1998 Fiscal Year Final Research Report Summary
Conjugate Natural Convection Heat Transfer
| Project/Area Number |
08650247
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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 |
Thermal engineering
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| Research Institution | Kanazawa University |
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Principal Investigator |
KIMURA Sigeo Kanazawa University, Faculty of Engineering, Professor, 工学部, 教授 (70272953)
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| Co-Investigator(Kenkyū-buntansha) |
KIWATA Takahiro Kanazawa University, Faculty of Engineering, Associate Professor, 工学部, 助教授 (40225107)
UENO Hisanori Kanazawa University, Faculty of Engineering, Professor, 工学部, 教授 (80019752)
OKAJIMA Atsushi Kanazawa University, Faculty of Engineering, Professor, 工学部, 教授 (80013689)
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| Project Period (FY) |
1996 – 1998
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| Keywords | Heat Transfer / Natural Convection / Conjugate Heat Transfer / Unsteady Flow / Rayleigh number / Nusselt number / Numerical Analysis / Flow Visualization |
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| Research Abstract |
There have been many works about natural convection heat transfer The thermal conditions on the solid surface are assumed to be isothermal or constant flux in most cases. However, this situation can not occur in reality unless a set of certain thermal and hydrodynamic conditions is fulfilled. In convective heat transfer problems the thermal condition at the solid surface can not be determined apriori, but it must be obtained as a part of the temperature solution. One of the most fundamental problems is to evaluate heat transfer from a heated vertical plate in a still fluid. In view of conjugate problem, we assume that one surface of the plate is heated with a constant temperature and the other is exposed to the fluid. One-dimensional theory is developed for the unknown surface temperature. A 5^<th> order algebraic equation for the unknown surface temperature is then derived. The mean heat transfer rate, the Nusselt number, is then obtained as a product of the apparent Rayleigh number a
… More
nd the average surface temperature. An experimental verification of the one-dimensional theory is also conducted using a water vessel with a heated wall installed on one of the vertical walls. The heat transfer rates from the wall to the water and the average surface temperature are measured. The experimental results are well compared with the theoretical prediction. Another problem that we studied is a case where two convecting reservoirs are separated by a vertical partition of finite conductivity An average heat transfer rate and the mean temperatures of the partition surfaces are obtained theoretically using a similar one-dimensional approach described above. An experiment is also carried out in order to test the proposed theory A marked nature of the present one-dimensional theory lies in its simplicity and its power to incorporate all the conditions (parameters) involved in the problem. The problem was extended to water-glycerin and water-porous systems. It is experimentally proved that the theory works equally well for these extended cases. Forced convection over a horizontal plate and conjugate natural convection problems for various geometries have been investigated in a similar manner. Heat loss from a geothermal wall bore to surrounding rock formation is also studied. Less
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