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ISSN Online: 2377-424X

ISBN Print: 0-89116-559-2

International Heat Transfer Conference 8
August, 17-22, 1986, San Francisco, USA

FILM BOILING DESTABILISATION

Get access (open in a dialog) DOI: 10.1615/IHTC8.3990
pages 2037-2042

Аннотация

Film boiling was established around a pre-heated solid brass rod immersed in a static pool of water and both untriggered and triggered film boiling collapse were investigated. The effects of varying metal temperature (up to 500°C) and subcooling (0 to 80 ° C) were studied and collapse was initiated by pressure pulses typical of MFCI triggers. A steady state model of laminar film boiling has been developed and is used to interpret the experimental results. The minimum film boiling temperature was determined as a function of subcooling and is shown to depend on surface roughness and interface instabilities. A threshold for triggered film boiling collapse with a particular pressure pulse was established over a range of subcoolings. Such information has previously not been available and this result is used to validate a simple criterion for triggered film boiling collapse. Film boiling was observed to re-establish when collapse was triggered above a 'thermal threshold'. Pressure pulses were generated during collapse and may be relevant to the initial fragmentation of an MFCI.