1998 Fiscal Year Final Research Report Summary
Research on vibration and damages with water-jet propulsion in high speed ships
| Project/Area Number |
09651016
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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 |
船舶工学
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
YASUZAWA Yukitaka Kyushu Univ.Eng.Asscos.Prof., 工学部, 助教授 (10191123)
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| Co-Investigator(Kenkyū-buntansha) |
TOYOTA Kazutaka Kyushu Univ.Eng.Assistant Prof., 工学部, 助手 (10274507)
MAEDA Masahiro Kyushu Univ.Eng.Assistant Prof., 工学部, 助手 (70173713)
KAGAWA Koji Kyushu Univ.Eng.Professor, 工学部, 教授 (00253500)
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| Project Period (FY) |
1997 – 1998
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| Keywords | high speed ship / water-jet / vibration / hydro-elasticity / FEM / BEM |
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| Research Abstract |
Vibration and damages in water-jet propulsion in high speed ships are investigated. Water duct in which water flows fast may reduce the natural frequencies of the duct structures which are pipe structures with rectangular cross section, that is, box girder. In the present study the mechanism of the reduction of natural frequencies are clarified by constructing mechanical models arid calculation of eigen systems. In the formulation finite elements for duct structures and boundary elements for inner flow of water are used.
As the result of the formulation, It has been proved that the flow reduces thestiffness of the fluid-structure coupled system and the reduction matrix is propotional to dencity and the square of the fluid velocity but added mass of water does not depend on the velocity.
Furthermore the features of coupling vibration between adjacent panels or opposite panels due to the internal fluid could be obtained by the developed numerical analysis. The numerical results have been verified by the experiments.
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