Reynolds number scaling in cryogenic turbulent Rayleigh-Benard convection in a cylindrical aspect ratio one cell

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68081731%3A_____%2F17%3A00482462" target="_blank" >RIV/68081731:_____/17:00482462 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216208:11320/17:10368076

Výsledek na webu

<a href="http://dx.doi.org/10.1017/jfm.2017.638" target="_blank" >http://dx.doi.org/10.1017/jfm.2017.638</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1017/jfm.2017.638" target="_blank" >10.1017/jfm.2017.638</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Reynolds number scaling in cryogenic turbulent Rayleigh-Benard convection in a cylindrical aspect ratio one cell

Popis výsledku v původním jazyce

We perform an experimental study of turbulent Rayleigh-Benard convection up to very high Rayleigh number, 10(8) < Ra < 10(14), in a cylindrical aspect ratio one cell, 30 cm in height, filled with cryogenic helium gas. We monitor temperature fluctuations in the convective flow with four small (0.2 mm) sensors positioned in pairs 1.5 cm from the sidewalls and 2.5 cm vertically apart and symmetrically around the mid-height of the cell. Based on one-point and two-point correlations of the temperature fluctuations, we determine different types of Reynolds numbers, Re, associated with the large-scale circulation (LSC). We observe a transition between two types of Re. Ra/scaling around Ra = 10(10)-10(11), which is accompanied by a scaling change of the skewness of the probability distribution functions (PDFs) of the temperature fluctuations. The Re. Ra/dependencies measured near the sidewall at Prandtl number Pr similar to 1 are consistent with the (RaPr2/3)-Pr-4/9 scaling above the transition, while for Ra < 10(10), the Re. Ra/dependencies are steeper. It seems likely that this change in Re. Ra/scaling is linked to the previously reported change in the Nusselt number Nu. Ra/scaling. This behaviour is in agreement with independent cryogenic laboratory experiments with Pr similar to 1, but markedly different from the Re scaling obtained in water experiments (Pr similar to 3: 3-5: 6). We discuss the results in comparison with different versions of the Grossmann-Lohse theory.

Název v anglickém jazyce

Reynolds number scaling in cryogenic turbulent Rayleigh-Benard convection in a cylindrical aspect ratio one cell

Popis výsledku anglicky

We perform an experimental study of turbulent Rayleigh-Benard convection up to very high Rayleigh number, 10(8) < Ra < 10(14), in a cylindrical aspect ratio one cell, 30 cm in height, filled with cryogenic helium gas. We monitor temperature fluctuations in the convective flow with four small (0.2 mm) sensors positioned in pairs 1.5 cm from the sidewalls and 2.5 cm vertically apart and symmetrically around the mid-height of the cell. Based on one-point and two-point correlations of the temperature fluctuations, we determine different types of Reynolds numbers, Re, associated with the large-scale circulation (LSC). We observe a transition between two types of Re. Ra/scaling around Ra = 10(10)-10(11), which is accompanied by a scaling change of the skewness of the probability distribution functions (PDFs) of the temperature fluctuations. The Re. Ra/dependencies measured near the sidewall at Prandtl number Pr similar to 1 are consistent with the (RaPr2/3)-Pr-4/9 scaling above the transition, while for Ra < 10(10), the Re. Ra/dependencies are steeper. It seems likely that this change in Re. Ra/scaling is linked to the previously reported change in the Nusselt number Nu. Ra/scaling. This behaviour is in agreement with independent cryogenic laboratory experiments with Pr similar to 1, but markedly different from the Re scaling obtained in water experiments (Pr similar to 3: 3-5: 6). We discuss the results in comparison with different versions of the Grossmann-Lohse theory.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10305 - Fluids and plasma physics (including surface physics)

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

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

Rok uplatnění

2017

Kód důvěrnosti údajů

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

Název periodika

Journal of Fluid Mechanics

ISSN

0022-1120

e-ISSN

—

Svazek periodika

832

Číslo periodika v rámci svazku

OCT 26

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

24

Strana od-do

721-744

Kód UT WoS článku

000413861400001

EID výsledku v databázi Scopus

2-s2.0-85033372569