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ISSN Online: 2377-424X

ISBN CD: 1-56700-226-9

ISBN Online: 1-56700-225-0

International Heat Transfer Conference 13
August, 13-18, 2006, Sydney, Australia

BUBBLE LIFT-OFF IN FORCED CONVECTIVE SUBCOOLED BOILING FLOW

Get access (open in a dialog) DOI: 10.1615/IHTC13.p28.210
12 pages

要約

Bubble lift-off is different from bubble departure, and it is more suitable for the boundary condition for numerical simulation of subcooled boiling flow. A force balance analysis of a growing bubble was performed to predict the bubble lift-off size. The dimensionless form of the bubble lift-off diameter was formulated to be a function of Jacob number and Prandtl number. The modeling of bubble lift-off frequency requires careful study of bubble collapse during sliding. Forced convective subcooled boiling flow experiments were conducted in a BWR-scaled vertical upward annular channel. Water was used as the testing fluid, and the tests were performed at atmospheric pressure. A high-speed digital video camera was applied to capture the dynamics of the bubble nucleation process. Bubble lift-off diameters and lift-off frequencies were obtained from the images for a total of 92 test conditions. The bubble lift-off frequency was found to be same as the bubble departure frequency. The proposed bubble lift-off diameter model agreed well with the experimental data within the averaged relative deviation of ±33.6 %.