
View: 3658


Saturated flow boiling heat transfer and flow visualization experiments were carried out in three vertical rectangular channels with dimensions (width×height) 2.0×4.0, 0.86×2.0 and 0.54×1.60 mm² (corresponding to hydraulic diameters 2.67, 1.20 and 0.81 mm, respectively). The channels were heated from three sides. Deionized water was used as the working fluid. The channel exit was at atmospheric pressure. Benchmark experiments of single-phase flow were also conducted for pressure drop and heat transfer. Experimental results show that for the 0.54×1.60 mm² channel, the singlephase friction factor is higher than predicted by well-accepted correlations, while for the other two channels it can be well correlated. The heat transfer performance for both laminar and turbulent regimes under asymmetric heating conditions is different from that under uniform heating conditions on which the existing correlations are based. Therefore single-phase heat transfer correlations were modified so that they could be incorporated into the two-phase heat transfer correlations employed for asymmetric heating conditions. For flow boiling, three basic flow patterns are observed for all the channels, viz., bubbly, slug and annular flow. However, based on the developed flow pattern maps, the transition from slug to annular flow for the 2.0×4.0 mm² channel occurs at a lower superficial vapor velocity than for the two small channels. This suggests that the nucleate boiling mechanism, which generally corresponds to slug flow, is more important for the two small channels. Saturated flow boiling heat transfer characteristics were investigated under different heat flux, mass flux and vapor quality. The experimental local heat transfer coefficient for the 2.0×4.0 mm² channel is in good agreement with the modified Kandlikar correlation and the Shah correlation. For the smaller channels (0.86×2.0 mm² and 0.54×1.60 mm²), the heat transfer characteristics are not dominated by the convective boiling mechanism. On the contrary, the nucleate boiling term of the Kandlikar correlation predicts the experimental heat transfer coefficient relatively well. Two new correlations have been developed in which the local two-phase heat transfer coefficient is related to the single-phase heat transfer coefficient by a twophase multiplier, which is a function of the Boiling number and thermodynamic vapor quality. The developed correlations show rather good agreement with experimental results.

Buoyancy Driven Two Phase Flow And Boiling Heat Transfer In Narrow Vertical Channels

Buoyancy driven Two Phase Flow and Boiling Heat Transfer in Narrow Vertical Channels PDF

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Author: Karl John Larson Geisler
Publisher:
ISBN:
Size: 75.86 MB
Format: PDF, ePub, Mobi
Category :
Languages : en
Pages : 738
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Heat Transfer And Fluid Flow In Minichannels And Microchannels

Heat Transfer and Fluid Flow in Minichannels and Microchannels PDF

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Author: Satish Kandlikar
Publisher: Butterworth-Heinemann
ISBN: 0080983510
Size: 72.11 MB
Format: PDF, Mobi
Category : Science
Languages : en
Pages : 592
View: 7744


Heat exchangers with minichannel and microchannel flow passages are becoming increasingly popular due to their ability to remove large heat fluxes under single-phase and two-phase applications. Heat Transfer and Fluid Flow in Minichannels and Microchannels methodically covers gas, liquid, and electrokinetic flows, as well as flow boiling and condensation, in minichannel and microchannel applications. Examining biomedical applications as well, the book is an ideal reference for anyone involved in the design processes of microchannel flow passages in a heat exchanger. Each chapter is accompanied by a real-life case study New edition of the first book that solely deals with heat and fluid flow in minichannels and microchannels Presents findings that are directly useful to designers; researchers can use the information in developing new models or identifying research needs

Vdi W Rmeatlas

VDI W  rmeatlas PDF

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Author: VDI-Gesellschaft Verfahrenstechnik und Chemieingenieurwesen(GVC)
Publisher: Springer-Verlag
ISBN: 3662107457
Size: 62.90 MB
Format: PDF, Docs
Category : Science
Languages : de
Pages : 1414
View: 2356


Der VDI-Wärmeatlas enthält alle wichtigen Berechnungsmethoden für die thermische Auslegung von Apparaten und Anlagen. Es werden jeweils nur die von Experten geprüften und als derzeit besten empfohlenen Gleichungen zur Berechnung ausgegeben. Beispiele erleichtern dem Nutzer die Anwendung. Nur wer die aktuelle Ausgabe des VDI-Wärmeatlas besitzt, kann wirklich konkurrenzfähig anbieten!

