Download or read book An Investigation of Bubble Departure in Subcooled Flow Boiling written by Brian J. Stumm and published by . This book was released on 1993 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: "A summary of the major theoretical models available for departure diameter prediction in sub-cooled flow boiling is presented. A new model is developed to predict the forces acting on a bubble at the instance of departure by introducing a control volume approach for the front and the rear halves of the bubble. The predictions from the model are compared with experimental data obtained in the Thermal Analysis Laboratory in the Mechanical Engineering Department at Rochester Institute of Technology. Two competing mechanisms are identified as being responsible for bubble departure. To obtain clear evidence of the dominate mechanism, high speed photography is recommended in future work in this area."--Abstract.
Download or read book Investigation of Inertia Controlled Bubble Departure Mechanism in Subcooled Flow Boiling Using High Speed Photography written by Viktor R. Mizo and published by . This book was released on 1995 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: "A summary of important theoretical models available for bubble growth and departure behavior in flow boiling is presented. Experimental bubble growth rate curves under sub-cooled flow boiling conditions are obtained in the Thermal Analysis Laboratory in the Mechanical Engineering Department at the Rochester Institute of Technology utilizing high-speed photography. The effects of flow rate, sub-cooling, heater surface temperature, and cavity size are investigated, and specific trends observed in the bubble growth rate behavior are discussed. The growth rates in flow boiling are compared with the ones for pool boiling, and a need for an improved model for predicting bubble growth rates in flow boiling is established. The new model based on a control volume approach for the front and rear halves of a bubble developed earlier in the Thermal Analysis Lab at RIT is extended to include the inertia forces acting on a growing bubble. The predictions from the model are compared to the experimental data and are found to agree within an average absolute error of 7.45 %. The mechanism of the actual bubble departure from the heater surface is discussed, and suggestions for future work in the area are outlined."--Abstract.
Download or read book Convective Boiling and Condensation written by John G. Collier and published by Clarendon Press. This book was released on 1994-05-19 with total page 646 pages. Available in PDF, EPUB and Kindle. Book excerpt: * Third edition of a well-known and well established text both in industry and for teaching * Fully up-to-date and includes extra problems This book is an aid to heat exchanger design written primarily for design and development engineers in the chemical process, power generation, and refrigeration industries. It provides a comprehensive reference on two-phase flows, boiling, and condensation. The text covers all the latest advances like flows over tube bundles and two-phase heat transfer regarding refrigerants and petrochemicals. Another feature of this third edition is many new problems at chapter ends to enhance its use as a teaching text for graduate and post-graduate courses on two-phase flow and heat transfer. - ;This book is written for practising engineers as a comprehensive reference on two-phase flows, boiling, and condensation. It deals with methods for estimating two-phase flow pressure drops and heat transfer rates. It is a well-known reference book in its third edition and is also used as a text for advanced university courses. Both authors write from practical experience as both are professional engineers. -
Download or read book Bubble Behavior in Subcooled Flow Boiling on Surfaces of Variable Wettability written by Emily W. Tow and published by . This book was released on 2012 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: Flow boiling is important in energy conversion and thermal management due to its potential for very high heat fluxes. By improving understanding of the conditions leading to bubble departure, surfaces can be designed that increase heat transfer coefficients in flow boiling. Bubbles were visualized during subcooled nucleate flow boiling of water on a surface of variable wettability. Images obtained from the videos were analyzed to find parameters influencing bubble size at departure. A model was developed relating the dimensions of the bubble at departure to its upstream and downstream contact angles based on a rigid-body force balance between momentum and surface tension and assuming a skewed truncated spherical bubble shape. Both experimental and theoretical results predict that bubble width and height decrease with increasing flow speed and that the width increases with the equilibrium contact angle. The model also predicts that the width and height increase with the amount of contact angle hysteresis and that the height increases with equilibrium contact angle, though neither of these trends were clearly demonstrated by the data. Several directions for future research are proposed, including modifications to the model to account for deviations of the bubbles from the assumed geometry and research into the parameters controlling contact angle hysteresis of bubbles in a flow. Additionally, observations support that surfaces with periodically-varying contact angle may prevent film formation and increase the heat transfer coefficients in both film and pool boiling.
