Boiling heat transfer in reduced gravity during quenching of a hot surface with R-113

Book · Sun Dec 31 04:00:00 EST 1995

OSTI ID:516814

Xu, J J; Adham-Khodaparast, K; Kawaji, M ^[1]

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1. Univ. of Toronto, Ontario (Canada). Dept. of Chemical Engineering and Applied Chemistry

An experimental study of the flow boiling heat transfer characteristics under microgravity conditions is presented. The experiments were conducted using R-113 by rewetting a heated bottom plate of a rectangular channel, 40 mm wide, 5 mm high and 200 mm long, aboard the KC-135 parabolic aircraft. The local surface heat flux and temperature were measured by a 2-{micro}m thick micro sensor directly fabricated on the surface of the heated plate. The film boiling heat transfer coefficients in microgravity were 70% to 80% of the values in normal gravity, and the results in both gravity conditions showed reasonable agreement with the predictions of Bromley (1953) correlation. Under microgravity, the flow rate had less effect but subcooling had a significant effect on nucleate boiling heat transfer. The effect of microgravity is similar to that due to the absence of subcooling in normal gravity, because both result in a thicker and more stable vapor layer. Also, the nucleate boiling regime covered a wider range of wall superheat below the maximum heat flux in the absence of gravity or subcooling than in the case of high subcooling and normal gravity.

• OSTI ID: 516814
• Report Number(s): CONF-950828--; ISBN 0-7918-1704-0
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
EXPERIMENTAL DATA
FILM BOILING
HEAT TRANSFER
NUCLEATE BOILING
REFRIGERANTS
SUBCOOLED BOILING
TRANSITION BOILING
TWO-PHASE FLOW
WEIGHTLESSNESS