Download or read book Evaluation of Droplet Deposition Coefficient and Entrainment Rate in Annular Two Phase Flow vertical Flow written by Chee Hwa Danny Yeo and published by . This book was released on 1998 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Droplets Deposition Coefficient and Entrainment Rate in Annular Two phase Flow in Vertical Round Tube written by Yiak Mong Yeoh and published by . This book was released on 1998 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Annular Two Phase Flow written by Geoffrey Hewitt and published by Elsevier. This book was released on 2013-10-22 with total page 327 pages. Available in PDF, EPUB and Kindle. Book excerpt: Annular Two-Phase Flow presents the wide range of industrial applications of annular two-phase flow regimes. This book discusses the fluid dynamics and heat transfer aspects of the flow pattern. Organized into 12 chapters, this book begins with an overview of the classification of the various types of interface distribution observed in practice. This text then examines the various regimes of two-phase flow with emphasis on the regions of occurrence of the annular flow regime. Other chapters consider the single momentum and energy balances, which illustrate the differences and analogies between single- and two-phase flows. This book discusses as well the simple modes for annular flow with consideration to the calculation of the profile of shear stress in the liquid film. The final chapter deals with the techniques that are developed for the measurement of flow pattern, entrainment, and film thickness. This book is a valuable resource for chemical engineers.
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 Entrainment and Deposition Rates of Droplets in Annular Two phase Flow PWR BWR written by and published by . This book was released on 1983 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The droplet entrainment from a liquid film is important to the mass, momentum, and energy transfer processes in annular two-phase flow. For example, the amount of entrainment as well as the rate of entrainment significantly affect the occurrences of the dryout, whereas the post CHF heat transfer depends strongly on the entrainment and droplet sizes. Despite the importance of the entrainment rate, there have been no satisfactory correlations available in the literature. In view of these, correlations for entrainment rate covering both entrance region and equilibrium region have been developed from a simple model in collaboration with data. Results show that the entrainment rate varies considerably in the entrainment development region, however, at a certain distance from an inlet it attains an equilibrium value. A simple approximate correlation has been obtained for the equilibrium state where entrainment rate and deposition rate becomes equal. The result indicates that the equilibrium entrainment rate is proportional to Weber number based on the hydraulic diameter of a tube.
Download or read book Mechanism and Correlation of Droplet Entrainment and Deposition in Annular Two phase Flow written by Isao Kataoka and published by . This book was released on 1982 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Film Entrainment and Drop Deposition for Two phase Flow written by A. Koestel and published by . This book was released on 1980 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nuclear Regulatory Commission Issuances written by U.S. Nuclear Regulatory Commission and published by . This book was released on 1979 with total page 950 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Drop Concentration on Deposition in Vertical Annular Two phase Flow written by Kent James Hay and published by . This book was released on 1994 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Droplet Entrainment Correlation for High Pressure Annular Two phase Flow written by and published by . This book was released on 1996 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: The amount of entrainment in annular flow is essential to predict the point of dryout. Most of the entrainment correlations available in the literature are obtained from air-water low pressure data. However many important industrial applications involve high pressure annular flows. There are very few correlations applicable in this range and they are solely based on empirical data fits. Comparing the low pressure entrainment data of Cousins and Hewitt (1968) and the high pressure data of Keeys et. al. (1970) and Wurtz (1978) with existing correlations, the agreement at high pressure is generally poor, except for the empirical correlation of Nigmatulin and Krushenok (1989) which depends on a Weber number that includes the droplet concentration. We propose a new semi-mechanistic entrainment correlation for fully developed annular flow conditions: E = (0.9642)/(1 + (3836/We{sub C})). It is developed based on the droplet continuity equation and the entrainment rate model of Dallman et. al. (1979). This model is then modified to introduce a Weber number that includes the droplet concentration, We{sub C}. This Weber number is shown to scale the available high and low pressure air-water and steam-water data better than the other definitions. Because the new correlation is based on a model of entrainment rate it may be used as a starting point in the development of a correlation for this process applicable to high pressure water-steam annular flows. A correlation is suggested pending validation with high pressure entrainment rate data. 12 refs., 11 figs.
Download or read book A model for the droplet deposition rate in horizontal annular two phase flow written by N. S. Wilkes and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Entrainment Rate of Droplets in the Ripple annular Regime for Small Vertical Tubes written by and published by . This book was released on 1998 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two-fluid model predictions of film dryout in annular flow are limited by the uncertainties in the constitutive relations for the entrainment rate of droplets from the liquid film. The main cause of these uncertainties is the lack of separate effects experimental data in the range of the operating conditions in nuclear power reactors. Air/water and Freon-113 entrainment rate data have been obtained in 10 mm tubes using the film extraction technique. These experiments have been scaled to approach high pressure steam-water flow conditions. The effects of surface tension and density ratio, missing from most previous data sets, have been systematically tested. The entrainment rate mechanism is assumed to be a Kelvin-Helmholtz instability. Based on this analysis and two previous correlations, a new correlation is proposed that is valid for low viscosity fluids in small ducts in the ripple annular regime.
Download or read book Atomization and Deposition Rates in Vertical Annular Two phase Flow written by Suzanne A. Schadel and published by . This book was released on 1994 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Pressure Annular Two phase Flow in a Narrow Duct Part 1 Local Measurements in the Droplet Field and Part 2 Three field Modeling written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In Part 1, detailed measurements were made in a high pressure, adiabatic (boiled at the inlet) annular flow in a narrow, high aspect ratio duct using a gamma densitometer, hot-film anemometer and high-speed video photography. Measurements of void fraction, droplet frequency, velocity, drop size, and interfacial area concentration have been made to support the three field computational capability. An important aspect of this testing is the use of a modeling fluid (R-134a) in a vertical duct which permits visual access in annular flow. This modeling fluid accurately simulates the low liquid-to-vapor density ratio of steam-water flows at high pressures. These measurements have been taken in a narrow duct of hydraulic diameter 4.85 mm, and a cross-section aspect ratio of 22.5. However, the flow displays profiles of various shapes not only in the narrow dimension, but also in the width dimension. In particular, the shape of the droplet profiles depends on the entrained droplet flux from the edges in the vapor core. The average diameter from these profiles compare well with the models developed in the literature. Interfacial area concentration for these low density ratio flows is higher than the highest concentration reported for air-water flows. Video records show that along with the bow-shaped waves, three-dimensional[lambda]-shaped waves appear in annular flows for high flow rates. Part 2 outlines the development of a three-field modeling approach in annular flow and the predictive capability of an analysis code. Models have been developed here or adapted from the literature for the thin film near the wall as well as the droplets in the vapor core, and have been locally applied in a fully developed, two-phase adiabatic boiling annular flow in a duct heated at the inlet at high pressure. Numerical results have been obtained using these models that are required for the closure of the continuity and momentum equations. The two-dimensional predictions are compared with local void fraction and droplet velocity (using a hot film anemometer), and average void fraction (using gamma densitometry) for a refrigerant fluid flowing in a narrow vertical duct with a cross-section aspect ratio of 22.5. Predicted results match the experimental data well for high void fraction annular flows, validating the overall modeling approach.
Download or read book Droplet Sizes Dynamics and Deposition in Vertical Annular Flow written by J. C. B. Lopes and published by . This book was released on 1985 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transient Non equilibrium Two phase Flow written by Masahiro Kawaji and published by . This book was released on 1984 with total page 524 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Experimental and Analytical Investigation of Entrainment Rates for Downward Annular Mist Two phase Flow in Pipes and Downstream of a Localized Contraction written by Kim Ann Shollenberger and published by . This book was released on 1994 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:
