Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
Numerical Modeling Of Bubble Dynamics And Heat Transfer On Flow Boiling Within Microchannels
Download Numerical Modeling Of Bubble Dynamics And Heat Transfer On Flow Boiling Within Microchannels full books in PDF, epub, and Kindle. Read online Numerical Modeling Of Bubble Dynamics And Heat Transfer On Flow Boiling Within Microchannels ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis Numerical Modeling of Bubble Dynamics and Heat Transfer on Flow Boiling Within Microchannels by : Konstantinos Vontas
Download or read book Numerical Modeling of Bubble Dynamics and Heat Transfer on Flow Boiling Within Microchannels written by Konstantinos Vontas and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Flow Boiling in Expanding Microchannels by : Tamanna Alam
Download or read book Flow Boiling in Expanding Microchannels written by Tamanna Alam and published by Springer. This book was released on 2017-06-07 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Brief presents an up to date summary of details of the flow boiling heat transfer, pressure drop and instability characteristics; two phase flow patterns of expanding microchannels. Results obtained from the different expanding microscale geometries are presented for comparison and addition to that, comparison with literatures is also performed. Finally, parametric studies are performed and presented in the brief. The findings from this study could help in understanding the complex microscale flow boiling behavior and aid in the design and implementation of reliable compact heat sinks for practical applications.
Book Synopsis Fluid Flow, Heat Transfer and Boiling in Micro-Channels by : L. P. Yarin
Download or read book Fluid Flow, Heat Transfer and Boiling in Micro-Channels written by L. P. Yarin and published by Springer Science & Business Media. This book was released on 2008-09-19 with total page 487 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Book Synopsis Flow boiling and condensation in microscale channels by : Fabio Toshio Kanizawa
Download or read book Flow boiling and condensation in microscale channels written by Fabio Toshio Kanizawa and published by Springer. This book was released on 2022-04-30 with total page 277 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers aspects of multiphase flow and heat transfer during phase change processes, focusing on boiling and condensation in microscale channels. The authors present up-to-date predictive methods for flow pattern, void fraction, pressure drop, heat transfer coefficient and critical heat flux, pointing out the range of operational conditions that each method is valid. The first four chapters are dedicated on the motivation to study multiphase flow and heat transfer during phase change process, and the three last chapters are focused on the analysis of heat transfer process during boiling and condensation. During the description of the models and predictive methods, the trends are discussed and compared with experimental findings.
Book Synopsis Flow Boiling in Microgap Channels by : Tamanna Alam
Download or read book Flow Boiling in Microgap Channels written by Tamanna Alam and published by Springer. This book was released on 2013-08-26 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Flow Boiling in Microgap Channels: Experiment, Visualization and Analysis presents an up-to-date summary of the details of the confined to unconfined flow boiling transition criteria, flow boiling heat transfer and pressure drop characteristics, instability characteristics, two phase flow pattern and flow regime map and the parametric study of microgap dimension. Advantages of flow boiling in microgaps over microchannels are also highlighted. The objective of this Brief is to obtain a better fundamental understanding of the flow boiling processes, compare the performance between microgap and conventional microchannel heat sinks, and evaluate the microgap heat sink for instabilities and hotspot mitigation.
Book Synopsis Instability in Flow Boiling in Microchannels by : Sujoy Kumar Saha
Download or read book Instability in Flow Boiling in Microchannels written by Sujoy Kumar Saha and published by Springer. This book was released on 2015-09-14 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Brief addresses the phenomena of instability in flow boiling in microchannels occurring in high heat flux electronic cooling. A companion edition in the SpringerBrief Subseries on Thermal Engineering and Applied Science to “Critical Heat Flux in Flow Boiling in Microchannels,” and "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.
Book Synopsis Heat Transfer and Fluid Flow in Minichannels and Microchannels by : Satish Kandlikar
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.
