Second-sound studies of coflow and counterflow of superfluid 4He in channels

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378271%3A_____%2F15%3A00455207" target="_blank" >RIV/68378271:_____/15:00455207 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1063/1.4921816" target="_blank" >http://dx.doi.org/10.1063/1.4921816</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1063/1.4921816" target="_blank" >10.1063/1.4921816</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Second-sound studies of coflow and counterflow of superfluid 4He in channels

Popis výsledku v původním jazyce

We report a comprehensive study of turbulent superfluid 4He flow through a channel of square cross section. We study for the first time two distinct flow configurations with the same apparatus: coflow (normal and superfluid components move in the same direction), and counterflow (normal and superfluid components move in opposite directions). We realise also a variation of counterflow with the same relative velocity, but where the superfluid component moves while there is no net flow of the normal component through the channel, i.e., pure superflow . We use the second-sound attenuation technique to measure the density of quantised vortex lines in the temperature range 1.2 K T T? 2.18 K and for flow velocities from about 1 mm/s up to almost 1 m/s in fully developed turbulence. We find that both the steady-state and temporal decay of the turbulence significantly differ in the three flow configurations, yielding an interesting insight into two-fluid hydrodynamics.

Název v anglickém jazyce

Second-sound studies of coflow and counterflow of superfluid 4He in channels

Popis výsledku anglicky

We report a comprehensive study of turbulent superfluid 4He flow through a channel of square cross section. We study for the first time two distinct flow configurations with the same apparatus: coflow (normal and superfluid components move in the same direction), and counterflow (normal and superfluid components move in opposite directions). We realise also a variation of counterflow with the same relative velocity, but where the superfluid component moves while there is no net flow of the normal component through the channel, i.e., pure superflow . We use the second-sound attenuation technique to measure the density of quantised vortex lines in the temperature range 1.2 K T T? 2.18 K and for flow velocities from about 1 mm/s up to almost 1 m/s in fully developed turbulence. We find that both the steady-state and temporal decay of the turbulence significantly differ in the three flow configurations, yielding an interesting insight into two-fluid hydrodynamics.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

BM - Fyzika pevných látek a magnetismus

OECD FORD obor

—

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2015

Kód důvěrnosti údajů

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

Název periodika

Physics of Fluids

ISSN

1070-6631

e-ISSN

—

Svazek periodika

27

Číslo periodika v rámci svazku

6

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

22

Strana od-do

"065101-1"-"065101-22"

Kód UT WoS článku

000357688800038

EID výsledku v databázi Scopus

2-s2.0-84930960256