Download or read book Experimental Investigation of a Micro porous enhanced Surface in Flow Boiling written by Fung Richard Lo and published by . This book was released on 1997 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Flow Boiling of a Dilute Emulsion In Smooth and Rough Microgaps written by Brandon M. Shadakofsky and published by Springer Nature. This book was released on 2023-03-24 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book elucidates heat transfer behavior for boiling of dilute emulsions- mixtures of two immiscible fluids- which has received little attention to date. Of the work completed in this area, the majority has been focused on pool boiling where no mean flow is present, and this book is the first major work to be published regarding flow boiling of emulsions. The book includes a comprehensive review and assessment of research on emulsion-based heat transfer. Recent experiments are reported and analyzed to characterize heat transfer in microgap flow boiling via a systematic investigation into the effects of gap size, mass flux, and volume fraction on the heat transfer coefficient and pressure drop. The emulsion used in all experiments comprises droplets of an immiscible electronics cooling fluid suspended in water. The volume provides a complete baseline for flow boiling of water in the microgaps, enabling a determination of the enhancement of the heat transfer coefficient when the disperse component is present. Moreover, a subset of the data set pertains to flow boiling of dilute emulsions over microporous surfaces. The flow conditions for which the microporous surfaces enhance or degrade heat transfer are presented. Finally, this book provides a discussion of the physical phenomena which affect boiling and a set of nondimensional numbers that can be used for correlation.
Download or read book An Experimental Study of Flow Boiling Heat Transfer Enhancement in Minichannels with Porous Mesh Heating Wall written by Hailei Wang and published by . This book was released on 2006 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Applied mechanics reviews written by and published by . This book was released on 1948 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Investigation of Nucleate Boiling and Thin film Evaporation on Enhanced Silicon Surfaces written by Shailesh Malla and published by . This book was released on 2014 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present work consists of two major studies. The first study investigates the effects of surface energy or wettability on nucleate pool boiling and the second study investigates the thin-film evaporative cooling for near junction thermal management. For the first study, effects of surface energy or wettability on critical heat flux (CHF) and boiling heat transfer (BHT) of smooth heated surfaces was studied in saturated pool boiling of water at 1 atm. For this purpose hydrophilic and hydrophobic surfaces were created on one side of 1cm x 1cm double-side polished silicon substrates. A resistive heating layer was applied on the opposite side of each substrate. The surface energies of the created surfaces were characterized by measuring the static contact angles of water sessile drops. To provide a wide range of surface energies, surfaces were made of Teflon (hydrophobic), bare silicon (hydrophilic) and aluminum oxide (most hydrophilic). The measured contact angles on these surfaces were ~108, ~57 and ~13 degrees respectively. The results of pool boiling tests on these surfaces clearly illustrate the connection between surface energy and CHF. CHF was shown to linearly decrease with contact angle increase, from ~125 W/cm2 on aluminum oxide (most hydrophilic) to nearly one tenth of this value on Teflon (hydrophobic). The most hydrophilic surface also produced increasingly better BHT than plain silicon and Teflon as heat flux increased. However, below ~5 W/cm2 the hydrophobic surface demonstrated better heat transfer due to earlier onset of nucleate boiling, reducing surface superheats by up to ~5 degrees relative to the other two surfaces. Above ~5 W/cm2 the BHT of the hydrophobic surface rapidly deteriorated as superheat increased towards the value at CHF. To further understand the effect of surface energy on pool boiling performance, the growth and departure of bubbles from single nucleating sites on each surface were analyzed from high-speed video recordings. A distinct bubble behavior was observed in the hydrophobic surface where bubble growth and departure period was extremely long compared to plain silicon and aluminum oxide surfaces. This study also investigated the performance of thin-film evaporative cooling for near-junction thermal management. A liquid delivery system capable of delivering water in small volumes ranging 20~75 nl at frequencies of up to 600 Hz was established. On one side of the silicon chip, a resistive heating layer of 2 mm x 2 mm was fabricated to emulate the high heat flux hot-spot, and on the other side a superhydrophilic nanoporous coating (SHNC) was applied over an area of 1 cm x 1 cm. With the aid of the nanoporous coating, delivered droplets spread into thin films of thicknesses less than 10[mu]m. With this system, evaporative tests were conducted in ambient in an effort to maximize dryout heat flux and evaporative heat transfer coefficient. During the tests, heat flux at the hot spot was varied to values above 1000 W/cm2. Water was delivered at either given constant frequency (constant mass flow rate) or at programmed variations of frequency (variable mass flow rate), for a given nanoliter dose volume. Heat flux and hot spot surface temperatures were recorded upon reaching steady state at each applied heat flux increment. Relative to bare silicon surface, dryout heat flux of the SHNC surface was found to increase by ~5 times at 500~600 Hz. Tests were also conducted at various system pressures and temperatures in a micro-gap to emulate the actual embedded thermal management system. The micro-gap was made by positioning a top cover plate 500 [mu]m above the test surface. System temperature did not influence the hotspot temperature. This was due to the formation of near saturation temperature inside the micro-gap for all cases as a result of vapor accumulation. Increase in system pressure increased the hotspot temperature. At 1500 W/cm2, hotspot temperature increased by 6 C and 24 C by increasing the system pressure by 7.32 and 14.7 psi respectively. This was due to increase in saturation point as a result of increase in pressure. On the SHNC surface a mixed mode of heat transfer comprising of thin-film boiling and thin-film evaporation was observed particularly at moderate heat flux (~700 W/cm2). To further enhance the heat transfer coefficient, aluminum microporous coating was developed that increased the number of nucleation sites for thin-film boiling and also maintained the wettability for thin-film evaporation at higher heat fluxes. Test results showed a marginal improvement in dry-out heat flux compared to SHNC, however, significant reduction was achieved in hot-spot temperature at all heat flux levels. A net reduction of ~ 58oC was obtained at ~1600 W/cm2 by using aluminum based microporous coating.
