1987 Fiscal Year Final Research Report Summary
Natural convection of a heat-generating fluid confined in a frozen layer within a horizontal cylinder
| Project/Area Number |
61550157
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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 |
Thermal engineering
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| Research Institution | Toyohashi University of Technology |
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Principal Investigator |
MITACHI Kohshi Toyohashi University of Technology Associate Professor, 工学部, 助教授 (90002047)
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| Project Period (FY) |
1986 – 1987
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| Keywords | Natural convection / Unsteady heat transfer / Heat-generating fluid / Freezing / Horizontal cylinder / Numerical analysis / 実験 |
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| Research Abstract |
When the wall of a horizontal cylinder in which a heat-generating fluid is confined is chilled below the freezing point of the fluid, a solid layer is formedon the iner wall surface. Concomitantly, natural convection is induced in the liquid region by the temperature between the liquid and the solid-liquid interface. Such combined phenomenon, for example, will be observed in a dump-tank which is used as a storage vessel of fuel salt when an emergency shut dowm of a molten salt breeder reactor happens. In this project, a study was conducted to clarify the thermal characteristics of this combined phenomenon. The outline of this study was as follow.
1. Unsteady natural convection of the heat-generating fluid in a horizontal cylinder was investigated through the numerical analysis by the finite difference method in the range of Rayleigh number up to 10^8.
2. Temperature profiles and heat transfer coefficients were measured by Mach-Zehnder interferometer with a high accuracy. The results obtained were very much in agreement with the numerical results.
3. Equations to estimate the Nusselt number and the maximum temperature in the cylinder were obtained experimentally in the range of Rayleigh number up to 7X10^<12>.
4. A numerical study by finie difference method was carried out for the solidification of the heat-generating fluid in the horizontal cylinder. Results clarified th characteristics of the frozen layer and the natural convection induced in the liquid region.
5. An approximate method was devised to estimate the thickness of the frozen layer, the maximum temperature, the maximum stream function and the mean Nusseltnumber in the liquid region.
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