Download or read book On a Criterion for Vortex Breakdown written by R. E. Spall and published by . This book was released on 1987 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Simple Criterion for Vortex Breakdown written by K. Ravindra and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Simple Criterion for Vortex Breakdown written by E. J. Jumper and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Simple Numerical Criterion for Vortex Breakdown written by B. A. Robinson and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Initiation and Criterion of Axisymmetric Vortex Breakdown written by Wei Wu and published by . This book was released on 1995 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Examination of a Group velocity Criterion for the Breakdown of an Idealized Vortex Flow written by and published by . This book was released on 1979 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Group velocity Criterion for Breakdown of Vortex Flow An Application to Measured Inlet Profiles written by and published by . This book was released on 1979 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Towards a Universal Criterion for Predicting Vortex Breakdown in Swirling Jets written by Aran Fitzgerald and published by . This book was released on 2006 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Bubble Concept of Axisymmetric Vortex Breakdown with and Without Obstacles in the Vortex Core written by Hans J. Lugt and published by . This book was released on 1988 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is now sufficient evidence that axisymmetric recirculation zones in the form of 'bubbles' on the axis of rotation of a vortex can be steady-state and stable. It appears also that the majority of researchers accept these bubbles as a form or a part of vortex breakdown. However, a gray area with regard to the definition of vortex breakdown exists when no stagnation point at the axis of rotation occurs. To use the appearance of such a stagnation point as a criterion for vortex breakdown might be too restrictive. The situation becomes even more aggravated when an obstacle is placed on the axis of rotation. Are recirculation (or separation) regions in the front and rear of the obstacle indications of vortex breakdown or of Taylor-Proudman columns? This report addresses some of the problems in context with vortex control. Keyword: Vortex control. (edc).

Download or read book Computational Studies of Vortex Breakdown written by and published by . This book was released on 1992 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: Axisymmetric vortex breakdown was simulated numerically within an enclosed circular cylinder with: (1) fixed cylindrical wall-endwall and one rotating lid; and (2) rotating cylindrical wall-endwall with a differentially rotating lid. Variations of the two dynamical parameters permitted the calculation of cases in which incipient vortex breakdown was observed. A vortex breakdown criterion recently proposed by Brown & Lopez was tested against these numerical solutions.

Download or read book On Vortex Breakdown and Instability written by S. N. Singh and published by . This book was released on 1981 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: A literature survey on the vortex breakdown phenomenon is presented. Several theoretical and numerical models which have been proposed and applied to explain the experimental observations concerning vortex bursting are reviewed. Required parameters to perform the related stability analysis have been identified. Appropriate criteria where possible are cited to assist engineers in estimating occurrence of vortext bursting. A numerical scheme to compute and verify some of the results for incompressible inviscid unstable modes is programmed on the computer at WPAFB. It is suggested that the influence of adverse pressure gradient on the vortex breakdown be investigated in detail and results thus obtained be compared with experiments under appropriate conditions.

Download or read book Liutex and Its Applications in Turbulence Research written by Chaoqun Liu and published by Academic Press. This book was released on 2020-10-29 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt: Liutex and Its Applications in Turbulence Research reviews the history of vortex definition, provides an accurate mathematical definition of vortices, and explains their applications in flow transition, turbulent flow, flow control, and turbulent flow experiments. The book explains the term "Rortex" as a mathematically defined rigid rotation of fluids or vortex, which could help solve many longstanding problems in turbulence research. The accurate mathematical definition of the vortex is important in a range of industrial contexts, including aerospace, turbine machinery, combustion, and electronic cooling systems, so there are many areas of research that can benefit from the innovations described here. This book provides a thorough survey of the latest research in generalized and flow-thermal, unified, law-of-the-wall for wall-bounded turbulence. Important theory and methodologies used for developing these laws are described in detail, including: the classification of the conventional turbulent boundary layer concept based on proper velocity scaling; the methodology for identification of the scales of velocity, temperature, and length needed to establish the law; and the discovery, proof, and strict validations of the laws, with both Reynolds and Prandtl number independency properties using DNS data. The establishment of these statistical laws is important to modern fluid mechanics and heat transfer research, and greatly expands our understanding of wall-bounded turbulence. Provides an accurate mathematical definition of vortices Provides a thorough survey of the latest research in generalized and flow-thermal, unified, law-of-the-wall for wall-bounded turbulence Explains the term “Rortex as a mathematically defined rigid rotation of fluids or vortex Covers the statistical laws important to modern fluid mechanics and heat transfer research, and greatly expands our understanding of wall-bounded turbulence

