Comparative study of void fraction models
Creators
- 1. Instituto de Pesquisas Energeticas e Nucleares, Sao Paulo (Brazil)
Description
Some models for the calculation of void fraction in water in sub-cooled boiling and saturated vertical upward flow with forced convection have been selected and compared with experimental results in the pressure range of 1 to 150 bar. In order to know the void fraction axial distribution it is necessary to determine the net generation of vapour and the fluid temperature distribution in the slightly sub-cooled boiling region. It was verified that the net generation of vapour was well represented by the Saha-Zuber model. The selected models for the void fraction calculation present adequate results but with a tendency to super-estimate the experimental results, in particular the homogeneous models. The drift flux model is recommended, followed by the Armand and Smith models. (F.E.)
Abstract (Portuguese)
Este estudo seleciona da literatura modelos para o calculo da fracao de vazio em ebulicao subresfriada e saturada para escoamento vertical ascendente em conveccao forcada de agua. Para se conhecer a distribiuicao axial de fracao de vazio, e necessario determinar o ponto de geracao franca de vapor e a distribuicao de temperatura do fluido na regiao de ebulicao levemente subresfriada. O ponto de geracao franca de vapor e caracterizado pelo inicio marcante de formacao de vapor junto a parede do tubo aquecido mesmo com o seio do fluido ainda na condicao sub-resfriada. Por outro lado, a distribuicao de temperatura do fluido na regiao de ebulicao levemente subresfriada caracteriza a transferencia de calor sensivel e latente da parede aquecida do tubo para o fluido, ate que o mesmo atinja a temperatura de saturacao. Os resultados obtido com os modelos selecionados de fracao de vazio mostraram-se satisfatorios em relacao aos resultados experimentais, abrangendo a faixa de pressao de 1 a 150 bar. (Autor)Additional details
Additional titles
- Original title (Portuguese)
- Estudo comparativo de modelos de fracao de vazio
Publishing Information
- Imprint Title
- Proceedings of the 5. National Meeting of Reactor Physics
- Imprint Pagination
- 873 p.
- Journal Page Range
- p. 479-497.
- Report number
- INIS-BR--492
Conference
- Title
- 5. National Meeting of Reactor Physics.
- Dates
- 10-12 Apr 1985.
- Place
- Rio de Janeiro, RJ (Brazil).
INIS
- Country of Publication
- Brazil
- Country of Input or Organization
- Brazil
- INIS RN
- 17044351
- Subject category
- S42: ENGINEERING;
- Resource subtype / Literary indicator
- Conference
- Descriptors DEI
- COMPARATIVE EVALUATIONS; FLOW MODELS; STEAM GENERATORS; SUBCOOLED BOILING; VOID FRACTION; WATER
- Descriptors DEC
- BOILERS; BOILING; EVALUATION; HYDROGEN COMPOUNDS; MATHEMATICAL MODELS; OXYGEN COMPOUNDS; PHASE TRANSFORMATIONS; VAPOR GENERATORS
Optional Information
- Notes
- Imprint:Anais do 5. Encontro Nacional de Fisica de Reatores.