Download or read book Cavitation Inception in Separated Flows written by Joseph Katz and published by . This book was released on 1981 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: The phenomenon of cavitation was studied on four axisymmetric bodies whose boundary layers underwent a laminar separation and a subsequent turbulent reattachment. The conditions for cavitation inception and desinence were determined and several holograms were recorded just prior to and at the onset of cavitation. The population of microbubbles and the nature of the subsequent development of visible cavitation was determined from the reconstructed image. Cavitation inception occurred in the turbulent shear layer downstream of the transition region. When the separation zone was large the inception region was located within the most developed section of the mixing layer but upstream of the reattachment zone. When the separation region was small inception occurred close to the reattachment zone but still detached from the body surface. A comparison between the surface minimum pressure and the cavitation inception indices also indicated that inception could not occur near the surface of the bodies having a large separation region. The appearance of visible cavities was preceded by the appearance of a cluster of microbubbles only in the cavitation inception region. The nuclei population in the other sections of the flow field remained fairly uniform. This observation supports the assumption that cavitation is initiated from microscopic free stream nuclei.
Download or read book Recent Developments in Cavitation Mechanisms written by Seiichi Washio and published by Woodhead Publishing. This book was released on 2014-08-28 with total page 287 pages. Available in PDF, EPUB and Kindle. Book excerpt: How does cavitation start? Presently, the nucleus theory provides the answer to this fundamental question. However the idea of nuclei contains inaccuracies that cannot be rationalized. Recent Developments in Cavitation Mechanisms discusses the uncertainties surrounding the nucleus theory, and proposes another theory of cavitation mechanism. Characteristically, the new theory is based on recent discoveries of cavity generation phenomena in separating flows. This book consists of chapters that introduce topics such as unsoundness of cavitation nuclei, and phenomena of cavity generation on walls of flow separation in hydraulic oil and water flows. Subsequent chapters cover the mechanism of cavity generation at point of flow separation, nucleation by contact motion between solids in liquid and a proposal of new cavitation mechanism based on flow separation and solid contact. The final chapters present the demonstration of a new mechanism in the hydraulic poppet valve and a concluding summary. proposes a new mechanism of cavitation inception in liquid machines describes in detail phenomena of cavity generation at point of flow separation recently discovered by the author discusses peculiar properties of flow separation as cause of cavity generation presents abundant experimental data of incipient cavitation obtained with high resolution of time and space provides supplementary materials of slow motion videos that can help understand the very rapid and minute phenomena of cavity generation which has been discovered by the author and will be still unfamiliar to many
Download or read book A Theory for Cavitation Inception in a Flow Having Laminar Separation written by B. R. Parkin and published by . This book was released on 1979 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt: An approximate theory is developed to predict onset of cavitation on hemispherical head forms for Reynolds numbers at which laminar separation is known to occur. Fairly good agreement is obtained between cavitation inception (or desinence) trends recently measured and the present theory which is based upon first principles as far as possible. Moreover, the observed occurrence of a lowest speed for 'bubble-ring' cavitation, which is the only cavitation form considered, and the range of 'cutoff' speeds predicted by the present asymptotic theory show very encouraging agreement. Like the experiments, this theory suggests that the cutoff speed and its accompanying cutoff cavitation number can also depend on water temperature, provided that the initial size attributed to a 'typical' spherical free-stream air bubble nucleus also varies with temperature. At 80 F (26.6 C) it is found that the typical nucleus from which bubble-ring cavitation orginates has a radius of about seven microns. At higher temperatures the nucleus radius decreases from this value while at lower temperatures the initial radius exceeds the value noted. It is also found that: the onset cavitation number should be less than the magnitude of the pressure coefficient at the laminar separation point; and that the cavitation number increases with free-stream velocity. As long as there is an appreciable concentration of dissolved air in the water, it is also found that in agreement with experiment, the onset of bubble-ring cavitation is practically independent of air content.
Download or read book Fundamentals of Cavitation written by Jean-Pierre Franc and published by Springer Science & Business Media. This book was released on 2006-01-22 with total page 321 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book treats cavitation, which is a unique phenomenon in the field of hyd- dynamics, although it can occur in any hydraulic machinery such as pumps, propellers, artificial hearts, and so forth. Cavitation is generated not only in water, but also in any kind of fluid, such as liquid hydrogen. The generation of cavitation can cause severe damage in hydraulic machinery. Therefore, the prevention of cavitation is an important concern for designers of hydraulic machinery. On the contrary, there is great potential to utilize cavitation in various important applications, such as environmental protection. There have been several books published on cavitation, including one by the same authors. This book differs from those previous ones, in that it is both more physical and more theoretical. Any theoretical explanation of the cavitation phenomenon is rather difficult, but the authors have succeeded in explaining it very well, and a reader can follow the equations easily. It is an advantage in reading this book to have some understanding of the physics of cavitation. Therefore, this book is not an introductory text, but a book for more advanced study. However, this does not mean that this book is too difficult for a beginner, because it explains the cavitation phenomenon using many figures. Therefore, even a beginner on cavitation can read and can understand what cavitation is. If the student studies through this book (with patience), he or she can become an expert on the physics of cavitation.
