1993 Fiscal Year Final Research Report Summary
Statistical Law and Energy Transfer Mechanism in Turbulence
| Project/Area Number |
03452053
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
物理学一般
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
KIDA Shigeo Kyoto Univ., RIMS, Associate Prof., 数理解析研究所, 助教授 (70093234)
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| Co-Investigator(Kenkyū-buntansha) |
MUROTA Kazuo Kyoto Univ., RIMS, Associate Prof., 数理解析研究所, 助教授 (50134466)
OHKITANI Kohji Kyoto Univ., RIMS, Assistant, 数理解析研究所, 助手 (70211787)
TOH Sadayoshi Kyoto Univ., Science, Assistant, 理学部, 助手 (10217458)
OKAMOTO Hisashi Kyoto Univ., RIMS, Associate Prof., 数理解析研究所, 助教授 (40143359)
MIZUSHIMA Jiro Doshisha Univ., Engineering dep., Prof., 工学部, 教授 (70102027)
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| Project Period (FY) |
1991 – 1993
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| Keywords | turbulence / energy transfer / turbulent shear flow / vortical structure / thermal convection / dynamo / compressible turbulence |
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| Research Abstract |
1. It was found in the homogeneous isotropic turbulence that the energy transfer through the trial interaction is local in the inertial range but it is nonlocal in the dissipation range. The former agrees with the Kolmogorov theory while the latter may give a useful suggestion to turbulence modelling. The generation, development and breakdown of various vortical structures in a uniformly sheared turbulence were analyzed in terms of the dynamics of the vorticity vector. The relative importance of the mean flow, advection, nonlinear selfinteraction and viscous terms in the energy transfer process was clarified.
2. The localized structure in the marginal convection state between two rotating spheres was solved. A new bifurcation branch was found as the Reyleigh number is increased. A bunch of Taylor columns with strong helicity were realized by the direct numerical simulation.
3. The mechanism of the energy transfer in a forced compressible turbulence was investigated by analysing the vorticity and density fields. The kinetic energy was divided into the compressible and rotational parts by employing the Helmholtz decomposition. The relative importance of the advection, the baroclinic and the viscous terms in the energy exchange between these components and internal energy was evaluated quantitatively.
4. The mechanism of pattern formation in a Rayleigh-Benard convection was clarified by the weakly nonlinear theory.
5. The statistical law in the complex Ginzburg-Landau turbulence was explained by the interaction between the fundamental solutions.
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