Download or read book Recent Advances in Mechanical Engineering written by K.M. Pandey and published by Springer Nature. This book was released on 2021-01-10 with total page 949 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the select proceedings of the International Conference on Recent Advancements in Mechanical Engineering (ICRAME 2020). It provides a comprehensive overview of the various technical challenges faced, their systematic investigation, contemporary developments, and future perspectives in the domain of mechanical engineering. The book covers a wide array of topics including fluid flow techniques, compressible flows, waste management and waste disposal, bio-fuels, renewable energy, cryogenic applications, computing in applied mechanics, product design, dynamics and control of structures, fracture and failure mechanics, solid mechanics, finite element analysis, tribology, nano-mechanics and MEMS, robotics, supply chain management and logistics, intelligent manufacturing system, rapid prototyping and reverse engineering, quality control and reliability, conventional and non-conventional machining, and ergonomics. This book can be useful for students and researchers interested in mechanical engineering and its allied fields.
Download or read book Investigation of Separate Effects of Surface Condition on Subcooled Flow Boiling Heat Transfer written by Jee Hyun Seong and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The experimental results showed that groove pattern, average roughness, and wettability do not affect subcooled flow boiling. Instead, they suggest that the process is determined by the location, size, and shape of cavities, and that micro-scale surface modifications (e.g., porous cracks) or nano-scale structures play a crucial role in the formation of active nucleation cavities and modify the bubble dynamics. A key takeaway from this study is that, to elucidate how surface modifications affect boiling heat transfer, one should carefully examine how the surface morphology changes at both the micro- and nano-scale and how the surface preparation process affect the formation of cavities.
Download or read book Advances in Heat Transfer Enhancement written by Sujoy Kumar Saha and published by Springer. This book was released on 2016-04-23 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Brief addresses the phenomena of heat transfer enhancement. A companion edition in the SpringerBrief Subseries on Thermal Engineering and Applied Science to three other monographs including “Critical Heat Flux in Flow Boiling in Microchannels,” this volume is idea for professionals, researchers, and graduate students concerned with electronic cooling.
Download or read book Heat Transfer and Fluid Flow in Minichannels and Microchannels written by Satish Kandlikar and published by Elsevier. This book was released on 2006 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt: &Quot;This book explores flow through passages with hydraulic diameters from about 1 [mu]m to 3 mm, covering the range of minichannels and microchannels. Design equations along with solved examples and practice problems are also included to serve the needs of practicing engineers and students in a graduate course."--BOOK JACKET.
Download or read book Handbook of Porous Media written by Kambiz Vafai and published by CRC Press. This book was released on 2000-07-12 with total page 936 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Presents the most important and up-to-date research related to heat transfer in porous media, focusing on practical applications of the latest studies to engineering products and procedures. Includes theoretical models of fluid flow, capillary effects, application of fractal and percolation characterizing porous materials, multiphase flow and heat transfer, turbulent flow and heat transfer, improved measurement and flow visualization techniques, and enhanced design correlations."
