Abstract
The prediction of flow boiling is essential owing to its broad applications and complexity. However, the characteristics of flow boiling have not been fully elucidated. In particular, the selection of a model for the bubble lift-off diameter on which the evaporative heat flux is described by a cubic dependence remains ambiguous. In this study, we measure the bubble lift-off diameter on a flat heated surface in a vertical square channel under subcooled flow boiling conditions. Experiments are performed at the atmospheric pressure for mass fluxes of 75–200 kg/m2s, heat fluxes of 50–300 kW/m2, and an inlet subcooling degree of 4.5 K using demineralized water. Bubbles are categorized into lifting-off and ejecting bubbles based on their detaching behaviors from the wall. More than 1600 bubbles are analyzed to measure the lift-off diameter and lift-off velocity. The experimental results show a significant difference in the bubble lift-off diameter between the two types of bubbles mentioned above. We propose a modified model of the bubble lift-off diameter that can predict the average size based on the population ratio of each group.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: International Communications in Heat and Mass Transfer
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
