Download or read book Additive Manufactured Microstructures and Designs for High Heat Flux Dissipation During Pool Boiling written by Austin Hayes and published by . This book was released on 2018 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Heat dissipation is vital in industries requiring predictable operating temperatures while also producing large heat fluxes. These industries include electronics and power generation. For electronics, as more devices fit on a smaller area, the heat flux increases dramatically. Pool boiling offers a solution to electronic cooling due to extremely high heat transfer with a low temperature change. Previous research has focused on coatings and precision manufacturing to create microchannels and features for boiling augmentation. However, this is limited to designs for subtractive processes. The use of additive manufacturing (AM) offers a novel way of thinking of design for boiling enhancement. 3-D boiling structures are fabricated out of aluminum using the Vader System's magnetojet printer. Three generations of geometric structures are created: a volcano-with-holes, a miniaturized volcano-with-holes, and a modular volcano-with-holes. These designs are not easily manufactured using standard techniques. As such, three-dimensional bubble dynamics are currently being explored using high speed imaging and particle image velocimetry. By printing a volcano shape with base holes, the liquid and vapor phases are physically separated in a process termed macroscale liquid-vapor pathways. The singular volcano-with-holes chips achieved a maximum heat flux of 217.3 W/cm2 with a maximum heat transfer coefficient (HTC) of 97.2 kW/m2K (81% improvement over plain). By producing four volcanoes on a single chip, the liquid flow length inside the volcano, which acts as the entrance length, is reduced by 50% and the HTC greatly increased. The highest performing miniaturized volcano-with-holes chip reached a maximum heat flux of 223.1W/cm2 with a maximum HTC of 139.1 kW/m2K (150% improvement over plain). Additionally, the highest performing miniaturized chip was printed on top of a microchannel array. This resulted in combined enhancement from both microchannel and bubble dynamics resulting in a maximum heat flux of 228.4 W/cm2 with a HTC of 339.6 kW/m2K (533% improvement over plain). Finally, a modular structure was created to determine the individual influence of conduction and bubble dynamic augmentation on boiling enhancement. The modular designs show an 83% improvement in CHF (202.4 W/cm2) over plain copper chips and a 83% improvement in HTC(139.0 kW/m2K). This indicates boiling enhancement arises from three-dimensional control over bubble dynamics, resulting in macroscale separate liquid-vapor pathways."--Abstract.

Download or read book Directional Notches as Microstructures to Promote Nucleation and Heat Transfer in Pool Boiling written by Callum McLaughlin and published by . This book was released on 2019 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Heat generation in electronic hardware has become a major limiting factor in achieving maximum efficiency in modern computer parts. Classically forced flow convection systems are used to remove this heat at high rates but can be costly to implement and can take up space that may be needed for other critical components. In response to this, systems that use fewer parts scale in compact spaces are needed. In these situations, pool boiling as a heat transfer mechanism can excel. Pool boiling removes heat through the evaporation of fluid. On a flat surface pool boiling is chaotic and this random nature may hinder its ability to remove heat as effectively. The surface geometry of a pool boiling system can be altered to direct the flow of generated vapor bubbles to allow for increased heat flow and higher heat transfer performance. By creating paths for the vapor to follow we can induce currents in the flow of cool fluid to the heater surface, creating a faster cycle of vapor production therefore cooling the heated surface at a faster rate. The purpose of this study is to investigate angled chip notches as an alternative to already existing high heat transfer surfaces in pool boiling. These alternative chips may prove cheaper or easier to produce the alternative which may incorporate fine, hard to produce features or post process coatings like sintering and the addition of hydrophobic materials. This study will examine the effect these specifically designed notches have on the interaction between the directed vapor and the liquid pathways they create. By creating notches in the surface of the chip, vapor bubble is given sites to nucleate and form vapor pathways. The angle walls on the one side of the notch will act as a wedge when water being driven toward the notch pushes the nucleating bubble up and out of the notch. Combined with pairing nucleating notches up with another oppositely facing one the vapor bubble is departing earlier then it would have had it not been assisted by these surface elements. With just these paired notches placed in row, an HTC improvement of 158% was recorded, compared to a plain copper surface. With the inclusion of microchannels this improvement was brought up to 161%"--Abstract.