Book Synopsis Flow Boiling Heat Transfer in Narrow Vertical Channels by : Jianyun Shuai
Download or read book Flow Boiling Heat Transfer in Narrow Vertical Channels written by Jianyun Shuai and published by Cuvillier Verlag. This book was released on 2004 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Numerical Simulation and Parametric Study of Bubble Growth During Water and Nanofluid Flow Boiling in a Microchannel by : Arman Khalighi
Download or read book Numerical Simulation and Parametric Study of Bubble Growth During Water and Nanofluid Flow Boiling in a Microchannel written by Arman Khalighi and published by . This book was released on 2015 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, heat dissipation in micro-electronic devices has become a significant limitation for electronics manufacturers. The amount of heat generation per unit area increases as electronic devices become smaller. Micro heat exchangers have become one of the most effective cooling solutions due to their ability to remove a significant amount of heat from small electronic devices. Utilization of two phase flow in these heat exchangers provides an advantage of removing more heat than single phase flow. Microchannel is the most important part of the micro heat exchangers but it is also the most challenging part due to complications of boiling phenomenon in microchannels. Investigating the bubble dynamics inside these channels helps to better understand the bubble behavior to improve current designs of micro heat exchangers. In this study, a numerical model has been used to perform a parametric study of the bubble dynamics inside a microchannel. Effect of Reynolds number, wall superheat, and bubble contact angles has been studied. Effect of using nanofluids as a homogenous mixture to improve heat transfer has been studied, too. The results show a significant change in bubble dynamics by changing the wall superheat and bubble contact angles. On the other hand, changing the Reynolds number and nanofluid concentration were found to be less effective in altering the bubble dynamics.
Book Synopsis Encyclopedia Of Two-phase Heat Transfer And Flow Ii: Special Topics And Applications (A 4-volume Set) by : John R Thome
Download or read book Encyclopedia Of Two-phase Heat Transfer And Flow Ii: Special Topics And Applications (A 4-volume Set) written by John R Thome and published by World Scientific. This book was released on 2015-08-26 with total page 1321 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 'Encyclopedia 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 transfer and adiabatic bubbly and slug flows, the unified annular flow boiling model, flow pattern maps, condensation and boiling theories, new emerging topics, etc.
Book Synopsis Numerical Investigation on the Effect of Gravitational Orientation on Bubble Growth During Flow Boiling in a High Aspect Ratio Microchannel by : Jarryd Potgieter
Download or read book Numerical Investigation on the Effect of Gravitational Orientation on Bubble Growth During Flow Boiling in a High Aspect Ratio Microchannel written by Jarryd Potgieter and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent technological developments, mostly in the fields of concentrated solar power and microelectronics, have driven heat transfer requirements higher than current heat exchangers are capable of producing. Processing power is increasing, while processor size simultaneously decreases and the heat flux requirements of concentrating solar power plants are being driven up by the high temperatures that produce the best thermal efficiency. Heat transfer in microchannels, specifically when utilising flow boiling, has been shown to produce significantly higher heat fluxes than their macro-scale counterparts and could have a large impact on many industrial fields. This high heat transfer characteristic is caused by a number of factors, including the large difference between the sensible and latent heat of the working fluid and the evaporation of a thin liquid film that forms between the microchannel walls and the vapour bubbles. These phenomena occur at incredibly small scales. Flow visualisations, temperature and pressure measurements are therefore difficult to obtain. Many experiments that cover a wide range of microchannel sizes, shapes and orientations, and utilise different working fluids and heat fluxes have been reported. However, the correlations between confined boiling, heat flux and pressure drop have mostly been produced for macro-scale flow. Many different criteria have been developed to distinguish the macro scale from the micro scale, but the general consensus is that macro-scale heat transfer correlations do not perform well when used in the micro scale. Heat transfer correlations are typically created by performing physical experiments over a wide range of parameters and then quantifying the effect that varying these parameters has on the performance of the system. The small scale and high complexity of microchannel-based heat exchangers make visualising the flow within them difficult and inaccurate because both the working fluid and the microchannel walls distort light. The use of numerical modelling via computational fluid dynamics software allows phenomena that occur within the channel to be simulated, which provides valuable insight into how rapid bubble growth affects the surrounding fluid, which can lead to the design of better heat exchangers. This study focused on numerically modelling the growth of a single bubble during the