Download or read book Effects of Boundary layer Development on Cavitation Noise and Inception on a Hydrofoil written by and published by . This book was released on 1976 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cavitation Inception Observations on Two Axisymmetric Headforms written by Thomas T. Huang and published by . This book was released on 1977 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cavitation inception observations on two axisymmetric headforms were made in the DTNSRDC 36-inch water tunnel. The results indicate that cavitation inception on a headform with natural flow transition is significantly affected by the air content of the water. The effect of air content on cavitation inception on a headform with laminar separation is less pronounced. Visible cavitation inception never occurred at the locations of minimum static pressure but was observed to occur in the region of natural transition and the separated shear layer following laminar separation. It is concluded that both the viscous effects and cavitatable microbubble population are extremely important parameters governing the cavitation inception process. (Author).
Download or read book Cavitation Inception and Internal Flows with Cavitation written by Allan J. Acosta and published by . This book was released on 1979 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fluid Vortices written by Sheldon Green and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 905 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fluid Vortices is a comprehensive, up-to-date, research-level overview covering all salient flows in which fluid vortices play a significant role. The various chapters have been written by specialists from North America, Europe and Asia, making for unsurpassed depth and breadth of coverage. Topics addressed include fundamental vortex flows (mixing layer vortices, vortex rings, wake vortices, vortex stability, etc.), industrial and environmental vortex flows (aero-propulsion system vortices, vortex-structure interaction, atmospheric vortices, computational methods with vortices, etc.), and multiphase vortex flows (free-surface effects, vortex cavitation, and bubble and particle interactions with vortices). The book can also be recommended as an advanced graduate-level supplementary textbook. The first nine chapters of the book are suitable for a one-term course; chapters 10--19 form the basis for a second one-term course.
Download or read book Cavitation and polyphase flow forum written by Cavitation and Polyphase Flow Forum 1977, New Haven, Conn and published by . This book was released on 1973 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cavitation and Bubble Dynamics written by Christopher E. Brennen and published by Cambridge University Press. This book was released on 2014 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cavitation and Bubble Dynamics deals with fundamental physical processes of bubble dynamics and cavitation for graduate students and researchers.
Download or read book Cavitation Inception written by A. J. Acosta and published by . This book was released on 1985 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: The prediction of cavitation inception in the laboratory is an important aspect of design development and operation of fluid dynamic devices for naval hydrodynamic applications. This report briefly summarizes ten years of laboratory research on cavitation inception in flows past smooth bodies and flows with separation. The instrumentation that has been developed to study these flows is described briefly together with means of counting the concentration of the cavitation nuclei known to be important for inception to occur.
Download or read book Cavitation of Hydraulic Machinery written by S. C. Li and published by World Scientific. This book was released on 2000 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume in the Hydraulic Machinery Book series deals with cavitation and its effects in turbines and pumps. After introducing cavitation and its relation with hydraulic machines, the invited contributors throughout the world review in detail relevant cavitation subjects from fundamental phenomena to various problems and solution measures in hydraulic machines. The authors are internationally recognized experts in their fields.
Download or read book Cavitation and Multiphase Flow Phenomena written by Frederick G. Hammitt and published by McGraw-Hill Companies. This book was released on 1980 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cavitation written by Yves Lecoffre and published by Routledge. This book was released on 2021-10-08 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text deals with the concept that cavitation is the main limitation to the performance of hydraulic components. Topics covered include the vaporization of liquids due to high velocities or pressure fluctuations, and the effects of cavitation on the performances of rotary machinery. One chapter is devoted to cavitation noise which concerns many users, including surface ships and submarines, and the author finishes with some examples of the use of cavitation and subject-specific measuring techniques.
Download or read book Cavitation and Bubble Dynamics written by Phoevos Koukouvinis and published by Elsevier. This book was released on 2021-09-24 with total page 355 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cavitation and Bubble Dynamics: Fundamentals and Applications examines the latest advances in the field of cavitation and multiphase flows, including associated effects such as material erosion and spray instabilities. This book tackles the challenges of cavitation hindrance in the industrial world, while also drawing on interdisciplinary research to inform academic audiences on the latest advances in the fundamentals. Contributions to the book come from a wide range of specialists in areas including fuel systems, hydropower, marine engineering, multiphase flows and computational fluid mechanics, allowing readers to discover novel interdisciplinary experimentation techniques and research results. This book will be an essential tool for industry professionals and researchers working on applications where cavitation hindrance affects reliability, noise, and vibrations. Covers a wide range of cavitation and bubble dynamics phenomena, including shock wave emission, jetting, and luminescence Provides the latest advice about applications including cavitation tunnels, cavitation testing, flow designs to avoid cavitation in pumps and other hydromachinery, and flow lines Describes novel experimental techniques, such as x-ray imaging and new computational techniques
Download or read book A Holographic Study of Cavitation on Axisymmetric Bodies and the Influence of Polymer Additives written by Johannes Hubertus Josefus van der Meulen and published by . This book was released on 1976 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Inception of Cavitation on Hydrofoil Systems written by S. F. Hoerner and published by . This book was released on 1952 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report is concerned with the inception of cavitation in flows about bodies pertinent to hydrofoil systems. The basic phenomenon of cavitation is first discussed with respect to the influence of air content, time of exposure to low pressures, and separated flows. Minimum pressures on airfoils are related to the thickness and lift coefficient; empirical relations involving these parameters are determined which are applicable to a large class of hydrofoil shapes. The use of critical Mach numbers in determining inception values of the cavitation index, particularly for interference flows, is discussed. Cavitation data for several forms of blunt bodies are given. Considering surface roughness elements as blunt bodies, an approximate method of predicting the inception of cavitation on roughness elements in a boundary-layer flow is presented. An empirical formula is derived for the critical speed of hydrofoils and broad conclusions deduced from this study are stated.