Download or read book Multiscale Mechanistic Approach to Enhance Pool Boiling Performance for High Heat Flux Applications written by Arvind Jaikumar and published by . This book was released on 2017 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The advent of cloud computing and the complex packaging architecture of next generation electronic devices drives methods for advanced thermal management solutions. Convection based single-phase cooling systems are inefficient due to their large pressure drops, fluid temperature differences and costs, and are incapable of meeting the cooling requirements in the high power density components and systems. Alternatively, phase-change cooling techniques are attractive due to their ability to remove large amounts of heat while maintaining uniform fluid temperatures. Pool boiling heat transfer mechanism centers on the nucleation, growth and departure of a bubble from the heat transfer surface in a stagnant pool of liquid. The pool boiling performance is quantified by the Critical Heat Flux (CHF) and Heat Transfer Coefficients (HTC) which dictate the operating ranges and efficiency of the heat transfer process. In this work, three novel geometries are introduced to modify the nucleation characteristics, liquid pathways and contact line motion on the prime heater surface for a simultaneous increase in CHF and HTC. First, sintered microchannels and nucleating region with feeder channels (NRFC) were developed through the mechanistic concept of separate liquid-vapor pathways and enhanced macroconvection heat transfer. A maximum CHF of 420 W/cm2 at a wall superheat of 1.7 °C with a HTC of 2900 MW/m2°C was achieved with the sintered-channels configuration, while the NRFC reached a CHF of 394 W/cm2 with a HTC of 713 kW/m2°C. Second, the scale effect of liquid wettability, roughness and microlayer evaporation was exploited to facilitate capillary wicking in graphene through interlaced porous copper particles. A CHF of 220 W/cm2 with a HTC of 155 kW/m2°C was achieved using an electrodeposition coating technique. Third, the chemical heterogeneity on nanoscale coatings was shown to increase the contribution from transient conduction mechanisms. A maximum CHF of 226 W/cm2 with a HTC of 107 kW/m2°C was achieved. The enhancement techniques developed here provide a mechanistic tool at the microscale and nanoscale to increase the boiling CHF and HTC."--Abstract.

Download or read book Al Si Alloys written by Francisco C. Robles Hernandez and published by Springer. This book was released on 2017-07-02 with total page 253 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book details aluminum alloys with special focus on the aluminum silicon (Al‐Si) systems – that are the most abundant alloys second only to steel. The authors include a description of the manufacturing principles, thermodynamics, and other main characteristics of Al‐Si alloys. Principles of processing, testing, and in particular applications in the Automotive, Aeronautical and Aerospace fields are addressed.

Download or read book Transport Phenomena in Multiphase Systems written by Amir Faghri and published by Academic Press. This book was released on 2006 with total page 1072 pages. Available in PDF, EPUB and Kindle. Book excerpt: Engineering students in a wide variety of engineering disciplines from mechanical and chemical to biomedical and materials engineering must master the principles of transport phenomena as an essential tool in analyzing and designing any system or systems wherein momentum, heat and mass are transferred. This textbook was developed to address that need, with a clear presentation of the fundamentals, ample problem sets to reinforce that knowledge, and tangible examples of how this knowledge is put to use in engineering design. Professional engineers, too, will find this book invaluable as reference for everything from heat exchanger design to chemical processing system design and more. * Develops an understanding of the thermal and physical behavior of multiphase systems with phase change, including microscale and porosity, for practical applications in heat transfer, bioengineering, materials science, nuclear engineering, environmental engineering, process engineering, biotechnology and nanotechnology * Brings all three forms of phase change, i.e., liquid vapor, solid liquid and solid vapor, into one volume and describes them from one perspective in the context of fundamental treatment * Presents the generalized integral and differential transport phenomena equations for multi-component multiphase systems in local instance as well as averaging formulations. The molecular approach is also discussed with the connection between microscopic and molecular approaches * Presents basic principles of analyzing transport phenomena in multiphase systems with emphasis on melting, solidification, sublimation, vapor deposition, condensation, evaporation, boiling and two-phase flow heat transfer at the micro and macro levels * Solid/liquid/vapor interfacial phenomena, including the concepts of surface tension, wetting phenomena, disjoining pressure, contact angle, thin films and capillary phenomena, including interfacial balances for mass, species, momentum, and energy for multi-component and multiphase interfaces are discussed * Ample examples and end-of-chapter problems, with Solutions Manual and PowerPoint presentation available to the instructors

Download or read book Manufacturing and Application of Stainless Steels written by Andrea Di Schino and published by MDPI. This book was released on 2020-04-15 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stainless steels represent a quite interesting material family, both from a scientific and commercial point of view, following to their excellent combination in terms of strength and ductility together with corrosion resistance. Thanks to such properties, stainless steels have been indispensable for the technological progress during the last century and their annual consumption increased faster than other materials. They find application in all these fields requiring good corrosion resistance together with ability to be worked into complex geometries. Despite to their diffusion as a consolidated materials, many research fields are active regarding the possibility to increase stainless steels mechanical properties and corrosion resistance by grain refinement or by alloying by interstitial elements. At the same time innovations are coming from the manufacturing process of such a family of materials, also including the possibility to manufacture them starting from metals powder for 3D printing. The Special Issue scope embraces interdisciplinary work covering physical metallurgy and processes, reporting about experimental and theoretical progress concerning microstructural evolution during processing, microstructure-properties relations, applications including automotive, energy and structural.

Download or read book Advanced Materials for Thermal Management of Electronic Packaging written by Xingcun Colin Tong and published by Springer Science & Business Media. This book was released on 2011-01-05 with total page 633 pages. Available in PDF, EPUB and Kindle. Book excerpt: The need for advanced thermal management materials in electronic packaging has been widely recognized as thermal challenges become barriers to the electronic industry’s ability to provide continued improvements in device and system performance. With increased performance requirements for smaller, more capable, and more efficient electronic power devices, systems ranging from active electronically scanned radar arrays to web servers all require components that can dissipate heat efficiently. This requires that the materials have high capability of dissipating heat and maintaining compatibility with the die and electronic packaging. In response to critical needs, there have been revolutionary advances in thermal management materials and technologies for active and passive cooling that promise integrable and cost-effective thermal management solutions. This book meets the need for a comprehensive approach to advanced thermal management in electronic packaging, with coverage of the fundamentals of heat transfer, component design guidelines, materials selection and assessment, air, liquid, and thermoelectric cooling, characterization techniques and methodology, processing and manufacturing technology, balance between cost and performance, and application niches. The final chapter presents a roadmap and future perspective on developments in advanced thermal management materials for electronic packaging.

Download or read book Hydrodynamic Aspects of Boiling Heat Transfer written by N. Zuber and published by . This book was released on 1959 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design of Shape Memory Alloy SMA Actuators written by Ashwin Rao and published by Springer. This book was released on 2015-05-08 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: This short monograph presents an analysis and design methodology for shape memory alloy (SMA) components such as wires, beams, and springs for different applications. The solid-solid, diffusionless phase transformations in thermally responsive SMA allows them to demonstrate unique characteristics like superelasticity and shape memory effects. The combined sensing and actuating capabilities of such materials allows them to provide a system level response by combining multiple functions in a single material system. In SMA, the combined mechanical and thermal loading effects influence the functionality of such materials. The aim of this book is to make the analysis of these materials accessible to designers by developing a "strength of materials" approach to the analysis and design of such SMA components inspired from their various applications with a review of various factors influencing the design process for such materials.

Download or read book Fundamentals of Multiphase Flow written by Christopher E. Brennen and published by Cambridge University Press. This book was released on 2005-04-18 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: Publisher Description

