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Bubble dynamics in microchannels. Part I: single microchannel
Ist Teil von
International journal of heat and mass transfer, 2004-12, Vol.47 (25), p.5575-5589
Ort / Verlag
Oxford: Elsevier Ltd
Erscheinungsjahr
2004
Quelle
ScienceDirect
Beschreibungen/Notizen
The present work explores experimentally bubble dynamics in a single trapezoid microchannel with a hydraulic diameter of 41.3
μm. The fabrication process of the microchannel employs a silicon bulk micromachining and anodic bounding process. Bubble nucleation, growth, departure size, and frequency are observed using a high speed digital camera and analyzed by the Image-Pro. The results of the study indicates that the bubble nucleation in the microchannel may be predicted from the classical model with microsized cavities and the bubble typically grows with a constant rate from 0.13 to 7.08
μm/ms. Some cases demonstrate an extraordinarily high growth rate from 72.8 to 95.2
μm/ms. The size of bubble departure from the microchannel wall is found to be governed by surface tension and drag of bulk flow and may be fairly correlated by a modified form of Levy equation. The bubble frequency in the microchannel is comparable to that in an ordinary sized channel. The traditional form of frequency–departure-diameter relationship seems to be inexistent in the microchannel of this study.