Download or read book Advances in Heat Transfer written by Ephraim M. Sparrow and published by Academic Press. This book was released on 2021-12-01 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Heat Transfer, Volume 53 in this long-running serial, highlights new advances in the field, with this new 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 the Advances in Heat Transfer series
Download or read book Microchannel Phase Change Transport Phenomena written by Sujoy Kumar Saha and published by Butterworth-Heinemann. This book was released on 2015-09-27 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microchannel Heat transfer is the cooling application of high power density microchips in the CPU system, micropower systems and many other large scale thermal systems requiring effective cooling capacity. This book offers the latest research and recommended models on the microsize cooling system which not only significantly reduces the weight load, but also enhances the capability to remove much greater amount of heat than any of large scale cooling systems. A detailed reference in microchannel phase change (boiling and condensation) including recommended models and correlations for various requirements such as pressure loss, and heat transfer coefficient. Researchers, engineers, designers and students will benefit from the collated, state-of-the-art of the research put together in this book and its systematic, addressing all the relevant issues and providing a good reference for solving problems of critical analysis. Up-to-date information will help delineate further research direction in the microchannel heat transfer The latest modeling information and recommendations will help in design method and purpose
Download or read book Terotechnology written by Radek, N. and published by Materials Research Forum LLC. This book was released on 2018-08-25 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: The volume presents advances in materials research and technology in the area of terotechnology, i.e. the technology of installation, maintenance, replacement and removal of plant machinery and equipment, reliability analysis, technical diagnostics, tribology and technical safety. Specific topics include Cavitation Erosion, Simulation of Particle Erosion, Mechanically-assisted Laser Forming, Laser Machining of Tool Steels, Titanium Carbonitride Coatings, Causes of Cracks in Thermit Welds, Diamond-Like Coatings on Titanium, Reinforcement of Concrete, Fatigue Strength of Construction Elements, Modeling of Mining Support Structures, Surface Treatments of Sintered Stainless Steel, Thermal Welding, Joints of Nickel-Based Superalloys, Robotic Laser Cleaning of Materials, Tribological Properties of Laser-processed ESD Coatings, Laser-modified WC-Cu Electro-Spark Coatings, anti-Graffiti Coating Systems.
Download or read book Encyclopedia Of Two phase Heat Transfer And Flow Iii Macro And Micro Flow Boiling And Numerical Modeling Fundamentals A 4 volume Set written by John R Thome and published by World Scientific. This book was released on 2018-03-13 with total page 1460 pages. Available in PDF, EPUB and Kindle. Book excerpt: Set III of this encyclopedia is a new addition to the previous Sets I and II. It contains 26 invited chapters from international specialists on the topics of numerical modeling of two-phase flows and evaporation, fundamentals of evaporation and condensation in microchannels and macrochannels, development and testing of micro two-phase cooling systems for electronics, and various special topics (surface wetting effects, microfin tubes, two-phase flow vibration across tube bundles). The chapters are written both by renowned university researchers and by well-known engineers from leading corporate research laboratories. Numerous 'must read' chapters cover the fundamentals of research and engineering practice on boiling, condensation and two-phase flows, two-phase heat transfer equipment, electronics cooling systems, case studies and so forth. Set III constitutes a 'must have' reference together with Sets I and II for thermal engineering researchers and practitioners.
Download or read book Advances in Heat Transfer written by and published by Academic Press. This book was released on 2022-10-21 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Heat Transfer, Volume 54 in this comprehensive series, highlights new advances in the field, with this new volume presenting interesting chapter written by an international board of authors. Updates to this new release include chapters on Thermal Convection Studies at the University of Minnesota and Turbulent passive scalar transport in smooth wall-bounded flows: recent advances. Includes the authority and expertise of leading contributors from an international board of authors Presents the latest release in Advances in Heat Transfer series Provides a comprehensive approach, highlighting new advances in the field
Download or read book Two Phase Heat Transfer Enhancement written by Sujoy Kumar Saha and published by Springer. This book was released on 2019-07-04 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Brief concerns heat transfer and pressure drop in heat transfer enhancement for boiling and condensation. The authors divide their topic into six areas: abrasive treatment and coatings, combined structured and porous surfaces, basic principles of boiling mechanism, vapor space condensation, convective vaporization, and forced condensation inside tubes. Within this framework, the book examines range of specific phenomena including abrasive treatment, open grooves, 3D cavities, etched surfaces, electroplating, pierced 3D cover sheets, attached wire and screen promoters, non-wetting coatings, oxide and ceramic coatings, porous surfaces, structured surfaces (integral roughness), combined structured and porous surfaces, composite surfaces, single-tube pool boiling tests, theoretical fundamentals like liquid superheat, effect of cavity shape and contact angle on superheat, entrapment of vapor in cavities, nucleation at a surface cavity, effect of dissolved gases, bubble departure diameter, bubble dynamics, boiling hysteresis and orientation effects, basic principles of boiling mechanism, visualization and mechanism of boiling in subsurface tunnels, and Chien and Webb parametric boiling studies.
