Download or read book Nonlinear Interaction Between Spiral and Axisymmetrical Disturbances in Vortex Breakdown written by Jei-hsuan Huang and published by . This book was released on 1974 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Onset of Non axisymmetric Vortex Breakdown written by Andrew W. Cary and published by . This book was released on 1997 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Introduction to Vortex Dynamics written by and published by . This book was released on 1986 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Axisymmetric and Non Axisymmetric Initiation of Vortex Breakdown written by and published by . This book was released on 2003 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Investigation of Three dimensional Vortex Breakdown written by Keith Vincent Lucas and published by . This book was released on 1997 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1973 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Theory of Concentrated Vortices written by S. V. Alekseenko and published by Springer Science & Business Media. This book was released on 2007-08-29 with total page 505 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents comprehensive and authoritative coverage of the wide field of concentrated vortices observed in nature and technique. The methods for research of their kinematics and dynamics are considered. Special attention is paid to the flows with helical symmetry. The authors have described models of vortex structures used for interpretation of experimental data which serve as a ground for development of theoretical and numerical approaches to vortex investigation.
Download or read book Crossflow Vortex Breakdown on Swept Wings written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: The spatial evolution of cross flow-vortex packets in a laminar boundary layer on a swept wing are computed by the direct numerical simulation of the incompressible Navier- Stokes equations. A wall-normal velocity distribution of steady suction and blowing at the wing surface is used to generate a strip of equally spaced and periodic disturbances along the span. Three simulations are conducted to study the effect of initial amplitude on the disturbance evolution, to determine the role of traveling cross ow modes in transition, and to devise a correlation function to guide theories of transition prediction. In each simulation, the vortex packets first enter a chordwise region of linear independent growth, then, the individual packets coalesce downstream and interact with adjacent packets, and, finally, the vortex packets nonlinearly interact to generate inflectional velocity profiles. As the initial amplitude of the disturbance is increased, the length of the evolution to breakdown decreases. For this pressure gradient, stationary modes dominate the disturbance evolution. A two-coeffcient function was devised to correlate the simulation results. The coefficients, combined with a single simulation result, provide sufficient information to generate the evolution pattern for disturbances of any initial amplitude. Joslin, R. D. and Streett, C. L. Langley Research Center ...
Download or read book Numerical Simulation of Vortex Breakdown by the Vortex filament Method written by Y. Nakamura and published by . This book was released on 1983 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: The vortex-filament method was applied to the simulation of vortex breakdown. The principal vortex region was represented by multiple filaments, and an axial velocity component was induced by a spiral winding of the filaments. First, an accuracy check was performed for a cylindrical swirling flow field that can be simulated to any accuracy by increasing the number of filaments. Second, an axisymmetric-type vortex breakdown was simulated, with experimental data serving asupstream conditions. The calculated axial- and theta-velocity contours show the breakdown of the vortex, including a rapid change in the vortex core, followed axially by a recovery zone and then a second breakdown. When three-dimensional initial data are used the second breakdown appears to be out of the spiral type in correspondence with experimental observations. The present method can easily be used to simulate other types of vortex breakdown or other vortex flows with axial velocity.
Download or read book American Doctoral Dissertations written by and published by . This book was released on 1973 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies of Vortex Dominated Flows written by M.Y. Hussaini and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 367 pages. Available in PDF, EPUB and Kindle. Book excerpt: From the astrophysical scale of a swirling spiral galaxy, through the geophysical scale of a hurricane, down to the subatomic scale of elementary particles, vortical motion and vortex dynamics have played a profound role in our understanding of the physical world. Kuchemann referred to vortex dynamics as "the sinews and muscles of fluid motion. " In order to update our understanding of vortex dominated flows, NASA Langley Research Center and the Institute for Computer Applications in Science and Engineering (ICASE) conducted a workshop during July 9-11, 1985. The subject was broadly divided into five overlapping topics vortex dynamics, vortex breakdown, massive separation, vortex shedding from sharp leading edges and conically separated flows. Some of the experts in each of these areas were invited to provide an overview of the subject. This volume is the proceedings of the workshop and contains the latest, theoretical, numerical, and experimental work in the above-mentioned areas. Leibovich, Widnall, Moore and Sirovich discussed topics on the fundamentals of vortex dynamics, while Keller and Hafez treated the problem of vortex break down phenomena; the contributions of Smith, Davis and LeBalleur were in the area of massive separation and inviscid-viscous interactions, while those of Cheng, Hoeijmakers and Munnan dealt with sharp-leading-edge vortex flows; and Fiddes and Marconi represented the category of conical separated flows.
Download or read book Interaction of a Shock with a Longitudinal Vortex written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-05 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this paper we study the shock/longitudinal vortex interaction problem in axisymmetric geometry. Linearized analysis for small vortex strength is performed, and compared with results from a high order axisymmetric shock-fitted Euler solution obtained for this purpose. It is confirmed that for weak vortices, predictions from linear theory agree well with results from nonlinear numerical simulations at the shock location. To handle very strong longitudinal vortices, which may ultimately break the shock, we use an axisymmetric high order essentially non-oscillatory (ENO) shock capturing scheme. Comparison of shock-captured and shock-fitted results are performed in their regions of common validity. We also study the vortex breakdown as a function of Mach number ranging from 1.3 to 10, thus extending the range of existing results. For vortex strengths above a critical value. a triple point forms on the shock and a secondary shock forms to provide the necessary deceleration so that the fluid velocity can adjust to downstream conditions at the shock. Erlebacher, Gordon and Hussaini, M. Y. and Shu, Chi-Wang Langley Research Center NAS 1-19480; NSF DMS-95-00814; AF-AFSOR-95-1-0074; DAAH-04-94-G-0205; NAG 1-1145; RTOP 505-90-52-01...
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 IUTAM Symposium on Nonlinear Instability and Transition in Three Dimensional Boundary Layers written by Peter W. Duck and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most fluid flows of practical importance are fully three-dimensional, so the non-linear instability properties of three-dimensional flows are of particular interest. In some cases the three-dimensionality may have been caused by a finite amplitude disturbance whilst, more usually, the unperturbed state is three-dimensional. Practical applications where transition is thought to be associated with non-linearity in a three- dimensional flow arise, for example, in aerodynamics (swept wings, engine nacelles, etc.), turbines and aortic blood flow. Here inviscid `cross-flow' disturbances as well as Tollmien-Schlichting and Görtler vortices can all occur simultaneously and their mutual non-linear behaviour must be understood if transition is to be predicted. The non-linear interactions are so complex that usually fully numerical or combined asymptotic/numerical methods must be used. Moreover, in view of the complexity of the instability processes, there is also a growing need for detailed and accurate experimental information. Carefully conducted tests allow us to identify those elements of a particular problem which are dominant. This assists in both the formulation of a relevant theoretical problem and the subsequent physical validation of predictions. It should be noted that the demands made upon the skills of the experimentalist are high and that the tests can be extremely sophisticated - often making use of the latest developments in flow diagnostic techniques, automated high speed data gathering, data analysis, fast processing and presentation.
Download or read book Paper written by and published by . This book was released on 1989 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Study of Turbulent Swirling Flows written by Bach Thien Vu and published by . This book was released on 1983 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt:
