Download or read book On the Stability of Vortex Motions in the Presence of Magnetic Fields written by Y. T. Fung and published by . This book was released on 1982 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stability analyses are performed on a general type of vortex flows with density inhomogeneity and with both the axial and azimuthal magnetic fields. A sufficient condition for stability, subject to arbitrary perturbations, is derived. The condition, however, involves the complex eigenfrequency. Nevertheless, we are able to examine how the flow profile influences the flow characteristics by studying three general types of perturbations. Analytical solutions are obtained to support the resultant arguments. Unlike the axial velocity which always destabilizes the flow, the azimuthal velocity can convey either stabilizing or destabilizing effects depending on the gradient it possesses and the centrifugal force field it creates. This characteristic is shown in all the three general types of perturbations to the flow. For flow subject to azimuthal perturbations, an upper bound on the complex phase velocity, which is reminiscent of the semi-ellipse theorem in the non-hydromagnetic case, is found for some flow profiles satisfying a constraint. Even though it cannot be observed directly from the sufficiency conditions or from the bound on the unstable waves, we are able to show that the presence of the magnetic field, regardless of the detailed profile, always stabilizes azimuthal perturbations. Such an argument is also supported by exact solutions to the governing stability equations. For uniform rotation and constant Alfven velocities, azimuthal instabilities can only occur when negative density gradients exist within the flow domain. Furthermore, the phase velocity for such instabilities must lie on a semi-circle in the complex phase velocity plane independent of the detailed density profile.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1983 with total page 756 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1973 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Vortex Processes and Solid Body Dynamics written by B. Rabinovich and published by Springer. This book was released on 1994-10-31 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents an original treatment of the influence of different types of vortex fields on the dynamics of solid bodies. This is encountered in many ways: flight dynamics, hydrofoil vehicle dynamics, rockets and spacecraft dynamics, and satellite dynamics. The volume investigates not only dissipative effects, but also the effect of liquid vortex motion kinetic energy. The dynamics of objects for which vortex fields may play a dominant role is described based on a common phenomenological model of unsteady eddy currents and vortex motion of liquids. Translated from the Russian. Annotation copyright by Book News, Inc., Portland, OR
Download or read book On the Stability of Vortex Motions in Compressible Stratified Fluids written by Y. T. Fung and published by . This book was released on 1981 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Necessary conditions for stability of a general class of compressible vortex flows are obtained using the method of generalized progressing wave expansion. The vortex motion and its density are assumed to vary in both the radial and axial directions. These conditions, representing a state of statically stable distribution for the steady flow, require that the flow be stable in the centrifugal force field created by the rotation of the fluids, in the gravitational force field arised from the density variation in the vertical direction, and in the pressure field constraining the density stratification in both directions. These results also suggest the likely behavior of the Richardson criterion for stability of the flow yet to be derived. (Author).
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 The Vortex State written by N. Bontemps and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the most spectacular consequences of the description of the superfluid condensate in superfluid He or in superconductors as a single macroscopic quantum state is the quantization of circulation, resulting in quantized vortex lines. This book draws no distinction between superfluid He3 and He4 and superconductors. The reader will find the essential introductory chapters and the most recent theoretical and experimental progress in our understanding of the vortex state in both superconductors and superfluids, from lectures given by leading experts in the field, both experimentalists and theoreticians, who gathered in Cargèse for a NATO ASI. The peculiar features related to short coherence lengths, 2D geometry, high temperatures, disorder, and pinning are thoroughly discussed.
