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Gravity–capillary evaporation regimes in microgrooves
Author(s) -
Zhang Chengbin,
Yu Fawen,
Li Xuejie,
Chen Yongping
Publication year - 2019
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.16484
Subject(s) - capillary action , evaporation , heat pipe , materials science , mechanics , chemistry , composite material , heat transfer , thermodynamics , physics
The gravity–capillary evaporation phase change in microgrooves inside a heat pipe is experimentally investigated by a visualization system. The evaporation regime, startup temperature response, and evaporation thermal resistance for gravity–capillary evaporation are evaluated and compared with those for capillary evaporation. The results identify oscillatory motion of vapor–liquid interface for gravity–capillary evaporation in rectangular microgrooves arising from the competition between gravity, the capillary force, and the shear force. In addition, the presence of gravity introduces the transition from fin–film evaporation regime to corner–film evaporation regime in rectangular microgrooves, and hence results in an overshoot startup and temperature oscillation during the process of gravity–capillary evaporation. Interestingly, the corner–film evaporation improves the evaporation phase change performance in the microgrooves. © 2018 American Institute of Chemical Engineers AIChE J , 65: 1119–1125, 2019