1987 Fiscal Year Final Research Report Summary
Reynolds Stress and Heat Flux Models for Prediction Flow and Heat Transfer in Engines
| Project/Area Number |
61550156
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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 | Nagoya Institute of Technology |
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Principal Investigator |
NAGANO Yastuaka Dept. of Mech. Eng., Nagoya Institute of Technology, 工学部, 教授 (20024325)
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| Co-Investigator(Kenkyū-buntansha) |
TAGAWA Masato Dept. of Mech. Eng., Nagoya Institute of Technology, 工学部, 助手 (80163335)
TSUJI Toshihiro Dept. of Mech. Eng., Nagoya Institute of Technology, 工学部, 助教授 (90110262)
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| Project Period (FY) |
1986 – 1987
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| Keywords | Reynolds Stress Model / Heat Flux Model / Engine-like Flow / Teiple Product / Probability Density Function / キュムラント展開法 |
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| Research Abstract |
To develop a closure model of diffusion transport in the Reynolds stress andheat flux equations, various types of moments of velocity and temerature fluctuations of the first to the fourth order have been measured and analyzed. First,and orthogonal series expansion for the three-dimensional joint probability density function (pdf) is developed using the cumulants and Hermite polynomials. This pdf is found to provide satisfactory predictions for the statistical characteristics, including triple products, of turbulent momentum and heat transfer. Next, the conditional sampling and averaging technique is employed to investigate the statistical characteristics of coherent turbulent transfer processes of momentum and heat. Conditional pdfs are developed for various moments of velocityand temperature up to the third order. It is showm that the present pdfs can represent the detailed role of coherent motions in the dynamics of wall turbulentshear flows and in the relevant process of heat transport by turbulence. In particular, the importance of coherent motions in the turbulent diffusion process of Reynolds stress components and heat fluxes is demonstrated for the first time by the present theory.
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