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Latest Developments on HeII Co-Current Two-Phase Flow Studies

Large scale experiments were performed at CEA Grenoble with the support of CERN to simulate and understand the HeII cooling circuit of the LHC. This paper describes the latest results obtained in HeII co-current two-phase flow configuration. First we summarize thermal and hydraulic behaviour of flow...

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Autores principales: Rousset, B, Gauthier, A, Grimaud, L, Van Weelderen, R
Lenguaje:eng
Publicado: 1997
Materias:
Acceso en línea:https://dx.doi.org/10.1007/978-1-4757-9047-4_180
http://cds.cern.ch/record/339987
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author Rousset, B
Gauthier, A
Grimaud, L
Van Weelderen, R
author_facet Rousset, B
Gauthier, A
Grimaud, L
Van Weelderen, R
author_sort Rousset, B
collection CERN
description Large scale experiments were performed at CEA Grenoble with the support of CERN to simulate and understand the HeII cooling circuit of the LHC. This paper describes the latest results obtained in HeII co-current two-phase flow configuration. First we summarize thermal and hydraulic behaviour of flows obtained in a 40 mm I.D., 86 m long tube inclined at 1.4% which resembles closely the LHC heat exchanger tube. For low vapour velocities, the flow pattern is found to be stratified. A model based on this observation has been developed which fits very well the measured pressure losses. However the wetted surface predicted by the model underestimates the measured one, notably for high vapour velocities. In that case, liquid droplets entrainment takes place. Droplets landing on the tube wall increase the wetted surface. Thus we infer that for higher vapour velocities, the stratified two-phase flow model should not be applied anymore. In order to validate the range of availability of the model, and begin to draw a flow pattern map, a 20 mm I.D. horizontal test sector was built and experiments were performed. First results are presented here, including the observation of the stratified-annular flow transition.
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institution Organización Europea para la Investigación Nuclear
language eng
publishDate 1997
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spelling cern-3399872023-05-31T13:19:58Zdoi:10.1007/978-1-4757-9047-4_180http://cds.cern.ch/record/339987engRousset, BGauthier, AGrimaud, LVan Weelderen, RLatest Developments on HeII Co-Current Two-Phase Flow StudiesAccelerators and Storage RingsLarge scale experiments were performed at CEA Grenoble with the support of CERN to simulate and understand the HeII cooling circuit of the LHC. This paper describes the latest results obtained in HeII co-current two-phase flow configuration. First we summarize thermal and hydraulic behaviour of flows obtained in a 40 mm I.D., 86 m long tube inclined at 1.4% which resembles closely the LHC heat exchanger tube. For low vapour velocities, the flow pattern is found to be stratified. A model based on this observation has been developed which fits very well the measured pressure losses. However the wetted surface predicted by the model underestimates the measured one, notably for high vapour velocities. In that case, liquid droplets entrainment takes place. Droplets landing on the tube wall increase the wetted surface. Thus we infer that for higher vapour velocities, the stratified two-phase flow model should not be applied anymore. In order to validate the range of availability of the model, and begin to draw a flow pattern map, a 20 mm I.D. horizontal test sector was built and experiments were performed. First results are presented here, including the observation of the stratified-annular flow transition.LHC-Project-Report-150CERN-LHC-Project-Report-150oai:cds.cern.ch:3399871997-11-04
spellingShingle Accelerators and Storage Rings
Rousset, B
Gauthier, A
Grimaud, L
Van Weelderen, R
Latest Developments on HeII Co-Current Two-Phase Flow Studies
title Latest Developments on HeII Co-Current Two-Phase Flow Studies
title_full Latest Developments on HeII Co-Current Two-Phase Flow Studies
title_fullStr Latest Developments on HeII Co-Current Two-Phase Flow Studies
title_full_unstemmed Latest Developments on HeII Co-Current Two-Phase Flow Studies
title_short Latest Developments on HeII Co-Current Two-Phase Flow Studies
title_sort latest developments on heii co-current two-phase flow studies
topic Accelerators and Storage Rings
url https://dx.doi.org/10.1007/978-1-4757-9047-4_180
http://cds.cern.ch/record/339987
work_keys_str_mv AT roussetb latestdevelopmentsonheiicocurrenttwophaseflowstudies
AT gauthiera latestdevelopmentsonheiicocurrenttwophaseflowstudies
AT grimaudl latestdevelopmentsonheiicocurrenttwophaseflowstudies
AT vanweelderenr latestdevelopmentsonheiicocurrenttwophaseflowstudies