Download or read book A Transient Model for Minimum Film Boiling Point in Subcooled Film Boiling written by Laung-Kuang Toby Wu and published by . This book was released on 1987 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Low Speed Forced Flow and Subcooling on the Minimum Film Boiling Wall Superheat of Small Spheres written by Saeed Rezakhany and published by . This book was released on 1983 with total page 666 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heat Transfer in Stable Film Boiling written by LeRoy Alton Bromley and published by . This book was released on 1949 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On the Film Boiling from Small Spheres and the Use of Minimum Film Boiling Temperature in the Modeling of Vapor Explosions written by Chunkuan Shih and published by . This book was released on 1978 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Understanding the Minimum Film Boiling Temperature in Two phase Flow written by Juliana Pacheco Duarte and published by . This book was released on 2018 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: The post-critical heat flux (post-CHF) heat transfer is a complex two-phase flow phenomenon divided in two regions: a so-called 'transition boiling' regime characterized by the rapid degradation of heat transfer from a heated surface to a liquid/vapor mixture, and a so-called 'stable film boiling' regime characterized by heat transfer from the heated surface to the vapor. The limit between these two regimes is usually referred as the minimum film boiling temperature (TMFB), and has been interpreted as a temperature from which the liquid no longer can contact the heated surface. To better understand these phenomena, experiments were performed at LWR conditions in the High Pressure Heat Transfer Facility at the University of Wisconsin-Madison. These experiments and subsequent prototypic experiments from the KATHY facility, in Germany, contribute to the limited experimental database on this topic. KATHY data were collected under BWR conditions during Anticipate Transient Without Scram that leads to cycles of dryout and rewet events and ultimately to a failure to rewet of at least one thermocouple. The data were analyzed using a 2D inverse heat transfer computational tool to obtain the surface heat fluxes and temperatures during post-CHF. It was observed that the transition to the film boiling heat transfer regime is a hydrodynamic mechanism dependent on both the pressure and the mass flux, while the local quality affects the mechanism of film formation between a film dryout at high qualities and bubbles coalescence at low qualities. The homogeneous nucleation temperature, which is a thermodynamic mechanism, acts as a lower bound for this transition temperature. The analysis also quantifies different transient boiling curves for flow regimes that differ qualitatively and quantitatively from the typical boiling curve considered in steady-state two-phase heat transfer analysis. The results provide insights into boiling heat transfer and they can change the way we currently model the two-phase post-CHF.
Download or read book Transient Film Boiling on a Horizontal Cylindrical Surface in a Subcooled Liquid written by Howard Hong-Yuang Yen and published by . This book was released on 1968 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Minimum Film boiling Heat Flux in Vertical Flow of Liquid Nitrogen written by Frederick F. Simon and published by . This book was released on 1968 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Transient forced Convection Film Boiling on an Isothermal Flat Plate written by H. R. Nagendra and published by . This book was released on 1971 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: An approach for the solution of transient-forced convection film boiling on an isothermal flat plate using the boundary layer model is developed. The similarity variables are used to convert the governing partial differential equations to ordinary ones. The results of numerical solutions of these ordinary equations indicate that the transient process can be classified as one-dimensional conduction, intermediate, and the steady state regions. The time required for the one-dimensional conduction and the time necessary to attain a steady state condition are obtained. The influence of interfacial shear is seen to be negligible while the Prandtl Number and the ratio (C sub p delta T divided by h sub fg times Pr) have major influence. The use of local similarity approximations for the intermediate regime facilitates prediction of complete boundary layer growth. Using the ratio of time at any instant to the steady state time as abscissa, the curves representing the boundary layer growth can be merged into a single mean curve within 5 percent. Further, the analysis shows that the average rate of heat transfer during transient is 50 to 100 percent higher than those at steady state. The average rate of vapor convected away is 10 to 15 percent lower than at steady state while the average rate of accumulation to form the vapor layer is 1 to 14 times larger. Further, the total heat transferred during transient increases and the evaporation decreases for increasing values of C sub p delta T divided by h sub fg times Pr.
Download or read book The Effect of the Radiative Heat Transfer on Subcooled Film Boiling written by Sunchai Nilsuwankosit and published by . This book was released on 1997 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Subcooled Pool Film Boiling of Aqueous Surfactant Solutions from Small Spheres written by Susan E. Bayley and published by . This book was released on 1993 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Film Boiling of Flowing Subcooled Liquids written by Eugene Izoard Motte and published by . This book was released on 1954 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Film Boiling of Flowing Subcooled Liquids Thesis written by Eugene Izoard Motte and published by . This book was released on 1954 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Effect of Liquid Subcooling Initial Surface Temperature and Surface Properties on the Minimum Film Boiling Temperature written by Valerie Fudurich and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental test facility has been designed and constructed with the purpose of performing high-temperature pool boiling experiments for vertical cylinder geometry. The heat transfer regime of interest is high temperature film boiling and the transition point at the minimum film boiling temperature, Tmin. The large superheat temperature and heat flux are able to sustain a vapor blanket that prevents the bulk liquid from direct physical contact with the heated surface. Experiments focused on varying the initial rod temperature, liquid subcooling, and surface conditions through oxidation to study their influence on Tmin and the boiling curve. These initial conditions were varied for two series of quenching experiments. The first varied the rod and bath temperatures and the second held these temperatures constant for sequential tests to build an oxide layer. A stainless steel cylindrical rod fitted with embedded thermocouples was heated to a temperature well in the film boiling regime and quickly inserted in an otherwise quiescent pool of distilled water. The superheated surface is quenched when the liquid comes into contact after the collapse of the vapor film. The embedded thermocouples were connected to a data acquisition system to record temperature-time traces. Additionally, video was recorded during the quenching process for visualization of the vapor film. Quenching curves were used to calculate the heat flux and construct the boiling curve. The minimum film boiling temperature was calculated by finding the minimum heat flux associated with Tmin. Data reduction was performed by using an inverse heat conduction code (DATARH) to calculate surface temperature and heat flux. It was found that, similar to the majority of previous research, the liquid subcooling strongly influences the minimum film boiling temperature. In addition, the vapor film thickness and the behavior of the liquid-vapor boundary layer is closely linked to the liquid subcooling. The initial surface temperature had little effect on Tmin compared to the large effect of liquid subcooling. The duration of the entire quench process however, was extended when the initial surface temperature was increased. A second series of tests to investigate the effects of oxidation were also undertaken. When several tests were completed in succession without restoring the rod surface to bare conditions, Tmin changed subtly after the first oxidized test. The effect did not become more pronounced with subsequent tests. However when the rods were given multiple hours to oxidize, Tmin did not stay constant. This suggests that although stainless steel is resistant to changes to the oxide layer during short term heat cycles, extended heat influences the oxide layer. The current findings were used to observe the effectiveness of a correlation produced by Peterson and Bajorek. As the surface conditions of the oxidized rod were unable to be quantified, the basic form of the correlation was used. Most experimental data was predicted within ±10% by the correlation.
Download or read book Experimental Observations of Transient Boiling of Subcooled Water and Alcohol on a Horizontal Surface written by Robert W. Graham and published by . This book was released on 1965 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
