Download or read book Vortex Rings and Jets written by Daniel T. H. New and published by Springer. This book was released on 2015-03-26 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book, recent developments in our understanding of fundamental vortex ring and jet dynamics will be discussed, with a view to shed light upon their near-field behaviour which underpins much of their far-field characteristics. The chapters provide up-to-date research findings by their respective experts and seek to link near-field flow physics of vortex ring and jet flows with end-applications in mind. Over the past decade, our knowledge on vortex ring and jet flows has grown by leaps and bounds, thanks to increasing use of high-fidelity, high-accuracy experimental techniques and numerical simulations. As such, we now have a much better appreciation and understanding on the initiation and near-field developments of vortex ring and jet flows under many varied initial and boundary conditions. Chapter 1 outlines the vortex ring pinch-off phenomenon and how it relates to the initial stages of jet formations and subsequent jet behaviour, while Chapter 2 takes a closer look at the behaviour resulting from vortex ring impingement upon solid boundaries and how the use of a porous surface alters the impingement process. Chapters 3 and 4 focus upon the formation of synthetic jets from vortex ring structures experimentally and numerically, the challenges in understanding the relationships between their generation parameters and how they can be utilized in flow separation control problems. Chapter 5 looks at the use of imposing selected nozzle trailing-edge modifications to effect changes upon the near-field dynamics associated with circular, noncircular and coaxial jets, with a view to control their mixing behaviour. And last but not least, Chapter 6 details the use of unique impinging jet configurations and how they may lend themselves towards greater understanding and operating efficacies in heat transfer problems. This book will be useful to postgraduate students and researchers alike who wish to get up to speed regarding the latest developments in vortex ring and jet flow behaviour and how their interesting flow dynamics may be put into good use in their intended applications.
Download or read book Vortex Rings and the Plate Jet written by Percival D. McCormack and published by . This book was released on 1968 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transition and Mixing in Axisymmetric Jets and Vortex Rings written by Gary Arthur Allen and published by . This book was released on 1984 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transition and Mixing in Axisymmetric Jets and Vortex Rings written by Gary A. Allen and published by . This book was released on 1986 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Investigations Into Vortex Rings in Pulsed Jets written by Erdoğan Aydemir and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Vortex Rings written by D. G. Akhmetov and published by Springer Science & Business Media. This book was released on 2009-11-24 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vortex flow is one of the fundamental types of fluid and gas motion. These flows are the most spectacular in the form of concentrated vortices, characterized by the localization of vorticity (curl of velocity) in bounded regions of a space, beyond which the vorticity is either absent or rapidly falls down to zero. Concentrated vortices are often observed in nature, exemplified by atmospheric cyclones, whirlwinds and tornados, oceanic vortices, whirlpools on a water s- face, and ring vortices caused by explosive outburst of volcanoes. In technical - vices concentrated vortices form when flow separates from sharp edges of flying vehicles and ships. Among these are vortices flowing off the ends of airplane wings, and intentionally generated vortices for intensification of burning in c- bustion chambers, vortices in cyclonic devices used for mixing or separation of impurities in fluids and gases. One such remarkable and frequent type of conc- trated vortices is a vortex ring which constitutes a vortex tube closed into a t- oidal ring moving in a surrounding fluid like an isolated body out of contact with solid boundaries of the flow region if such boundaries exist. Formation and motion of vortex rings are important part of the dynamics of a continuum medium and have been studied for more than a century.