Vdi W Rmeatlas

VDI W  rmeatlas PDF

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Author: Verein Deutscher Ingenieure, VDI-Gesellschaft Verf
Publisher: Springer-Verlag
ISBN: 3662107430
Size: 25.37 MB
Format: PDF, Mobi
Category : Science
Languages : de
Pages : 1499
View: 5662


Der VDI-Wärmeatlas ist ein unentbehrliches Arbeitsmittel für den Ingenieur, der sich mit Fragen zur Wärme- und Stoffübertragung beschäftigt. Das Werk ermöglicht die technisch wie wirtschaftlich optimale Auslegung verfahrenstechnischer Apparate und Anlagen. Da alle Beiträge einem umfassenden fachlichen Prüfverfahren unterzogen wurden, erhält der Nutzer ein Höchstmaß an Sicherheit, dass die Daten, Berechnungsverfahren und Aussagen dem neuesten Stand des Wissens entsprechen. Auf Grund jüngster Entwicklungen und mit Blick auf erkennbare Trends wurde die 9. Auflage zum Teil neu strukturiert. Sie zeichnet sich gegenüber der Vorauflage dadurch aus, dass sie neben zahlreichen Aktualisierungen und Ergänzungen auch viele völlig neu geschriebene Beiträge enthält (v.a. in Teil L: Druckverlustberechnung). Um wie bisher allen Interessenten gerecht zu werden, gibt es den Wärmeatlas weiterhin in Buchform, als Ringbuch und CD-ROM.

Fluid Flow Heat Transfer And Boiling In Micro Channels

Fluid Flow  Heat Transfer and Boiling in Micro Channels PDF

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Author: L. P. Yarin
Publisher: Springer Science & Business Media
ISBN: 3540787550
Size: 80.27 MB
Format: PDF, ePub, Mobi
Category : Science
Languages : en
Pages : 481
View: 4497


The subject of the book is uid dynamics and heat transfer in micro-channels. This problem is important for understanding the complex phenomena associated with single- and two-phase ows in heated micro-channels. The challenge posed by high heat uxes in electronic chips makes thermal management a key factor in the development of these systems. Cooling of mic- electronic components by new cooling technologies, as well as improvement of the existing ones, is becoming a necessity as the power dissipation levels of integrated circuits increases and their sizes decrease. Miniature heat sinks with liquid ows in silicon wafers could signi cantly improve the performance and reliability of se- conductor devices. The improvements are made by increasing the effective thermal conductivity, by reducing the temperature gradient across the wafer, by reducing the maximum wafer temperature, and also by reducing the number and intensity of localized hot spots. A possible way to enhance heat transfer in systems with high power density is to change the phase in the micro-channels embedded in the device. This has motivated a number of theoretical and experimental investigations covering various aspects of heat transfer in micro-channel heat sinks with phase change. The ow and heat transfer in heated micro-channels are accompanied by a n- ber of thermohydrodynamic processes, such as liquid heating and vaporization, bo- ing, formation of two-phase mixtures with a very complicated inner structure, etc., which affect signi cantly the hydrodynamic and thermal characteristics of the co- ing systems.