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1976 with total page 964 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book OAR Cumulative Index of Research Results written by and published by . This book was released on 1967 with total page 1264 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Indian Science Abstracts written by and published by . This book was released on 1972 with total page 1024 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Astronomy and Astrophysics Abstracts written by S. Böhme and published by Springer Science & Business Media. This book was released on 2013-12-14 with total page 1180 pages. Available in PDF, EPUB and Kindle. Book excerpt: From the reviews: Astronomy and Astrophysics Abstracts has appeared in semi-annual volumes since 1969 and it has already become one of the fundamental publications in the fields of astronomy, astrophysics and neighbouring sciences. It is the most important English-language abstracting journal in the mentioned branches. ... The abstracts are classified under more than hundred subject categories, thus permitting a quick survey of the whole extended material. The AAA is a valuable and important publication for all students and scientists working in the fields of astronomy and related sciences. As such it represents a necessary ingredient of any astronomical library all over the world." Space Science Reviews #1 "Dividing the whole field plus related subjects into 108 categories, each work is numbered and most are accompanied by brief abstracts. Fairly comprehensive cross-referencing links relevant papers to more than one category, and exhaustive author and subject indices are to be found at the back, making the catalogues easy to use. The series appears to be so complete in its coverage and always less than a year out of date that I shall certainly have to make a little more space on those shelves for future volumes." The Observatory Magazine #1
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1964 with total page 1528 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Plasma Physics Index written by and published by . This book was released on 1982 with total page 936 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Superconductivity written by Philippe Mangin and published by Springer. This book was released on 2016-12-20 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book proposes a thorough introduction for a varied audience. The reader will master London theory and the Pippard equations, and go on to understand type I and type II superconductors (their thermodynamics, magnetic properties, vortex dynamics, current transport...), Cooper pairs and the results of BCS theory. By studying coherence and flux quantization he or she will be lead to the Josephson effect which, with the SQUID, is a good example of the applications. The reader can make up for any gaps in his knowledge with the use of the appendices, follow the logic behind each model, and assimilate completely the underlying concepts. Approximately 250 illustrations help in developing a thorough understanding. This volume is aimed towards masters and doctoral students, as well as advanced undergraduates, teachers and researchers at all levels coming from a broad range of subjects (chemistry, physics, mechanical and electrical engineering, materials science...). Engineers working in industry will have a useful introduction to other more applied or specialized material. Philippe Mangin is emeritus professor of physics at Mines Nancy Graduate School of Science, Engineering and Management of the University of Lorraine, and researcher at the Jean Lamour Institute in France. He is the former director of both the French neutron scattering facility, Léon Brillouin Laboratory in Orsay, and the Material Physics Laboratory in Nancy, and has taught superconductivity to a broad audience, in particular to engineering students. Rémi Kahn is a retired senior research scientist of the French Alternative Energies and Atomic Energy Commission (CEA-Saclay). He worked at the Léon Brillouin Laboratory and was in charge of the experimental areas of INB 101 (the Orphée research reactor). This work responded to the need to bring an accessible account suitable for a wide spectrum of scientists and engineers.
Download or read book Journal of Technical Physics written by and published by . This book was released on 1999 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the National Institute of Sciences of India written by National Institute of Sciences of India and published by . This book was released on 1961 with total page 738 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Stability of a Vortex Pair in the Presence of a Ground Plane written by Nicholas R. Rotta and published by . This book was released on 1971 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: The configuration stability of a vortex pair in the presence of a ground plane is examined. First the motion of a vortex in three dimensions is examined by the method of matched asymptotic expansions in which the solution of the Navier-Stokes equations are constructed asymptotically. The dependence of the velocity and stability of the vortex on factors such as the outer(inviscid) flow field and viscosity in the inner (vortical core) region is clearly established. The proximity of the ground plane enters through the outer solution which is matched to the inner, viscosity dependent, solution. The vortex pair in ground effect is shown to be unstable to disturbances of all wavelengths with increasing amplification rate as the ground is approached. Indications are that the present analysis predicts a more stable (less unstable) vortex system than does the inviscid theory. Comparison of the present analysis, in the limit of zero ground effect, with photographs of vortices undergoing a configuration instability is made. The viscosity necessary for agreement is found to be on the order of the eddy viscosity for the turbulent line vortex, indicating the existence of turbulence in the vortex core. (Author).