Download or read book Turbulent Coflowing Jets and Vortex Ring Collisions written by Timothy B. Nickels and published by . This book was released on 1993 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technical Report Jet Propulsion Laboratory California Institute of Technology written by Jet Propulsion Laboratory (U.S.) and published by . This book was released on 1965 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Preliminary Study of Vortex Formation from Pulsed Jets written by J. Z. Irdmusa and published by . This book was released on 1982 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is known that superior thrust augmentation may be obtained in ejectors by the use of pulsed jets as opposed to steady flow jets. Pulsed jets and other unsteady flow devices offer the advantage that they can capitalize on the reversible work of interface pressure forces as well as the usual irreversible turbulent mixing. The latter alone is employed in steady flow ejectors. When a pulsed jet discharges into a duct or an open environment, the jet forms a toroidal vortex ring which acts as a piston pushing the ambient fluid in its path. The configuration of this vortex ring can be extensively controlled by proper control of the boundary conditions at the exit of the jet. The present work is a preliminary study of the configurations of the vortex rings produced by different boundary conditions and of their subsequent behavior. It is hoped that such a study will illuminate some avenues of improvement for pulsed-jet ejector technology.
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 A Quantitative Analysis of Starting Jet Vortex Ring Entrainment at Low Reynolds Number written by Alex Geoffrey Dulude and published by . This book was released on 2007 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: The future propulsion of very small unmanned air and underwater vehicles operating at Reynolds numbers in the hundreds or less may be accomplished by pulsing a jet of fluid rather than more conventional methods of propulsion such as propellers and turbo jets as used by large-scale vehicles. Pulse jet propulsion produces trailing vortex rings and recent research concerning the formation and evolution of vortex rings has suggested that these structures may be exploited to augment the thrust and increase the efficiency of pulsed jet propulsion. Limited studies have indicated correlations between the length and shape of the generating pulse and the formation, fluid entrainment, and thrust augmentation provided by the resultant vortex ring at ring Reynolds number as low as approximately 13,000. The onset of vortex ring pinch-off has previously been shown to be a limit to this thrust augmentation. The design, construction, and implementation of a novel, piston-cylinder-type, vortex ring generator to confirm and further improve measurements of fluid entrainment and other formation characteristics has been accomplished. This apparatus was used in dye injection studies and stereoscopic particle image velocimetry (SPIV) studies to qualitatively examine the evolution of the vortex ring, and evaluate the effects of pulse length and shape on the formation of the vortex ring over a range of Reynolds numbers between 250 and 13,000. Results from this investigation at a Reynolds number of 13,000 are in close agreement with those of previous research, indicating that pulse shaping can delay the phenomena of vortex ring pinch-off by as much as 20% of the stroke length to diameter ratio. Results from lower Reynolds numbers show a trending toward even greater delay of pinch-off, as Reynolds number decreases. Tests conducted at Re=250 indicate a delay in pinch-off in excess of 400% over that seen at Re=13,000.
Download or read book An Experimental Investigation of Viscous Vortex Rings and Zero net mass flux Jets written by John Edward Cater and published by . This book was released on 2002 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Flow Control Techniques and Applications written by Jinjun Wang and published by Cambridge University Press. This book was released on 2018-12-13 with total page 293 pages. Available in PDF, EPUB and Kindle. Book excerpt: Master the theory, applications and control mechanisms of flow control techniques.
Download or read book Bifurcating and Blooming Jets written by Mario Lee and published by . This book was released on 1985 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Periodic Vortex Ring Cavity Formation in an Excited Submerged Jet written by Virgil Evans Johnson and published by . This book was released on 1987 with total page 275 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analysis of Noise Produced by an Orderly Structure of Turbulent Jets written by Jay C. Hardin and published by . This book was released on 1973 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: The orderly structure which has been observed recently by numerous researchers within the transition region of subsonic turbulent jets is analyzed to reveal its noise-producing potential. For a circular jet, this structure is molded as a train of toroidal vortex rings which are formed near the jet exit and propagate downstream. The noise produced by the model is evaluated from a reformulation of Lighthill's expression for the far-field acoustic density, which emphasizes the importance of the vorticity within the turbulent flow field. It is shown that the noise production occurs mainly close to the jet exit and depends primarily upon temporal changes in the toroidal radii. The analysis suggests that the process of formation of this regular structure may also be an important contribution of the high-frequency jet noise. These results may be helpful in the understanding of jet-noise generation and in new approaches to jet-noise suppression.