flow boiling of FC-72 in a microchannel with a hydraulic diameter of 0.9 mm and an aspect ratio of 10. The numerical domain was limited to a 10 mm section of the microchannel where bubble nucleation and detachment were observed in an experimental study on a similar microchannel setup. The high cost of 3D simulations was offset by an interface-tracking mesh refinement method, which refined cells not only at the interface, but also a set distance on either side of the interface. To focus on the effects of gravity, a simplified approach is used, which isolates certain phenomena. Density gradients, material roughness and multiple bubble interaction are ignored so that the effects of buoyancy and bubble detachment can be analysed. Simulations are first performed in a 2D section through the centre of the microchannel, and then in the full 3D domain. In both the 3D numerical and experimental cases (Meyer et al., 2020), the bottom heated case had the lowest maximum temperature and the highest heat transfer characteristics, which were influenced by the detachment of the bubble from the heated surface. This observation indicates that the gravitational orientation of the channel can have a significant effect on the heat transfer characteristics of microchannel-based heat exchangers, and that more investigation is required to characterise the extent of this effect.
Book Synopsis Direct Numerical Simulations of Bubbles in Turbulent Flows with Heat Transfer by : Claudio Santarelli
Download or read book Direct Numerical Simulations of Bubbles in Turbulent Flows with Heat Transfer written by Claudio Santarelli and published by Tudpress Verlag Der Wissenschaften Gmbh. This book was released on 2015-08-12 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bubbly flows are essential in many industrial and environmental applications and several methodologies have been employed to investigate the complex phenomena involved. In the present book Direct Numerical Simulations of bubble swarms in channel flow configuration are reported and several cases are presented. The focus is on the mutual interaction between fluid turbulence and bubble dynamics and the impact on the heat transfer in the two-phase mixture. This analysis concerns flow visualizations and quantitative statistical data regarding the fluid as well as the bubbles which can now be used as reference data for model developing and validation.
Book Synopsis Bubble Dynamics and Boiling Heat Transfer by : Samuel Siedel
Download or read book Bubble Dynamics and Boiling Heat Transfer written by Samuel Siedel and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since boiling heat transfer affords a very effective means to transfer heat, it is implemented in numerous technologies and industries ranging from large power generation plants to micro-electronic thermal management. Although having been a subject of research for several decades, an accurate prediction of boiling heat transfer is still challenging due to the complexity of the coupled mechanisms involved. It appears that the boiling heat transfer coefficient is intimately related to bubble dynamics (i.e. bubble nucleation, growth and detachment) as well as factors such as nucleation site density and interaction between neighbouring and successive bubbles. In order to contribute to the understanding of the boiling phenomenon, an experimental investigation of saturated pool boiling from a single or two neighbouring artificial nucleation sites on a polished copper surface has been performed. The bubble growth dynamics has been characterized for different wall superheats and a experimental growth law has been established. The interaction between successive bubbles from the same nucleation site has been studied, showing the bubble shape oscillations that can be caused by these interactions. The forces acting on a growing bubble has been reviewed, and a complete momentum balance has been made for all stages of bubble growth. The curvature along the interface has been measured, and indications concerning the mechanism of bubble detachment have been suggested. The rise of bubble after detachment has been investigated, and the maximum velocity reached before a change of direction has been estimated and compared to existing models from the literature. The interaction between bubbles growing side by side has been studied: the generation and propagation of a wave front during the coalescence of two bubbles has been highlighted. As boiling heat transfer enhancement techniques are being imagined and developed, this study also focuses on the electrohydrodynamic enhancement technique. Boiling experiments have been performed in the presence of electric fields, and their effects on heat transfer and bubble dynamics have been characterized. Although the volume of the bubbles at detachment and the relationship between the bubble frequency and the wall superheat were not affected, the bubble growth curve was modified. The bubbles were elongated in the direction of the electric field, and this elongation was estimated and compared to other studies from the literature. The rising velocity of the bubble was reduced in the presence of electric field, and the behaviour of bubbles growing side by side was modified, the electric field causing the bubbles to repeal each other. These results, obtained in a fully controlled environment, provide compelling evidence that electric fields can be implemented to alter the bubble dynamics and subsequently heat transfer rates during boiling of dielectric fluids.
