Heat transfer coefficients in bubbly and slug flows under microgravity conditions
- Univ. of Saskatchewan, Saskatoon (Canada). Mechanical Engineering Dept.
- Trane, Co., LaCrosse, WI (United States)
Experimental local heat transfer data were collected onboard NASA`s KC-135 reduced gravity aircraft for two-phase, air-water flow in vertical, upward, co-current flow through a 9.53 mm circular tube. It was found that in the bubbly and slug flow regimes (surface tension dominated regimes), reduced gravity has a tendency to lower the heat transfer coefficient by up to 50% at the lowest gas qualities. As the gas quality is increased (transition to annular flow), the difference between the 1-g and {micro}-g heat transfer coefficients is much less significant. Empirical correlations were developed in terms of the pertinent dimensionless groups; namely the superficial liquid Reynolds number, the Froude number, the Graetz number and the Morton number. The correlations predicted the experimental data within 10--25%, depending on the flow regime and the superficial gas Weber number.
- Sponsoring Organization:
- Natural Sciences and Engineering Research Council of Canada, Ottawa, ON (Canada)
- OSTI ID:
- 477350
- Report Number(s):
- CONF-961105--; ISBN 0-7918-1519-6
- Country of Publication:
- United States
- Language:
- English
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