Encyclopedia Of Thermal Packaging Set 1 Thermal Packaging Techniques A 6 Volume Set

Encyclopedia Of Thermal Packaging   Set 1  Thermal Packaging Techniques  A 6 volume Set  PDF

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Author:
Publisher: World Scientific
ISBN: 9814452599
Size: 46.33 MB
Format: PDF, Docs
Category : Technology & Engineering
Languages : en
Pages : 1580
View: 2562


remove This Encyclopedia comes in 3 sets. To check out Set 2 and Set 3, please visit Set 2: Thermal Packaging Tools and Set 3: Thermal Packaging Applications /remove Thermal and mechanical packaging — the enabling technologies for the physical implementation of electronic systems - are responsible for much of the progress in miniaturization, reliability, and functional density achieved by electronic, microelectronic, and nanoelectronic products during the past 50 years. The inherent inefficiency of electronic devices and their sensitivity to heat have placed thermal packaging on the critical path of nearly every product development effort in traditional, as well as emerging, electronic product categories.Successful thermal packaging is the key differentiator in electronic products, as diverse as supercomputers and cell phones, and continues to be of pivotal importance in the refinement of traditional products and in the development of products for new applications. The Encyclopedia of Thermal Packaging, compiled in multi-volume sets (Set 1: Thermal Packaging Techniques, Set 2: Thermal Packaging Tools, Set 3: Thermal Packaging Applications, and Set 4: Thermal Packaging Configurations) will provide a comprehensive, one-stop treatment of the techniques, tools, applications, and configurations of electronic thermal packaging. Each of the author-written sets presents the accumulated wisdom and shared perspectives of a few luminaries in the thermal management of electronics.Set 1: Thermal Packaging TechniquesThe first set of the Encyclopedia, Thermal Packaging Techniques, focuses on the technology “building blocks” used to assemble a complete thermal management system and provide detailed descriptions of the underlying phenomena, modeling equations, and correlations, as well as guidance for achieving the optimal designs of individual “building blocks” and their insertion in the overall thermal solution. Specific volumes deal with microchannel coolers, cold plates, immersion cooling modules, thermoelectric microcoolers, and cooling devices for solid state lighting systems, as well as techniques and procedures for the experimental characterization of thermal management components. These “building blocks” are the essential elements in the creation of a complete, cost-effective thermal management system.The four sets in the Encyclopedia of Thermal Packaging will provide the novice and student with a complete reference for a quick ascent on the thermal packaging ';learning curve,'; the practitioner with a validated set of techniques and tools to face every challenge, and researchers with a clear definition of the state-of-the-art and emerging needs to guide their future efforts. This encyclopedia will, thus, be of great interest to packaging engineers, electronic product development engineers, and product managers, as well as to researchers in thermal management of electronic and photonic components and systems, and most beneficial to undergraduate and graduate students studying mechanical, electrical, and electronic engineering.

Convective Flow Boiling

Convective Flow Boiling PDF

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Author: John C. Chen
Publisher: CRC Press
ISBN: 1000716031
Size: 46.14 MB
Format: PDF, ePub, Docs
Category : Science
Languages : en
Pages : 304
View: 1839


This book comprises selected papers from the First International Conference on Convective Flow Boiling. The purpose of the conference is to examine state-of-science and recent developments in technology of flow boiling, i.e., boiling systems which are affected by convective flows.

Advances In Heat Transfer

Advances in Heat Transfer PDF

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Author:
Publisher: Academic Press
ISBN: 9780080575711
Size: 18.12 MB
Format: PDF
Category : Science
Languages : en
Pages : 354
View: 7737


Advances in Heat Transfer

Microscale Heat Transfer Fundamentals And Applications

Microscale Heat Transfer   Fundamentals and Applications PDF

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Author: S. Kakaç
Publisher: Springer Science & Business Media
ISBN: 1402033613
Size: 34.49 MB
Format: PDF, Docs
Category : Technology & Engineering
Languages : en
Pages : 509
View: 7505


This volume contains an archival record of the NATO Advanced Institute on Microscale Heat Transfer – Fundamental and Applications in Biological and Microelectromechanical Systems held in Çesme – Izmir, Turkey, July 18–30, 2004. The ASIs are intended to be high-level teaching activity in scientific and technical areas of current concern. In this volume, the reader may find interesting chapters and various Microscale Heat Transfer Fundamental and Applications. The growing use of electronics, in both military and civilian applications has led to the widespread recognition for need of thermal packaging and management. The use of higher densities and frequencies in microelectronic circuits for computers are increasing day by day. They require effective cooling due to heat generated that is to be dissipated from a relatively low surface area. Hence, the development of efficient cooling techniques for integrated circuit chips is one of the important contemporary applications of Microscale Heat Transfer which has received much attention for cooling of high power electronics and applications in biomechanical and aerospace industries. Microelectromechanical systems are subject of increasing active research in a widening field of discipline. These topics and others are the main themeof this Institute.

