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Lookup NU author(s): Dr George Stagg, Professor Nick ParkerORCiD, Professor Carlo Barenghi
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
We model the superfluid flow of liquid helium over the rough surface of a wire (used to experimentally generate turbulence) profiled by atomic force microscopy. Numerical simulations of the Gross-Pitaevskii equation reveal that the sharpest features in the surface induce vortex nucleation both intrinsically (due to the raised local fluid velocity) and extrinsically (providing pinning sites to vortex lines aligned with the flow). Vortex interactions and reconnections contribute to form a dense turbulent layer of vortices with a nonclassical average velocity profile which continually sheds small vortex rings into the bulk. We characterize this layer for various imposed flows. As boundary layers conventionally arise from viscous forces, this result opens up new insight into the nature of superflows.
Author(s): Stagg GW, Parker NG, Barenghi CF
Publication type: Article
Publication status: Published
Journal: Physical Review Letters
Year: 2017
Volume: 118
Print publication date: 31/03/2017
Online publication date: 28/03/2017
Acceptance date: 18/03/2017
Date deposited: 31/03/2017
ISSN (print): 0031-9007
ISSN (electronic): 1079-7114
Publisher: American Physical Society
URL: https://doi.org/10.1103/PhysRevLett.118.135301
DOI: 10.1103/PhysRevLett.118.135301
Data Access Statement: http://dx.doi.org/10.17634/101785-5
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