An investigation on dynamic thickness of a boiling liquid film
2015 (English)In: International Journal of Heat and Mass Transfer, ISSN 0017-9310, E-ISSN 1879-2189, Vol. 90, 636-644 p.Article in journal (Refereed) Published
Motivated by understanding the micro-hydrodynamics of boiling heat transfer and the mechanism of critical heat flux (CHF) occurrence, the present study is to investigate the boiling phenomenon in a liquid film whose dynamic thickness is recorded by a confocal optical sensor with the measurement accuracy of micrometres, while the bubble dynamics of the boiling in the film is visualized by a high-speed photography. This paper is focused on a statistical analysis of the measured thickness signals for the boiling condition ranging from low heat flux to high heat flux (near or at CHF). The dynamic thickness of liquid film appears oscillating with peak values, resulting from the liquid film movements due to nucleation of bubble(s) and its growth and rupture. The statistical analysis in a certain period indicates there emerge three distinct liquid film thickness ranges: 0-50 μm, 50-500 μm and 500-2500 μm, seemingly corresponding to the microlayer, macrolayer and bulk layer. With increasing heat flux to a specific extent, the bulk layer disappears, and then the macrolayer gradually decreases to ∼105 μm, beyond which the liquid film may lose its integrity and CHF occurs at 1.563 MW/m2.
Place, publisher, year, edition, pages
2015. Vol. 90, 636-644 p.
Boiling, CHF, Film thickness measurement, Liquid film dynamics, Macrolayer, Microlayer, Boiling liquids, Film growth, Film thickness, Heat transfer, High speed photography, Liquid films, Liquids, Statistical methods, Thickness measurement, Boiling conditions, Boiling heat transfer, Critical heat flux(CHF), Macrolayers, Measurement accuracy, Heat flux
IdentifiersURN: urn:nbn:se:kth:diva-175022DOI: 10.1016/j.ijheatmasstransfer.2015.07.011ISI: 000365361400063ScopusID: 2-s2.0-84937064582OAI: oai:DiVA.org:kth-175022DiVA: diva2:876741
QC 201512042015-12-042015-10-092016-01-07Bibliographically approved