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 Multiphase Flow Dynamics 3 written by Nikolay Ivanov Kolev and published by Springer Science & Business Media. This book was released on 2011-09-25 with total page 683 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multi-phase flows are part of our natural environment such as tornadoes, typhoons, air and water pollution and volcanic activities as well as part of industrial technology such as power plants, combustion engines, propulsion systems, or chemical and biological industry. The industrial use of multi-phase systems requires analytical and numerical strategies for predicting their behavior. .In its fourth extended edition the successful monograph package “Multiphase Flow Daynmics” contains theory, methods and practical experience for describing complex transient multi-phase processes in arbitrary geometrical configurations, providing a systematic presentation of the theory and practice of numerical multi-phase fluid dynamics. In the present third volume methods for describing of the thermal interactions in multiphase dynamics are provided. In addition a large number of valuable experiments is collected and predicted using the methods introduced in this monograph. In this way the accuracy of the methods is revealed to the reader. This fourth edition includes various updates, extensions, improvements and corrections. "The literature in the field of multiphase flows is numerous. Therefore, it is very important to have a comprehensive and systematic overview including useful numerical methods. The volumes have the character of a handbook and accomplish this function excellently. The models are described in detail and a great number of comprehensive examples and some cases useful for testing numerical solutions are included. These two volumes are very useful for scientists and practicing engineers in the fields of technical thermodynamics, chemical engineering, fluid mechanics, and for mathematicians with interest in technical problems. Besides, they can give a good overview of the dynamically developing, complex field of knowledge to students. This monograph is highly recommended,” BERND PLATZER, ZAAM In the present third volume methods for describing of the thermal interactions in multiphase dynamics are provided. In addition a large number of valuable experiments is collected and predicted using the methods introduced in this monograph. In this way the accuracy of the methods is revealed to the reader. This fourth edition includes various updates, extensions, improvements and corrections. "The literature in the field of multiphase flows is numerous. Therefore, it is very important to have a comprehensive and systematic overview including useful numerical methods. The volumes have the character of a handbook and accomplish this function excellently. The models are described in detail and a great number of comprehensive examples and some cases useful for testing numerical solutions are included. These two volumes are very useful for scientists and practicing engineers in the fields of technical thermodynamics, chemical engineering, fluid mechanics, and for mathematicians with interest in technical problems. Besides, they can give a good overview of the dynamically developing, complex field of knowledge to students. This monograph is highly recommended,” BERND PLATZER, ZAAM
Download or read book Multiphase Flow Dynamics 2 written by Nikolay Ivanov Kolev and published by Springer Science & Business Media. This book was released on 2005-08-15 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multi-phase flows are part of our natural environment such as tornadoes, typhoons, air and water pollution and volcanic activities as well as part of industrial technology such as power plants, combustion engines, propulsion systems, or chemical and biological industry. The industrial use of multi-phase systems requires analytical and numerical strategies for predicting their behavior. In its third extended edition this book contains theory, methods and practical experience for describing complex transient multi-phase processes in arbitrary geometrical configurations. This book provides a systematic presentation of the theory and practice of numerical multi-phase fluid dynamics. In the present second volume the mechanical and thermal interactions in multiphase dynamics are provided. This third edition includes various updates, extensions, improvements and corrections.
