1995 Fiscal Year Final Research Report Summary
Bubble Formation under Microgravity
| Project/Area Number |
06650865
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
化学工学一般
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| Research Institution | Keio University |
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Principal Investigator |
TSUGE Hideki Keio University Fac.of Science and Techonology Professor, 理工学部, 教授 (70051688)
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| Co-Investigator(Kenkyū-buntansha) |
TERASAKA Koichi Keio University Fac.of Science and Techonology Assistant Professor, 理工学部, 専任講師 (00245606)
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| Project Period (FY) |
1994 – 1995
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| Keywords | Microgravity / Bubble / Bubble formation / Bubble formation mode |
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| Research Abstract |
For the basic design of chemical prants in space stations and on plantes except the earth, few chemical engineering deta have been known. For gas-liquid contacting equipment, such as fermentors, gas absorbers or chemical ractors opectors under microgravity conditions, it is important to make clear the effencts of various factors on the volume and shape of bubble formed at orifices or nozzles. To clarify the behavior of bubble formation in quiescent liquids under microgravity, the effects of gas flow rate and sturface tension on bubble formation were investigated experimentally during 10 seconds by the drop shaft of JAMIC (Japan Microgravity Center) at Kamisunagawa in Hokkaido. To describe theoretically bubble formation in quiescent liqiods under microgravity, the non-sperical bubble formation model proposed by the authors was used ant the calculated results of bubble volume were compared with the experimental ones. It is predicted by this model that bubble volume increases under constant flow condition and a bubble does not detach from a nozzle when gas flow rate is small in quiescent liquid. These calculated resurts of bubble volume agreed well with the experimental ones.
To disperse bubbles uniformly in the liquid, bubbles were formed in flowing liquids under microgrkavity, and the effects of liquid velocity and the direction of gas-liquid flows, that is, cocurrent and crosscurrent flows, on the bubble volume were determined experimentally.
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