| Project/Area Number |
02640294
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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 |
物理学一般
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| Research Institution | Interdisciplinary Graduate School of Engineering Science, Kyushu University |
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Principal Investigator |
HONJI Hiroyuki Kyushu University, Interdisciplinary Graduate School of Engineering Science, Professor, 大学院・総合理工学研究科, 教授 (80038538)
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| Project Period (FY) |
1990 – 1991
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1991: ¥200,000 (Direct Cost: ¥200,000)
Fiscal Year 1990: ¥900,000 (Direct Cost: ¥900,000)
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| Keywords | Double diffusion / Thermohaline convection / Stratified fluid / Salt finger / Dissipative structure / Turbulence |
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| Research Abstract |
Laminar and chaotic flows occurring in thermolialine double-diffusive systems of fluid flows have been investigated experimentally by means of the nietliod of flow visualization.
A preliminary experiment on the thermolialine convection was made using a double-diffusion tank with a horizontally movable plate for separating upper and lower fluids initially. The inain results obtained are as follows : (1)The measured spacings of salt fingers(horizontal wavelengths)are larger than the values predicted on the basis of linear stability theory. (2)A correlation dimension obtained from the present experiment is about 1.5 for both salt finger type and heat-driven type convictive flows.
An oscillatory flow of brine in a stallow tank has also been investigated exploratively in relation to the double-diffusive convection. The flow is' induced by the interaction between ionic currents and a magnetic field of a pair of peri-nanent magnets. The region of oscillatory wake formation has been clarified in the current-density/Reynold number diagram.
A detailed flow visualization experiment has been further carried out using a 3OX4OX5 cm double-diffusion tank. It has been found that peculiar salt fingers with horizontal spacings broader than those of normal fingers are formed at the stability density ratios R>20. These spacings increase with increasing R. Salt fingers with different upper and lower spacings have been found to form in the tank. Temperature fluctuations in the heat-driven type flows have been found to have more modes than the salt-finger type ones.
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