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This volume contains papers arising out of the program of the Institute for Theoretical Physics (ITP) of the University of California at Santa Bar bara, August-December 1991, on the subject "Topological Fluid Dynamics". The first group of papers cover the lectures on Knot Theory, Relaxation un der Topological Constraints, Kinematics of Stretching, and Fast Dynamo Theory presented at the initial Pedagogical Workshop of the program. The remaining papers were presented at the subsequent NATO Advanced Re search Workshop or were written during the course of the program. We wish to acknowledge the support of the NATO Science Committee in making this workshop possible. The scope of "Topological Fluid Dynamics" was defined by an earlier Symposium of the International Union of Theoretical and Applied Mechan ics (IUTAM) held in Cambridge, England in August, 1989, the Proceedings of which were published (Eds. H.K. Moffatt and A. Tsinober) by Cambridge University Press in 1990. The proposal to hold an ITP program on this sub ject emerged from that Symposium, and we are grateful to John Greene and Charlie Kennel at whose encouragement the original proposal was formu lated. Topological fluid dynamics covers a range of problems, particularly those involving vortex tubes and/or magnetic flux tubes in nearly ideal fluids, for which topological structures can be identified and to some extent quantified.
Table des matières
I. Introductory Lectures.- Relaxation under Topological Constraints.- Knot Theory, Jones' Polynomials, Invariants of 3-Manifolds, and the Topological Theory of Fluid Dynamics.- Topology of Knots.- Stretching and Alignment in General Flow Fields: Classical Trajectories from Reynolds Number Zero to Infinity.- Fast Dynamo Theory.- II. Relaxation and Minimum Energy States.- Relaxation and Topology in Plasma Experiments.- Taylor's Relaxation in an Unbounded Domain of Space.- Force-Free Magnetic Fields with Constant Alpha.- Minimum Energy Magnetic Fields with Toroidal Topology.- Research Announcement on the "Energy" of Knots.- III. Helicity, Linkage, and Flow Topology.- The Helicity of a Knotted Vortex Filament.- A Heirarchy of Linking Integrals.- Borromeanism and Bordism.- Topology of Steady Fluid Flows.- IV. The Euler Equations: Extremal Properties and Finite Time Singularities.- Extremal Properties and Hamiltonian Structure of the Euler Equations.- Blow Up in Axisymmetric Euler Flows.- Is There a Finite-Time Singularity in Axisymmetric Euler Flows?.- Evidence for a Singularity of the Three-Dimensional Incompressible Euler Equations.- Singularity Formation on Vortex Sheets: The Raleigh-Taylor Problem.- V. Vortex Interactions and the Structure of Turbulence.- 2D Turbulence: New Results for Re ? ?.- On Vortex Reconnection and Turbulence.- New Aspects of Vortex Dynamics: Helical Waves, Core Dynamics, Viscous Helicity Generation, and Interaction with Turbulence.- Intermittency Growth in 3D Turbulence.- Dynamical Mechanisms for Intermittency Effects in Fully Developed Turbulence.- The Multispiral Model of Turbulence and Intermittency.- Measurements of Local Scaling of Turbulent Velocity Fields at High Reynolds Numbers.- On the Determination of Universal MultifractalParameters in Turbulence.- VI. Chaos, Instability and Dynamo Theory.- Anomolous Transport and Fractal Kinectics.- Kinematical Instability and Line-Stretching in Relation to the Geodesics of Fluid Motion.- The Behavior of Active and Passive Particles in a Chaotic Flow.- Chaos Associated with Fluid Inertia.- Instability Criteria in Fluid Dynamics.- Localized Instabilities in Fluids.- Kinematic Fast Dynamo Action in a Time-Periodic Chaotic Flow.- An Exact Turbulent Closure for the Hydromagnetic Dynamo.- Author Index.
Résumé
Proceedings of the Program of the Institute for Theoretical Physics, University of California at Santa Barbara, U.S.A. and of the NATO Advanced Research Workshop, University of California at Santa Barbara, U.S.A., November 1-5, 1991
