高プラントル数流体の振動熱毛細管流に及ぼす自由表面熱伝達の影響に関する研究
| Autor: | Wang, L., Kamotani, Yasuhiro, Hatta, Sayaka, Yoda, Shinichi |
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| Jazyk: | angličtina |
| Rok vydání: | 2002 |
| Předmět: | |
| Zdroj: | 宇宙開発事業団技術報告: Marangoni Convection Modeling Research: Annual Report April 1, 2001-March 31, 2002 = NASDA Technical Memorandum: Marangoni Convection Modeling Research: Annual Report April 1, 2001-March 31, 2002. :23-41 |
| ISSN: | 1345-7888 |
| Popis: | Oscillatory thermocapillary flow in liquid bridges of high Prandtl number fluid is investigated. The effect of heat transfer at the free surface on the conditions for the onset of oscillations is studied experimentally. In order to vary the surface heat transfer over a wide range, the experiments are conducted in an oven. The surface heat transfer results in net heat loss or net gain depending on the oven temperature relative to the hot wall temperature. The heat loss situation is of main interest in the present work. It is shown that the critical Marangoni number (Ma(sub cr)) increases substantially with decreasing free surface heat loss. The air motion is simulated numerically in order to compute the free surface heat transfer rate. The numerical results show that the critical conditions cannot be correlated by two parameters, Ma and mean Biot number. It is shown that the S-parameter correlates the critical conditions well when the surface heat transfer is minimized. When the free surface gains heat at high oven temperature, the critical temperature difference now decreases with increasing heat gain. How the oscillation mechanism is affected by the free surface heat transfer is discussed. 資料番号: AA0045403001 レポート番号: NASDA-TMR-020026E |
| Databáze: | OpenAIRE |
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