2017 Fiscal Year Final Research Report
Two distinct mechanism for the shear thickening of a dilatant fluid
| Project/Area Number |
15K05223
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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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 | Sendai National College of Technology |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
中西 秀 九州大学, 理学研究院, 教授 (90155771)
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| Project Period (FY) |
2015-04-01 – 2018-03-31
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| Keywords | ずり粘化 / ダイラタント流体 / レオロジー / 懸濁液 |
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| Outline of Final Research Achievements |
A dense mixture of granules and liquid often shows a discontinuous shear thickening (DST) and is called a dilatant fluid. The mechanism of DST is not clear, and the distribution of pressure or viscosity under DST have never been observed. In the present research, we performed numerical simulation and experiment of Taylor-Couette flow of a dilatant fluid and elucidate the space distribution of the viscosity and pressure, i.e. the thickening regions from a fan-shape bands. These bands distinctly has positive and negative pressure, and the bands in stretching (compresssing) direction had negative (possitive) pressure.The pressure in the positive domains increases linearly with the external shear stress, while the negative pressure does not seem to depend on external stress, but remains below the Laplace pressure. As for the nega tive pressure, it should be caused by the fluid in the interstitial space that tends to expand upon deformation of the medium due to Reynolds dilatancy.
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| Free Research Field |
流体物理学
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