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Original title:
Experimental study of high rayleigh number convection using cryogenic gaseous 4He
Authors: Urban, Pavel ; Musilová, Věra ; Skrbek, L.
Document type: Papers
Conference/Event: Experimental Fluid Mechanics 2010 -EFM10, Liberec (CZ), 2010-11-24 / 2010-11-26
Year: 2010
Language: eng
Abstract: 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.
Keywords: convection; Kraichnan regime; Rayleigh number; turbulent thermal convection
Project no.: CEZ:AV0Z20650511 (CEP), KJB200650902 (CEP), GA202/05/0218 (CEP), ED0017/01/01
Funding provider: GA AV ČR, GA ČR, GA MŠk
Host item entry: Proceedings of the International Conference Experimental Fluid Mechanics 2010, ISBN 978-80-7372-670-6
Institution: Institute of Scientific Instruments AS ČR (web)
Document availability information: Fulltext is available at the institute of the Academy of Sciences.
Original record: http://hdl.handle.net/11104/0191844
Permalink: http://www.nusl.cz/ntk/nusl-42197
The record appears in these collections:
Research > Institutes ASCR > Institute of Scientific Instruments
Conference materials > Papers
Authors: Urban, Pavel ; Musilová, Věra ; Skrbek, L.
Document type: Papers
Conference/Event: Experimental Fluid Mechanics 2010 -EFM10, Liberec (CZ), 2010-11-24 / 2010-11-26
Year: 2010
Language: eng
Abstract: 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.
Keywords: convection; Kraichnan regime; Rayleigh number; turbulent thermal convection
Project no.: CEZ:AV0Z20650511 (CEP), KJB200650902 (CEP), GA202/05/0218 (CEP), ED0017/01/01
Funding provider: GA AV ČR, GA ČR, GA MŠk
Host item entry: Proceedings of the International Conference Experimental Fluid Mechanics 2010, ISBN 978-80-7372-670-6
Institution: Institute of Scientific Instruments AS ČR (web)
Document availability information: Fulltext is available at the institute of the Academy of Sciences.
Original record: http://hdl.handle.net/11104/0191844
Permalink: http://www.nusl.cz/ntk/nusl-42197
The record appears in these collections:
Research > Institutes ASCR > Institute of Scientific Instruments
Conference materials > Papers
Record created 2011-07-04, last modified 2024-01-26