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Visualization study of flow condensation in hydrophobic microchannels
Author(s) -
Chen Yongping,
Shen Chaoqun,
Shi Mingheng,
Peterson George P.
Publication year - 2014
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.14319
Subject(s) - reynolds number , hydraulic diameter , flow visualization , condensation , flow (mathematics) , microchannel , mechanics , materials science , inlet , contact angle , chemistry , thermodynamics , composite material , nanotechnology , turbulence , mechanical engineering , physics , engineering
A visualization study on flow condensation in hydrophobic rectangular silicon microchannels with hydraulic diameter of approximately 150 μm is conducted. Thin Au film with thickness of 200 nm is sputtered on channel surfaces to create a hydrophobic surface with an equilibrium contact angle of approximately 96°. In addition to traditional droplet flow, droplet‐annular compound flow, droplet‐injection compound flow, and droplet‐bubble/slug compound flow are also observed. The results indicate that injection location is postponed, and injection frequency increases with increasing inlet vapor Reynolds number and condensate Weber number. An empirical correlation of the injection location and injection frequency are presented and discussed. In particular, for a larger inlet vapor Reynolds number, the injection flow is closer to the channel outlet and the condensation heat transfer is enhanced. © 2014 American Institute of Chemical Engineers AIChE J , 60: 1182–1192, 2014