Download or read book An Introduction to Transport Phenomena In Materials Engineering 2nd edition written by David Gaskell and published by Momentum Press. This book was released on 2012-08-24 with total page 686 pages. Available in PDF, EPUB and Kindle. Book excerpt: This classic text on fluid flow, heat transfer, and mass transport has been brought up to date in this second edition. The author has added a chapter on “Boiling and Condensation” that expands and rounds out the book’s comprehensive coverage on transport phenomena. These new topics are particularly important to current research in renewable energy resources involving technologies such as windmills and solar panels. The book provides you and other materials science and engineering students and professionals with a clear yet thorough introduction to these important concepts. It balances the explanation of the fundamentals governing fluid flow and the transport of heat and mass with common applications of these fundamentals to specific systems existing in materials engineering. You will benefit from: • The use of familiar examples such as air and water to introduce the influences of properties and geometry on fluid flow. • An organization with sections dealing separately with fluid flow, heat transfer, and mass transport. This sequential structure allows the development of heat transport concepts to employ analogies of heat flow with fluid flow and the development of mass transport concepts to employ analogies with heat transport. • Ample high-quality graphs and figures throughout. • Key points presented in chapter summaries. • End of chapter exercises and solutions to selected problems. • An all new and improved comprehensive index.

Download or read book The Solid Liquid Interface written by D. P. Woodruff and published by CUP Archive. This book was released on 1973-11-15 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: This 1973 book aims to describe the basic physical changes of the solid-liquid interface.

Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1994 with total page 1036 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advances in Computational Methods in Manufacturing written by R. Ganesh Narayanan and published by Springer Nature. This book was released on 2019-10-17 with total page 1092 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents a selection of papers from the 2nd International Conference on Computational Methods in Manufacturing (ICCMM 2019). The papers cover the recent advances in computational methods for simulating various manufacturing processes like machining, laser welding, laser bending, strip rolling, surface characterization and measurement. Articles in this volume discuss both the development of new methods and the application and efficacy of existing computational methods in manufacturing sector. This volume will be of interest to researchers in both industry and academia working on computational methods in manufacturing.

Download or read book Materials and Processes written by Barrie D. Dunn and published by Springer. This book was released on 2015-12-29 with total page 677 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this book is to assist scientists and engineers select the ideal material or manufacturing process for particular applications; these could cover a wide range of fields, from light-weight structures to electronic hardware. The book will help in problem solving as it also presents more than 100 case studies and failure investigations from the space sector that can, by analogy, be applied to other industries. Difficult-to-find material data is included for reference. The sciences of metallic (primarily) and organic materials presented throughout the book demonstrate how they can be applied as an integral part of spacecraft product assurance schemes, which involve quality, material and processes evaluations, and the selection of mechanical and component parts. In this successor edition, which has been revised and updated, engineering problems associated with critical spacecraft hardware and the space environment are highlighted by over 500 illustrations including micrographs and fractographs. Space hardware captured by astronauts and returned to Earth from long durations in space are examined. Information detailed in the Handbook is applicable to general terrestrial applications including consumer electronics as well as high reliability systems associated with aeronautics, medical equipment and ground transportation. This Handbook is also directed to those involved in maximizing the relia bility of new materials and processes for space technology and space engineering. It will be invaluable to engineers concerned with the construction of advanced structures or mechanical and electronic sub-systems.

Download or read book Functionally Graded Materials FGMs written by Pulak M. Pandey and published by CRC Press. This book was released on 2021-09-14 with total page 255 pages. Available in PDF, EPUB and Kindle. Book excerpt: The science and study of functionally graded materials (FGMs) have intrigued researchers over the last few decades. Their application has the capability to produce parts with unmatched properties which are virtually impossible to obtain via conventional material routes. This book addresses various FGM aspects and provides a relevant, high-quality, and comprehensive data source. The book covers trends, process classification on various bases, physical processes involved, structure, properties, applications, advantages, and limitations. Emerging trends in the field are discussed in detail and advancements are thoroughly reviewed and presented to broaden the spectrum of FGM applications. This reference book will be of interest to scholars, researchers, academicians, industry practitioners, government labs, libraries, and anyone interested in the area of materials engineering.

Download or read book Plastics Materials and Processes written by Charles A. Harper and published by John Wiley & Sons. This book was released on 2003-10-10 with total page 1008 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plastics Materials and Processes: A Concise Encyclopedia is a resource for anyone with an interest in plastic materials and processes, from seasoned professionals to laypeople. Arranged in alphabetical order, it clearly explains all of the materials and processes as well as their major application areas and usages. Plastics Materials and Processes: A Concise Encyclopedia: Discusses and describes applications and practical uses of the materials and processes. Clear definitions and sufficient depth to satisfy the information seekers needs