Download or read book Analysis of Heat Transfer Burnout Pressure Drop and Density Data for High pressure Water written by W. H. Jens and published by . This book was released on 1955 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Investigation of Subcooled Flow Boiling Using Synchronized High Speed Video Infrared Thermography and Particle Image Velocimetry written by Bren Andrew Phillips and published by . This book was released on 2014 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: Subcooled flow boiling of water was experimentally investigated using high-speed video (HSV), infrared (IR) thermography, and particle image velocimetry (PIV) to generate a unique database of synchronized data. HSV allowed measurement of the bubble departure diameter. IR thermography allowed measurement of wall superheat (local distribution and surface-averaged values), heat transfer coefficient, nucleation site density, and bubble frequency. Particle image velocimetry allowed for the measurement of velocity profiles in the liquid phase for single bubble nucleation events. The tests were performed at pressures of 1.05, 1.5, and 2.0 bar and at subcoolings of 5, 10, and 15 °C. The mass flux values explored were 150-1250 kg/m2/s. The heat flux values explored were 100-1600 kW/m2. As expected, the heat transfer coefficients increased with increasing mass flux in the single-phase convection and partial boiling regions, and converged to a fully-developed boiling curve for high heat fluxes. The bubble departure diameter decreased with increasing mass flux and decreasing heat flux; in accordance with Sugrue's model. The nucleation site density increased with increasing superheat and decreasing mass flux, as predicted by Kocamustafaogullari and Ishii's model. The nucleation site density models under-predicted the nucleation site density for a given wall superheat. Wait time and frequency models did not reproduce the data accurately, and underestimated wait time by an order of magnitude. A new mechanistic model for calculating the wait time was developed that split the wall heat flux into the component that is transferred to the fluid, and the component that is transferred as sensible heat into the heater wall. Significant localized cooling was observed underneath bubbles sliding along the wall after departure from a nucleation site, an effect which should be considered in advanced models of subcooled flow boiling. The sliding bubble thermal effects were found to be insensitive to system conditions and were limited by the thermal conduction within the substrate. Bubble growth front velocities, and regions of flow influence of departing bubbles were measured with PIV. The database generated in this project can be used to inspire or validate mechanistic models and/or CFD simulations of subcooled flow boiling heat transfer.
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
Download or read book Direct Contact Heat Transfer written by Frank Kreith and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: to increase the use of direct contact processes, the National Science Foundation sup ported a workshop on direct contact heat transfer at the Solar Energy Research Insti tute in the summer of 1985. We served as organizers for this workshop, which em phasized an area of thermal engineering that, in our opinion, has great promise for the future, but has not yet reached the point of wide-spread commercial application. Hence, a summary of the state of knowledge at this point is timely. The workshop had a dual objective: 1. To summarize the current state of knowledge in such a form that industrial practi tioners can make use of the available information. 2. To indicate the research and development needed to advance the state-of-the-art, indicating not only what kind of research is needed, but also the industrial poten tial that could be realized if the information to be obtained through the proposed research activities were available.
Download or read book Bubble Wake Dynamics in Liquids and Liquid Solid Suspensions written by Liang-Shih Fan and published by Butterworth-Heinemann. This book was released on 2013-10-22 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is devoted to a fundamental understanding of the fluid dynamic nature of a bubble wake, more specifically the primary wake, in liquids and liquid-solid suspensions, an dto the role it plays in various important flow phenomena of multiphase systems. Examples of these phenomena are liquid/solids mixing, bubble coalescence and disintergration, particle entrainment to the freeboard, and bed contraction.
Download or read book Heat Transfer in Boiling written by Erich Hahne and published by . This book was released on 1977 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book VDI Heat Atlas written by VDI Gesellschaft and published by Springer Science & Business Media. This book was released on 2010-07-21 with total page 1608 pages. Available in PDF, EPUB and Kindle. Book excerpt: For more than 50 years, the Springer VDI Heat Atlas has been an indispensable working means for engineers dealing with questions of heat transfer. Featuring 50% more content, this new edition covers most fields of heat transfer in industrial and engineering applications. It presents the interrelationships between basic scientific methods, experimental techniques, model-based analysis and their transfer to technical applications.
Download or read book Investigation of Heat Transfer in Subcooled Flow Boiling written by Jinfeng Wu and published by . This book was released on 2001 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Convective Flow Boiling written by John C. Chen and published by CRC Press. This book was released on 2019-08-16 with total page 776 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book An Investigation of Subcooled Flow Boiling with Emphasis on Its Initiation written by Khosrow Nourmohammadi and published by . This book was released on 1980 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:
