2005 Fiscal Year Final Research Report Summary
Theoretical Study on Mechanics and Rheology of Granular Systems
| Project/Area Number |
16540344
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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 |
Mathematical physics/Fundamental condensed matter physics
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
NAKANISHI Hiizu Kyushu University, Dep.Physics, Professor, 理学研究院, 教授 (90155771)
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| Co-Investigator(Kenkyū-buntansha) |
MITARAI Namiko Kyushu University, Dep.Physics, Research Associate, 理学研究院, 助手 (50392139)
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| Project Period (FY) |
2004 – 2005
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| Keywords | granular system / rheology / kinetic theory / pattern formation / phase field model / percolation |
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| Research Abstract |
Rheology of granular system : We have performed DEM (Discrete Element Method) simulations for the granular flow on an inclined slope in order to clarify the source of discrepancy between the results of numerical simulation and those of the kinetic theory. It has been pointed out that the granular density depends on the angle of the slope but is independent of the depth of the flow. This can be understood using the Bagnold scaling combined with the kinetic theory, but the predicted value of the density was increasing function of the slope angle, which is opposite to the simulation results. We have carefully compared the simulation results with the kinetic theory prediction, and have found out that the source of discrepancy is that the kinetic theory overestimates the energy dissipation rate.
Pattern formation in drying process of water-granular mixture : It has been demonstrated by Yamazaki and Mizuguchi that labyrinthine patterns are produced by the drying process of two-dimensional water-granule mixture sandwiched between two glass plates. We have pointed out that the process can be regarded as the small diffusion limit of the crystal growth, namely, the unexplored limit of the well studied problem. In order to understand the mechanism of the pattern formation, we have constructed three types of models : the phase field model, the boundary dynamics, the lattice model based on the invasion percolation ; Each of them are focusing on different aspect of the process.
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Research Products
(7 results)
