低プラントル数流体の半ゾーン液体ブリッジにおける熱毛細管流の実験的研究
| Autor: | Otaka, Masahiko, Takagi, Katsuhiko, Natsui, Hidesada, Arai, Tatsuya, Yoda, Shinichi |
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| Jazyk: | angličtina |
| Rok vydání: | 2001 |
| Předmět: | |
| Zdroj: | 宇宙開発事業団技術報告: Marangoni Convection Modeling Research: Annual Report April 1, 2000 - March 31, 2001 = NASDA Technical Memorandum: Marangoni Convection Modeling Research: Annual Report April 1, 2000 - March 31, 2001. :145-180 |
| ISSN: | 1345-7888 |
| Popis: | The first and clear experimental evidence for the transition from the steady to the oscillatory flow was presented by the non-contact temperature measurement of a molten tin surface and the surface flow visualization. Imaishi et al. confirmed validity of the experimentally determined Ma(sub c2) and frequency of the standing wave in comparison with a numerical result. Some performance tests for radiation thermometer also made this experimental result reliable and accurate. The effect of an aspect ratio (As) on the Ma(sub c2) has been studied. The Ma(sub c2) increases with decreasing of As in the range of As near 1.24. Internal temperature field of liquid bridge at oscillatory flow was speculated by the phase relation analysis of the simultaneous multi-measurement data of surface temperature. The numerical simulation was conducted under the same conditions of the experiment in order to check the onset point and temperature fluctuation data obtained by the experiment. The surface tension of molten tin was measured at various temperatures between 523 and 1023 K under the oxygen partial pressures (P(sub O2)) between 10(exp -19) and 10(exp -6) MPa. It was clarified an appropriate value of the surface tension coefficient for experimental chamber is - 0.9 x 10(exp -4) N/mK. It was also found that the temperature coefficient of surface tension at a constant P(sub O2) raised as P(sub 02) increased, and the sign of the coefficient changed from minus to plus at logP(sub 02) = -9.375 MPa. Visualization technique (3D-UV) of flow field measurements for liquid metals using ultrasonic transducer with high heat resistance has been successively developed for the experiments. Sensitivity of transducer was examined at high temperature condition same as actual thermocapillary experiment. High spatial resolution in the direction of ultrasonic propagation was obtained. Visualization performance of ongoing sensor design was confirmed by numerical simulation. The tracer is also currently under development. Technique for improvement of sphericity and surface roughness was developed. Endurance against molten tin and acoustic characteristics of trial production were experimentally examined. 資料番号: AA0032601006 レポート番号: NASDA-TMR-010015E |
| Databáze: | OpenAIRE |
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