2002 Fiscal Year Final Research Report Summary
Numerical Simulations for Highly Nonlinear Behavior of a Ship in Large-Amplitude Waves
| Project/Area Number |
12450403
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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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 |
KASHIWAGI Masashi Kyushu University, Res. Inst. For Appl. Mech., Professor, 応用力学研究所, 教授 (00161026)
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| Co-Investigator(Kenkyū-buntansha) |
IWASHITA Hidetsugu Hiroshima University, Faculty of Engineering, Assoc. Professor, 工学研究科, 助教授 (60223393)
KYOZUKA Yusaku Kyushu University, Interdisciplinary Graduate School, Professor, 総合理工学研究所, 教授 (80177948)
HU Chunghong , 助教授 (20274532)
TAKAGI Ken Osaka University, Faculty of Engineering, Assoc. Professor, 工学研究科, 助教授 (90183433)
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| Project Period (FY) |
2000 – 2002
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| Keywords | Nonlinear problems / Computational Fluid Dynamics / CIP method / Wave breaking / Wave impact / Time - domain problem / Large-amplitude motion / Added resistance in waves |
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| Research Abstract |
(1) A numerical calculation program was developed for simulating the multi-phase flow with gas, liquid and solid. This program is based on the CIP-CUP method, which is featured in less numerical diffusion and being capable of solving the compressible and incompressible fluids simultaneously with the same equations. The wave impact problem was studied as a check of the program and we found the program very versatile even for the breaker and splash occurring.
(2) Comparison between numerical results and corresponding experiments was made for the impulsive pressure and resultant force acting on a platform fixed above the still water due to a large-amplitude soliton wave. Good agreement was confirmed not only for this case but also for complicated interactions between the green water coming onto the deck of a L-shaped structure and the reflected waves on the deck.
(3) A numerical wave tank was established, with a plunger-type or flap-type wavemaker installed and the numerical absorbing beach to prevent the wave reflection. Then numerical simulations were performed in this numerical wave tank for the nonlinear motions of a floating body caused by large-amplitude waves. It was confirmed that the drift force and impulsive wave force were successfully computed and the computations were very versatile.
(4) By means of the 3-D time-domain Green function method, the so-called body nonlinear calculation method was studied. The wave-induced motion and the added resistance in waves were successfully predicted even for an actual ship with flare near the bow, which was found to be in good agreement with experiments.
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