Interactions between normal-fluid and superfluid vortex rings in helium-4

Kivotides, Demosthenes (2015) Interactions between normal-fluid and superfluid vortex rings in helium-4. EPL: A Letters Journal Exploring the Frontiers of Physics, 112 (3). 36005. ISSN 0295-5075 (https://doi.org/10.1209/0295-5075/112/36005)

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Abstract

By employing both vortex-dynamical and self-consistent Navier-Stokes methods of analysis, an investigation of interactions between normal-fluid and superfluid vortex rings in helium-4 is performed. It is shown that, under the influence of normal-fluid vortices, superfluid vortices grow in size in order to match the size of the latter. In turbulence, this mechanism hints to a tendency towards scale-to-scale energy equipartition in the spectral regimes corresponding to the inertial-range in the normal-fluid. Yet, the analysis shows that the induced superfluid vorticity is not trapped by the cores of the normal-fluid vortices, and, consequently, there is no strong correlation between normal-fluid and induced superfluid vorticity patterns. Hence, there is no significant vortex locking effect.