Report on Pool Boiling Experiment Flown on STS-47 (PBE-IA), STS-57 (PBE-IB), and STS-60 (PBE-IC). Final report

Technical Report · Fri Mar 01 04:00:00 EST 1996

OSTI ID:404769

Merte, H Jr; Lee, H S; Keller, R B

Experiments were conducted in the microgravity of space in which a pool of liquid (R-113), initially at a precisely defined pressure and temperature, is subjected to a step imposed heat flux from a semi-transparent thin-film heater forming part of one wall of the container such that boiling is initiated and maintained for a defined period of time at a constant pressure level. Transient measurements of the heater surface and fluid temperatures near the surface are made, noting in particular the conditions at the onset of boiling, along with motion photography of the boiling process in two simultaneous views, from beneath the heating surface and from the side. The conduct of the experiment and the data acquisitions are completely automated and self-contained. A total of nine tests were conducted at three levels of heat flux and three levels of subcooling under three essentially identical circumstances in three space experiments designated as PBE-IA, -IB, -IC on the STS-47, -57, -60, respectively. Minor differences in lengths of various components of the experiments were programmed in the three flights. Two of the flights (STS-47, -60) took place with the same physical hardware, while the other (STS-57) used an identically fabricated hardware. The basic mechanisms of pool boiling are reviewed, with particular emphasis on the roles of buoyancy, and the experimental concepts and parameters used are given. The hardware and operating procedures followed are described in some detail. The experimental results for each of the nine runs in each of the space flights, along with those from several post-flight ground tests, are given in sufficient detail that the derived parameters and conclusions can be independently obtained, if desired. Sample images are provided for each run, following digitizing from the 16 mm film. The absence of buoyancy permitted the onset of boiling at low heat flux levels, with what is deemed as homogeneous nucleation taking place.

• Research Organization: Michigan Univ., Ann Arbor, MI (United States)
• OSTI ID: 404769
• Report Number(s): N--96-27393; NASA-CR--198465; E--10154; NAS--1.26:198465; NIPS--96-35673; CNN: NAS3-25812; RTOP 694-03-03
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
HEAT TRANSFER
POOL BOILING
REFRIGERANTS
SPACE FLIGHT
TRANSIENTS