1988 Fiscal Year Final Research Report Summary
Flow field around Ships with 3D Separation Vortices and Its Relationships with Ship Form
| Project/Area Number |
62460147
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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 |
船舶抵抗・運動性能・計画
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| Research Institution | Osaka University |
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Principal Investigator |
TANAKA Ichiro Faculty of Engineering, Osaka University, 工学部, 教授 (30028964)
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| Co-Investigator(Kenkyū-buntansha) |
TODA Yasuyuki Faculty of Engineering, Osaka University, 工学部, 助手 (20172166)
MATSUMURA Kiyoshige Faculty of Engineering, Osaka University, 工学部, 助手 (10135668)
SUZUKI Toshio Faculty of Engineering, Osaka University, 工学部, 教授 (80029107)
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| Project Period (FY) |
1987 – 1988
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| Keywords | Separation vortex / Frame lines / Thick Boundary Layer theory / 砕波 |
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| Research Abstract |
The objective of the research is firstly, to investigate into the mechanism of generation of 3D separation vortices around ship hull and the relationship between the vortices and hull form. The second objective is to explore the methods of calculation of flow field around the hull as well as fluid dynamical forces on it, considering its effect of vortices. The contents of the research and conclusions are as follows:
1. A metod of calculation of flow field around ships running obliquely has been developed. Storong dependence of separation on concaveness of frame lines is pointed out.
2. In the above-obtained method, it is necessary to know the initial form of the separation vortex. To obtain it, a perturbation method is developed for the flow field near separation of a cone based on the self-simirality concept. It is found that the calculated form of vortex at the infinitely large reynolds number is differnt from the one observed at finite reynolds number.
3. Using the thick boundary layer thery and a simple propeller theory, a method of calculation of flow field around ships is deloped. It is shown that the results of calculation show good coincidence with the results of experiments.
4. The breaking wave flow field near the bow is analytically studied with the assumption of low froude number. It is found that the local wave without separation vortex is fairly coincident to the meassured wave.
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Research Products
(6 results)
