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A new approach in the modeling of the critical heat flux and enhancement techniques
Author(s) -
Sefiane Khellil
Publication year - 2001
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690471104
Subject(s) - boiling , meniscus , instability , mechanics , evaporation , critical heat flux , flux (metallurgy) , heat flux , field (mathematics) , materials science , thermodynamics , heat transfer , physics , optics , metallurgy , mathematics , incidence (geometry) , pure mathematics
Abstract Understanding of the boiling crisis mechanism is still incomplete; starting from experimental observations of the dry spots during boiling crisis, a new approach to bridge this gap is proposed. The thermal instabilities occurring at the triple contact lines where evaporation is intense are focused on. The “dry‐out” phenomenon is local; it depends on the local conditions at a very tiny evaporating meniscus adjacent to the heating surface. The enhancing role of EHD for CHF is studied through a stability analysis of the meniscus subjected to an electrical‐field. The equations describing the evaporating system are modified to account for the effect of electrical forces. We have found that the electrical‐field delays thermocapillary instability. Our analysis revealed that the onset of instability is very sensitive to the interface deformation.