1999 Fiscal Year Final Research Report Summary
Analysis of double-diffusive convection during crystallization using a simultaneous measurement of temperature and concentration fields
| Project/Area Number |
10650741
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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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 | Toyama University |
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Principal Investigator |
MIYASHITA Hisashi Toyama Univ., Dept. of Mech. Eng., professor, 工学部, 教授 (80019166)
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| Co-Investigator(Kenkyū-buntansha) |
YOSHIDA Masamichi Toyama Univ., Dept. of Mech. Eng., assistant professor, 工学部, 助教授 (70230761)
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| Project Period (FY) |
1998 – 1999
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| Keywords | Double-Diffusion / Natural Convection / Visualization / Heat Transfer / Mass Transfer / Laser Holography / LIF |
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| Research Abstract |
Double-diffusive convection in NaィイD22ィエD2COィイD23ィエD2 aqueous solutions stratified in two layers when destabilized by lateral heating and cooling was investigated using visualization of temperature field and measurement of local concentration. In view of the behavior of the interface between the two layers, the double-diffusive process can be divided into a period of interface formation, a quasi-steady period and a period of unsteady interface. The breaking time of the interface is in linear relation with the buoyancy ratio. The transfer rate of solute depends on the thermal Rayleigh number in the quasi-steady period.
Moreover, a basic study was performed to develop a simultaneous measurement system of temperature and concentration fields using He-Ne laser holographic interferometry (HI) in combination with Ar laser-induced fluorescence (LIF). When HI is applied to double diffusive convection where thermal and solutal gradients coexist, interference fringes representing contour lines of reflective index cannot be considered as isotherms. However, it was found that interference fringes can be considered as contour lines of density except in the neighborhood of the boundary and the interface. Values of reflective index obtained from visualized images were reasonable. Considering this, local concentrations at given times were determined using HI images and measured local temperatures.
For the purpose of development of techniques obtaining the temperature field, the visualization of temperature field in a liquid phase using LIF was performed. Through the analysis of the tristimulus values (RGB) of the fluorescence image, it was found that the change in the brightness of red is linear with temperature and depends on output power of laser. The quantification of LIF images become possible by using these relations.
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Research Products
(12 results)