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 Vortex Breakdown Incipience Theoretical Considerations written by S. A. Berger and published by . This book was released on 1992 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: The sensitivity of the onset and the location of vortex breakdowns in concentrated vortex cores, and the pronounced tendency of the breakdowns to migrate upstream have been characteristic observations of experimental investigations; they have also been features of numerical simulations and led to questions about the validity of these simulations. This behavior seems to be inconsistent with the strong time-like axial evolution of the flow, as expressed explicitly, for example, by the quasi-cylindrical approximate equations for this flow. An order-of-magnitude analysis of the equations of motion near breakdown leads to a modified set of governing equations, analysis of which demonstrates that the interplay between radial inertial, pressure, and viscous forces gives an elliptic character to these concentrated swirling flows. Analytical, asymptotic, and numerical solutions of a simplified non-linear equation are presented; these qualitatively exhibit the features of vortex onset and location noted above.

Download or read book Vortex Dominated Flows written by Lu Ting and published by World Scientific. This book was released on 2005 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: Honoring the contributions of one of the field''s leading experts, Lu Ting, this indispensable volume contains important new results at the cutting edge of research. A wide variety of significant new analytical and numerical results in critical areas are presented, including point vortex dynamics, superconductor vortices, cavity flows, vortex breakdown, shock/vortex interaction, wake flows, magneto-hydrodynamics, rotary wake flows, and hypersonic vortex phenomena. The book will be invaluable for those interested in the state of the art of vortex dominated flows, both from a theoretical and applied perspective. Professor Lu Ting and Joe Keller have worked together for over 40 years. In their first joint work entitled OC Periodic vibrations of systems governed by nonlinear partial differential equationsOCO, perturbation analysis and bifurcation theory were used to determine the frequencies and modes of vibration of various physical systems. The novelty was the application to partial differential equations of methods which, previously, had been used almost exclusively on ordinary differential equations. Professsor Lu Ting is an expert in both fluid dynamics and the use of matched asymptotic expansions. His physical insight into fluid flows has led the way to finding the appropriate mathematical simplications used in the solutions to many difficult flow problems."

Download or read book Vortex Stability and Breakdown written by S. Leibovich and published by . This book was released on 1983 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: Theoretical and experimental results, some quite recent, on the instability and breakdown of concentrated vortices at high Reynolds numbers are reviewed. Wave related theories of the vortex breakdown phenomena are treated in some detail; these appear to provide a qualitative description of the response of vortex breakdown to variations in swirl or flow rate, and Benjamin's criticality classification, a wave-based concept, is consistent with experimental data. Known general criteria for the stability of instability of inviscid columnar vortices are reviewed, together with numerical studies of an inviscid vortex model that provides an excellent analytical fit to measured velocity profiles in vortices that experience breakdown. A new analysis of experimental data on vortex breakdown flows sheds light on the interplay between criticality and instability. The flows sufficiently far upstream of breakdowns to be unaffected by them are supercritical and stable, but they are generally closer to marginal instability than they are to criticality. The wakes are both subcritical and unstable. A conceptual framework for vortex breakdown, incorporating nonlinear wave theory and instability to three-dimensional disturbances, is suggested based on information derived from the experimental studies. (Author).

Download or read book Disrupted States of Vortex Flow and Vortex Breakdown written by James Henry Faler and published by . This book was released on 1977 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: