Název: Experimental study of high rayleigh number convection using cryogenic gaseous 4He
Autoři: Urban, Pavel ; Musilová, Věra ; Skrbek, L.
Typ dokumentu: Příspěvky z konference
Konference/Akce: Experimental Fluid Mechanics 2010 -EFM10, Liberec (CZ), 2010-11-24 / 2010-11-26
Rok: 2010
Jazyk: eng
Abstrakt: Several laboratories worldwide try to elucidate the underlying mechanisms of turbulent thermal convection using cryogenic He gas, a working fluid with truly remarkable and widely tuneable properties. The focus is on the efficiency of the heat transfer, experimentally studied via the Nusselt (Nu) versus Rayleigh number (Ra) dependence, especially at very high Ra. In order to resolve existing controversies among published results, we designed and built a cryogenic apparatus capable of reaching Ra up to 2 × 10e15, thus covering the range of interest where various transitions such as that into the theoretically predicted ultimate Kraichnan regime have been claimed. The cylindrical convection cell of 300 mm both in diameter and height is designed to withstand pressures up to 250 kPa at working temperatures between 4.2 K and 12 K. The main advantage of this apparatus is minimized influence of its cell design and materials used on the studied convection. The first experimental results are resented.
Klíčová slova: convection; Kraichnan regime; Rayleigh number; turbulent thermal convection
Číslo projektu: CEZ:AV0Z20650511 (CEP), KJB200650902 (CEP), GA202/05/0218 (CEP), ED0017/01/01
Poskytovatel projektu: GA AV ČR, GA ČR, GA MŠk
Zdrojový dokument: Proceedings of the International Conference Experimental Fluid Mechanics 2010, ISBN 978-80-7372-670-6

Instituce: Ústav přístrojové techniky AV ČR (web)
Informace o dostupnosti dokumentu: Dokument je dostupný v příslušném ústavu Akademie věd ČR.
Původní záznam: http://hdl.handle.net/11104/0191844

Trvalý odkaz NUŠL: http://www.nusl.cz/ntk/nusl-42197


Záznam je zařazen do těchto sbírek:
Věda a výzkum > AV ČR > Ústav přístrojové techniky
Konferenční materiály > Příspěvky z konference