Book Synopsis Bubble Dynamics in Microchannel Flow Boiling by : David W. Fogg
Download or read book Bubble Dynamics in Microchannel Flow Boiling written by David W. Fogg and published by . This book was released on 2007 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microchannel flow boiling is a very promising solution to the thermal management problem facing the microprocessor industry. In macroscale systems, such as nuclear reactors, flow boiling has been successful in removing large amounts of power. Unfortunately, microscale flows deviate from conventional theory. Large fluctuations in pressure, temperature, and flow distribution are generated by single bubbles due to channel confinement.
Book Synopsis Numerical Modeling of the Heat Transfer Controlled Bubble Growth in Nucleate Boiling by : Wei Zhao
Download or read book Numerical Modeling of the Heat Transfer Controlled Bubble Growth in Nucleate Boiling written by Wei Zhao and published by . This book was released on 2001 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Two-Phase Flow, Boiling, and Condensation by : S. Mostafa Ghiaasiaan
Download or read book Two-Phase Flow, Boiling, and Condensation written by S. Mostafa Ghiaasiaan and published by Cambridge University Press. This book was released on 2017-01-11 with total page 1322 pages. Available in PDF, EPUB and Kindle. Book excerpt: Providing a comprehensive introduction to the fundamentals and applications of flow and heat transfer in conventional and miniature systems, this fully enhanced and updated edition covers all the topics essential for graduate courses on two-phase flow, boiling, and condensation. Beginning with a concise review of single-phase flow fundamentals and interfacial phenomena, detailed and clear discussion is provided on a range of topics, including two-phase hydrodynamics and flow regimes, mathematical modeling of gas-liquid two-phase flows, pool and flow boiling, flow and boiling in mini and microchannels, external and internal-flow condensation with and without noncondensables, condensation in small flow passages, and two-phase choked flow. Numerous solved examples and end-of-chapter problems that include many common design problems likely to be encountered by students, make this an essential text for graduate students. With up-to-date detail on the most recent research trends and practical applications, it is also an ideal reference for professionals and researchers in mechanical, nuclear, and chemical engineering.
Book Synopsis Modeling and Predicting Heat Transfer Coefficients for Flow Boiling in Microchannels by : Ari Bard
Download or read book Modeling and Predicting Heat Transfer Coefficients for Flow Boiling in Microchannels written by Ari Bard and published by . This book was released on 2021 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: Flow boiling has become a reliable mode of adapting to larger power densities and greater functions because it is able to utilize both the latent and sensible heat contained within a specified coolant. There are currently few available tools proven reliable when predicting heat transfer coefficients during flow boiling in microchannels. The most popular methods rely on semi-empirical correlations derived from experimental data but can only be applied to a narrow subset of testing conditions. This study will use multiple data science methods to accurately predict the heat transfer coefficient during flow boiling in micro-channels on a database consisting of 16,953 observations collected across 50 experiments using 12 working fluids. The support vector machine model performed best, with a Mean Absolute Percentage Error (MAPE) of 11.3%. The heat flux, vapor-only Froude number, and quality proved to be especially significant variables across 90% of over 110 different models.
