Brunel University Research Archive (BURA) >
College of Engineering, Design and Physical Sciences >
Dept of Mechanical Aerospace and Civil Engineering >
Dept of Mechanical Aerospace and Civil Engineering Research Papers >

Please use this identifier to cite or link to this item: http://bura.brunel.ac.uk/handle/2438/3187

Title: Experimental pool boiling investigations of vertical coalescence for FC-72 on silicon from an isolated artificial cavity
Authors: Hutter, C
Sanna, A
Sefiane, K
Kenning, DBR
Karayiannis, TG
Nelson, RA
Lin, H
Cummins, G
Walton, AJ
Keywords: Nucleate pool boiling
Vertical coalescence
Artificial cavity
Publication Date: 2009
Publisher: Committees of ExHFT-7
Citation: 7th World Conference on Experimental Heat Transfer, Fluid Mechanics and Thermodynamics (ExHFT-7), Krakow, Poland, June 28 - July 03, 2009
Abstract: In this study bubble growth from an isolated artificial cavity micro-fabricated on a horizontal 380 µm thick silicon wafer was investigated. The horizontally oriented boiling surface was heated by a thin resistance heater integrated on the rear of the silicon test section. The temperature was measured using an integrated micro-sensor situated on the boiling surface with the artificial cavity located in its geometrical centre. A resistive track was used as the sensor, which when calibrated, exhibited a near-linear behaviour with increasing temperature. To conduct pool boiling experiments the test section was immersed in degassed fluorinert FC-72. Bubble nucleation, growth and detachment at different pressures were observed using high-speed imaging. Coalescence was observed at the boundary between the isolated bubble and interference regimes. The occurrence of vertical coalescence was found to be more frequent, with increasing wall superheat and decreasing pressure. The equivalent sphere volumes of two bubbles before and after coalescence were evaluated from area measurements. It was observed that the second nucleated bubble is always smaller than its predecessor. The vapour generation appears not to stop during coalescence as the volume of the merged bubble was typically 5-18% larger than the sum of the bubble volumes just before coalescence.
URI: http://bura.brunel.ac.uk/handle/2438/3187
Appears in Collections:Mechanical and Aerospace Engineering
Dept of Mechanical Aerospace and Civil Engineering Research Papers

Files in This Item:

File Description SizeFormat
Experimental+pool+boiling+investigations+of+vertical+coalescence+for+FC-72+on+silicon+from+an+isolated+artificial+cavity.pdf534.72 kBAdobe PDFView/Open

Items in BURA are protected by copyright, with all rights reserved, unless otherwise indicated.