Low Temperature And Cryogenic Refrigeration

Low Temperature and Cryogenic Refrigeration PDF

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Author: Sadik Kakaç
Publisher: Springer Science & Business Media
ISBN: 9401000999
Size: 36.27 MB
Format: PDF, Kindle
Category : Science
Languages : en
Pages : 485
View: 6535


Refrigeration plays a prominent role in our everyday lives, and cryogenics plays a major role in medical science, space technology and the cooling of low-temperature electronics. This volume contains chapters on basic refrigeration systems, non-compression refrigeration and cooling, and topics related to global environmental issues, alternative refrigerants, optimum refrigerant selection, cost-quality optimization of refrigerants, advanced thermodynamics of reverse-cycle machines, applications in medicine, cryogenics, heat pipes, gas-solid absorption refrigeration, multisalt resorption heat pumps, cryocoolers, thermoacoustic refrigeration, cryogenic heat transfer and enhancement and other topics covering theory, design, and applications, such as pulse tube refrigeration, which is the most efficient of all cryocoolers and can be used in space missions.

Emerging Topics In Heat Transfer

Emerging Topics in Heat Transfer PDF

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Author: Qiuwang Wang
Publisher: WIT Press
ISBN: 1845648188
Size: 37.97 MB
Format: PDF, Docs
Category : Science
Languages : en
Pages : 416
View: 6664


Presented in ten edited chapters this book encompasses important emerging topics in heat transfer equipment, particularly heat exchangers. The chapters have all been selected by invitation only. Advances in high temperature equipment and small scale devices continue to be important as the involved heat transfer and related phenomena are often complex in nature and different mechanisms like heat conduction, convection, turbulence, thermal radiation and phase change as well as chemical reactions may occur simultaneously. The book treats various operating problems, like fouling, and highlights applications in heat exchangers and gas turbine cooling. In engineering design and development, reliable and accurate computational methods are required to replace or complement expensive and time consuming experimental trial and error work. Tremendous advancements in knowledge and competence have been achieved during recent years due to improved computational solution methods for non-linear partial differential equations, turbulence modelling advancement and developments of computers and computing algorithms to achieve efficient and rapid simulations. The chapters of the book thoroughly present such advancement in a variety of applications.

Heat Transfer Enhancement Of Heat Exchangers

Heat Transfer Enhancement of Heat Exchangers PDF

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Author: Sadik Kakaç
Publisher: Springer Science & Business Media
ISBN: 9401591598
Size: 22.19 MB
Format: PDF, ePub, Docs
Category : Science
Languages : en
Pages : 676
View: 5260


Heat transfer enhancement in single-phase and two-phase flow heat exchangers in important in such industrial applications as power generating plant, process and chemical industry, heating, ventilation, air conditioning and refrigeration systems, and the cooling of electronic equipment. Energy savings are of primary importance in the design of such systems, leading to more efficient, environmentally friendly devices. This book provides invaluable information for such purposes.

Critical Heat Flux In Flow Boiling In Microchannels

Critical Heat Flux in Flow Boiling in Microchannels PDF

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Author: Sujoy Kumar Saha
Publisher: Springer
ISBN: 3319177354
Size: 40.70 MB
Format: PDF, ePub
Category : Science
Languages : en
Pages : 53
View: 1931


This Brief concerns the important problem of critical heat flux in flow boiling in microchannels. A companion edition in the SpringerBrief Subseries on Thermal Engineering and Applied Science to “Heat Transfer and Pressure Drop in Flow Boiling in Microchannels,” by the same author team, this volume is idea for professionals, researchers, and graduate students concerned with electronic cooling.

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