| Project/Area Number |
11694176
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
化学工学一般
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| Research Institution | Waseda University |
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Principal Investigator |
HIRATA Akira Waseda University, School of Science and Engineering, Professor, 理工学部, 教授 (00063610)
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| Co-Investigator(Kenkyū-buntansha) |
KINOSHITA Atsuhiro Japan Society for the Promotion of Science, Research Fellow, 特別研究員
MURAKAMI Yoshihiko RIKEN, Bioengineering Laboratory, Special Doctoral Researcher, バイオ工学研究室, 基礎科学特別研究員 (00339748)
TSUNEDA Satoshi Waseda University, School of Science and Engineering, Assistant Professor, 理工学部, 助教授 (30281645)
新船 幸二 早稲田大学, 理工学部, 助手 (10318777)
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| Project Period (FY) |
1999 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥6,500,000 (Direct Cost: ¥6,500,000)
Fiscal Year 2001: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 2000: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1999: ¥2,500,000 (Direct Cost: ¥2,500,000)
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| Keywords | Marangoni convection / surface tension driven convection / microgravity / crystal growth / numerical simulation / melt / 微小重力環境 / 熱流束 / 落下塔 / 残存重力 / 拡散係数 / Long Capillary法 |
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| Research Abstract |
Marangoni convection in the melt is investigated for improvement of the quality of the single crystal grown from a melt. The Marangoni convection in a liquid bridge was investigated the mechanism of the transition process from two-dimensional steady flow to three-dimensional periodic flow through three-dimensional steady flow with increasing of the driving force of the thermally induced surface tension difference. The comparison of the results of the drop shaft experiments and the normal-gravity experiments cleared that the super steady region that is observed under normal-gravity conditions vanished under micro-gravity conditions. The temperature frequency in a liquid bridge induced by Marangoni convection classified into following types : steady, periodically pulsating, periodically rotating, quasi-periodic, and complex. We derived the model equations for the temperature oscillation patterns. The equations agree well with the experimental results. The equation clarified the features
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of each temperature fluctuation types. The transition process of the temperature fluctuation types depends on the shape and volume of the liquid bridge and/or the gravity level.
Local heat flux on the solid-liquid interface was investigated numerically through the step change of the gravity level from 1G to micro-G induced by the drop shaft. The numerical results agree well with the experimental ones. This shows the numerical analysis explains well the heat transfer phenomena in liquid bridges. The heat flux distribution on the solid-liquid interface could be explained commonly by the combination of the following non-dimensional values : the position normalized by the liquid bridge length, Marangoni number and Prandtl number. The numerical simulation clarified the effect of remain gravity on gravity convection in the melt under Long Capillary method.
These results clarified the mechanisms of the Maranogni convection in the melt. Therefore they are useful for improvement of the quality of the grown crystal from a melt. Less
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