1998 Fiscal Year Final Research Report Summary
Development of Fast Numerical Method to Solve Nongray Radiative Heat Transfer in Three-dimensional Arbitrary Shaped Systems by Pre-calculating Geometrical Characteristics
| Project/Area Number |
09555068
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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 | 展開研究 |
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| Research Field |
Thermal engineering
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
KUDO Kazuhiko Grad.School of Eng., Hokkaido Univ., Pro., 大学院・工学研究科, 教授 (40142690)
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| Co-Investigator(Kenkyū-buntansha) |
OGUMA Masahito Ishikawajima Harima Heavy Ind.Co.Ltd.Research Lab.Manager, 専門課長
NAKAMURA Tsuneaki Ltd.Energy Research Lab., Tokyo Gas Co., Manager, エネルギー技術研究所, チームリーダー
MOCHIDA Akeno Grad.School of Eng., Hokkaido Univ., Inst., 大学院・工学研究科, 助手 (50241352)
KURODA Akiyoshi Grad.School of Eng., Hokkaido Univ., Assc.Pro., 大学院・工学研究科, 助教授 (90202051)
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| Project Period (FY) |
1997 – 1998
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| Keywords | RADIATAIVE HEAT TRANSFER / NUMERICAL ANALYSIS / NONGRAY / FURNACE / BOILER / HEATING FURACE |
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| Research Abstract |
The objective of this research is to develop a threed-dimensioal nongray radiative-convective heat transfer program for arbitrary shaped systems. For the purpose, new fast algorithm for numerical analysis on nongray radiative heat transfer is developed and confined with a threed-dimensioal nongray radiative-convective heat transfer program for arbitrary shaped systems..
In the study, the Monte Carlo method is adopted for the analytical tool for the radiative transfer calculation. As the method is known to be time-consuming, below mentioned unique fast algorithm for numerical analysis on nongray radiative heat transfer is proposed to avoid the repeated use of the method for the times of (number of wave number division)x(number of iterational calculations for temperature convergence).
The variables used in the radiative heat transfer analysis are the functions of non-dimensional "optical thichness" which is the product of physical length and absorption coefficient of gas layer. As the valu
… More
e of the absorption coefficient depends on the temperature and the wave number, the value of the optical depth is not the unique value of the system. Considering that this characteristics of the optical depth is the cause of the necessity of the repeated calculation in nongray analysis, an idea is presented in which optical depth is divided into two parts, physical length between calculational elements and the absorption coefficient. Exploiting that the physical lengths between elements are unique value of the system and do not depend the temperature and wave number the values can be calculated outside the caluculational loop for temperature convergence using the Monte Carlo method. Then, every time when the optical depth is needed in the iteratinal loop, it can easily calculated as the product of the pre-calculated physical lengths and the tentative value of absorption coefficient which depends on the temperature.
Owing to the development of the above mentioned method, multiple usage of the time consuming Monte Carlo calculation can be waved, and the total calculating time is reduced to 1/6 for the same accuracy. Less
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