Particle dynamics in wall-bounded thermal counterflow of superfluid helium

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F17%3A10368512" target="_blank" >RIV/00216208:11320/17:10368512 - isvavai.cz</a>

Result on the web

<a href="http://dx.doi.org/10.1063/1.4984913" target="_blank" >http://dx.doi.org/10.1063/1.4984913</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1063/1.4984913" target="_blank" >10.1063/1.4984913</a>

Result language

angličtina

Original language name

Particle dynamics in wall-bounded thermal counterflow of superfluid helium

Original language description

The motions of relatively small particles in wall-bounded thermal counterflow of superfluid helium are experimentally investigated, above 1 K, by using the particle tracking velocimetry technique. The effect of a solid boundary on this quantum flow has received little attention to date, and the focus here is on the corresponding flow-induced particle dynamics. The velocity and velocity difference statistical distributions of the particles are computed at length scales straddling two orders of magnitude across the mean distance between quantized vortices, the quantum length scale of the flow. The imposed counterflow velocity ranges between about 2 and 7 mm/s, resulting in suitably defined Reynolds numbers up to 20 000. The distributions are found to be wider in the bulk than close to the solid boundary, at small enough scales, and this suggests that the mean distance between the vortices increases with the distance from the wall. The outcome reinforces the view, supported to date solely by numerical simulations, that in thermal counterflow quantized vortices are not homogenously distributed in the channel and that they preferentially concentrate close to its walls. Boundary layers might therefore also exist in quantum flows, although some of their features appear to be significantly different from those attributed towall-bounded flows of viscous fluids, due to the presence of quantized vortices.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Project

<a href="/en/project/GA16-00580S" target="_blank" >GA16-00580S: Quantum turbulence boundaries</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2017

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Physics of Fluids

ISSN

1070-6631

e-ISSN

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Volume of the periodical

29

Issue of the periodical within the volume

6

Country of publishing house

US - UNITED STATES

Number of pages

9

Pages from-to

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UT code for WoS article

000404636900031

EID of the result in the Scopus database

2-s2.0-85020306657