Comparison between modelled and measured heat transfer rates during the departure of a steam bubble from a solid surface
File(s)
Accepted version
Author(s)
Giustini, G
Kim, Iljin
Kim, Hyungdae
Type
Journal Article
Abstract
This paper presents analysis of the heat transfer attendant upon the departure of a single steam bubble during pool boiling of water at atmospheric pressure. The flow of heat from a solid surface to liquid water during and immediately after bubble lift-off has been extracted from micro-scale measurements of the spatial and temporal variation of the temperature at the solid surface beneath the bubble. The numerical procedure used to extract the heat flux from the temperature variations at the solid surface has been assessed and verified, and applied to investigate the heat transfer during the bubble departure phase, and after the eventual bubble lift-off. Results confirm that fluid motion activated by a departing bubble is the cause of heat transfer enhancement. The phenomenon can be characterised as the process of rewetting, by an advancing liquid front, of a dry portion of wall area at the base of the bubble. The portion of wall area that is affected by the observed heat transfer augmentation mechanism has been found to be that of a circle of diameter roughly equal to half the bubble departure diameter. The current measurements enabled validation of interface-capturing numerical simulation of the hydrodynamics and heat transfer of single bubble formation and departure from a surface, including conjugate heat transfer in the solid substrate. From simulation results, the spatial and temporal variation of the heat flux at the solid surface beneath the bubble has been computed and monitored during bubble departure and after the eventual bubble lift-off. Heat transfer rates at bubble departure extracted from simulation have been found in good agreement with measurements. The simulation correctly captured experimental trends and was found to give an accurate estimate of the magnitude of the flows of heat to the liquid due to the bringing of cold fluid in the vicinity of the wall caused by the bubble departure process.
Date Issued
2020-02-01
Date Acceptance
2019-11-21
Citation
International Journal of Heat and Mass Transfer, 2020, 148
ISSN
0017-9310
Publisher
Elsevier BV
Journal / Book Title
International Journal of Heat and Mass Transfer
Volume
148
Copyright Statement
© 2019 Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence http://creativecommons.org/licenses/by-nc-nd/4.0/
Identifier
https://www.sciencedirect.com/science/article/pii/S0017931019354286?via%3Dihub
Subjects
01 Mathematical Sciences
09 Engineering
02 Physical Sciences
Mechanical Engineering & Transports
Publication Status
Published
Article Number
ARTN 119092
Date Publish Online
2019-11-28