2001 Fiscal Year Final Research Report Summary
Transition to Oscillatory and Chaotic Flows in Marangoni Convection of Liquid Bridge (Towards an On-Orbit Experiment aboard the International Space Station)
| Project/Area Number |
11450089
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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 |
Thermal engineering
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| Research Institution | Tokyo University of Science |
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Principal Investigator |
HIROSHI Kawamura Tokyo University of Science, Fac. Sci. & Tech., Professor, 理工学部, 教授 (80204783)
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| Co-Investigator(Kenkyū-buntansha) |
ICHIRO Ueno Tokyo University of Science, Fac. Sci. &Tech., Research Associate, 理工学部, 助手 (40318209)
KOICHI Suzuki Tokyo University of Science, Fac. Sci. & Tech., Associate Professor, 理工学部, 助教授 (10089378)
KOICHI Nishino Yokohama National University, Fac. Eng., Associate Professor, 工学部, 助教授 (90192690)
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| Project Period (FY) |
1999 – 2001
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| Keywords | Marangoni Convection / Microgravity / Oscillatory Convection / Liquid Bridge / 3D-PTV / Chaos / international Space Station |
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| Research Abstract |
Aiming at an on-orbit experiments aboard the International Space Station(ISS) in 2005, experimental and numerical studies on the Marangoni convection in a half-zone liquid bridge have been carried out. A half-zone liquid was formed between the coaxial cylindrical rods. The temperature difference between the rods induced the thermocapillary convection over the free surface of the bridge. The thermocaPillary-driven flow exhibited a transition from the 2D steady to the 3D 'oscillatory' flows at a critical temperature difference or a critical Marangoni number.
In the present study, a series of experiments was performed in a low temperature environment in order to suppress the evaporation of fluid while realizing a large temperature difference between the both ends of the bridge to attain a high Marangoni number in spite of a small size of the bridge (5mm in diameter and a few mm in height). In addition the three-dimensional particle tracking velocimetry (3-D PTV) was applied to measure the
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3-D flow field of the thermocapillary flow in the small-size liquid bridge. The simultaneous observation with two CCD cameras from the top-end surface was enabled by the application of a small prism placed above the transparent top rod made of sapphire glass. From the series of experiments, following results were obtained ; (1)the critical condition of the transition and the modal strucure after the transition were evaluated as a function of the liquid bridge diameter, aspect ratio and the fluid viscosity, (2)the 3-D velocity fields of the steady and oscillatory flows were reconstructed by 3-D PTV, (3)new types of pulsating and rotating oscillatory flows far beyond the critical condition were found and (4)chaotic and turbulent flows were realized and analyzed by the reconstruction of the pseudo-phase space from the surface temperature variation and by the evaluation of the correlation dimension. In addition, following results were achieved in the numerical study ; (1)a numerical code to calculate the flow field of high Pr number fluid at high Ma number was developed, and (2)non-linear analysis of the chaotic and turbulent flows at high Ma number was carried out.
These results contributes significantly for preparation of the on-orbit experiment and establishment of the method analyzing data from the ISS as well as for understanding the fluid dynamics in this system. Less
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Research Products
(10 results)
