Macroscopic dynamics of the vortex tangle in He II

Journal Article · Wed Sep 01 04:00:00 EDT 1993 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.48.7338· OSTI ID:6213622

Nemirovskii, S K; Stamm, G; Fiszdon, W ^[1]

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1. Max-Planck-Institut fuer Stroemungsforschung, Bunsenstrasse 10, D-37073 Goettingen (Germany)

The problem of unsteady superfluid turbulence is considered. Vinen's phenomenological formulation of the vortex-line-density evolution equation encounters a number of difficulties. Some of them are intrinsic in the Feynman-Vinen approach, e.g., the question of an unambiguous choice of the relevant equation. Recent investigations of turbulent unsteady flows and of the vortex-tangle structure lead to new problems. In particular Schwarz suggested that the vortex-line-density evolution equation has the form of the Vinen equation but the physical mechanisms leading to it differ from those suggested by Feynman and Vinen. Reviewing the relevant problems we show that the different concepts concerning macroscopic vortex-tangle dynamics lead to differences in the hydrodynamic equations of the superfluid turbulent flows. Using this fact we devised and performed a special experiment in which a region of strongly nonequilibrium superfluid turbulence was probed by a second-sound pulse. Results of this experiment allowed us to draw two main conclusions: (i) Vinen's vortex-line-density evolution equation is valid. (ii) Schwarz's recent interpretation of the physical mechanisms leading to Vinen's equation seems to be more plausible.

• OSTI ID: 6213622
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 48:10; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

665420* -- Superfluidity-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
DIFFERENTIAL EQUATIONS
DYNAMICS
EQUATIONS
EQUATIONS OF MOTION
EVEN-EVEN NUCLEI
FLUIDS
HELIUM 4
HELIUM II
HELIUM ISOTOPES
ISOTOPES
LIGHT NUCLEI
MECHANICS
NUCLEI
PARTIAL DIFFERENTIAL EQUATIONS
QUANTUM FLUIDS
SECOND SOUND
STABLE ISOTOPES
SUPERFLUIDITY
TURBULENCE
VORTICES