DOI: 10.1615/ICHMT.2008.CHT
ISBN Print: 978-1-56700-253-9
ISSN: 2578-5486
COARSE-GRAINED MICRO-HYDRODYNAMICS SIMULATION OF HIGH HEAT-FLUX BOILING USING THE CMFD CODE TransAT
SINOPSIS
This paper presents results of numerical simulation of processes that govern a specific case of nucleate boiling heat transfer at high heat fluxes using the level set method. The model used for the purpose is a coarse-grained approach whereby the phase-change induced evaporation rate is incorporated like a sub-grid scale heat transfer model (SGS-HT), applied to the triple contact line. The evaporation rate is varied over a range that reflects conditions of experiments performed in a recent test campaign BETA-B [Dinh and Tu 2007]. The SGS-HT model was compared to results obtained with a model in which evaporation occurs uniformly over the entire bubble wall (interface). The two models, contact line evaporation vs. bubble wall evaporation, show qualitatively different behaviour of bubble growth dynamics. Comparison with visual images from the BETA-B experiments suggests that the use of the SGS-HT model is central to capturing micro-hydrodynamics in a boiling thin film, at least qualitatively.