TY - GEN
T1 - A photographic study on the effects of hydrophobic-spot size and subcooling on local film boiling
AU - Suroto, Bambang Joko
AU - Tashiro, Masahiro
AU - Hirabayashi, Sana
AU - Hidaka, Sumitomo
AU - Kohno, Masamichi
AU - Takahashi, Koji
AU - Takata, Yasuyuki
PY - 2013/12/1
Y1 - 2013/12/1
N2 - The effects of hydrophobic circle spot size and subcooling on local film boiling phenomenon from the copper surface with single PTFE (Polytetrafluoroethylene) hydrophobic circle spot at low heat flux has been investigated. The experiments were performed using pure water as the working fluid and subcooling ranging from 0 and 10K. The heat transfer surfaces are used polished copper block with single PTFE hydrophobic circle spot of diameters 2, 4 and 6 mm, respectively. A high-speed camera was used to capture bubble dynamics and disclosed the sequence of the process leading to local film boiling. The result shows that local films boiling occurs on the PTFE circle spot at low heat flux and was triggered by the merging of neighboring bubbles. The study also showed that transition time required for change from nucleate boiling regime to local film boiling regime depends on the diameter of the hydrophobic circle spot and the subcooling. A stable local film boiling occurs at the smallest diameter of hydrophobic spot. Subcooling cause the local film boiling occur at negative superheat and oscillation of bubble dome.
AB - The effects of hydrophobic circle spot size and subcooling on local film boiling phenomenon from the copper surface with single PTFE (Polytetrafluoroethylene) hydrophobic circle spot at low heat flux has been investigated. The experiments were performed using pure water as the working fluid and subcooling ranging from 0 and 10K. The heat transfer surfaces are used polished copper block with single PTFE hydrophobic circle spot of diameters 2, 4 and 6 mm, respectively. A high-speed camera was used to capture bubble dynamics and disclosed the sequence of the process leading to local film boiling. The result shows that local films boiling occurs on the PTFE circle spot at low heat flux and was triggered by the merging of neighboring bubbles. The study also showed that transition time required for change from nucleate boiling regime to local film boiling regime depends on the diameter of the hydrophobic circle spot and the subcooling. A stable local film boiling occurs at the smallest diameter of hydrophobic spot. Subcooling cause the local film boiling occur at negative superheat and oscillation of bubble dome.
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U2 - 10.1115/ICNMM2013-73069
DO - 10.1115/ICNMM2013-73069
M3 - Conference contribution
AN - SCOPUS:84892666936
SN - 9780791855591
T3 - ASME 2013 11th International Conference on Nanochannels, Microchannels and Minichannels, ICNMM 2013
BT - ASME 2013 11th International Conference on Nanochannels, Microchannels and Minichannels, ICNMM 2013
T2 - ASME 2013 11th International Conference on Nanochannels, Microchannels and Minichannels, ICNMM 2013
Y2 - 16 June 2013 through 19 June 2013
ER -