1995 Fiscal Year Final Research Report Summary
Study on momentum, heat flux and substance exchange between atmosphere & ocean
| Project/Area Number |
06302067
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| Research Category |
Grant-in-Aid for Co-operative Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
海洋工学
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| Research Institution | Kyushu University |
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Principal Investigator |
KOTERAYAMA Wataru Kyushu Univ., Res.Inst.for Applied Mechanics, Professor, 応用力学研究所, 教授 (80038562)
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| Co-Investigator(Kenkyū-buntansha) |
YOSHIDA Kouichitou Tokyo Univ., Faculty of Engineering, Professor, 工学部, 教授 (90010694)
MAEDA Hisaaki Tokyo Univ., Inst., of Industrial Science, Professor, 生産技術研究所, 教授 (80013192)
IKEDA Yoshiho Univ.of Osaka Prefecture, Faculty of Engineering, Assistant Professor, 工学部, 助教授 (10117989)
NAITO Shigeru Osaka Univ., Faculty of Engineering Assistant Professor, 工学部, 助教授 (20093437)
TAKEMATSU Masaki Kyushu Univ., Res.Inst.for Applied Mechanics, Professor, 応用力学研究所, 教授 (50038535)
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| Project Period (FY) |
1994 – 1995
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| Keywords | Surface buoy / Field experiment / Taut mooring / 3-D lumped mass method / Numerical simulation of deployment and retrieval |
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| Research Abstract |
In the field of ocean engineering inertia gyro and accelerometers are used for the motion measurements. This kind of system is reliable it is sometimes too expensive, large power consumption and heavy for the user. In the present study we have developed a motion sensor system composed of piezo-oscillation gyro and accelerometers, which is low cost, low power and light weight and very convenient for a user. Field experiments on a surface buoy system have been carried out at the south of Okinawa Island by using the developed motion sensor system. The buoy system used as research object is a circular buoy, of which the displacement is 50 ton and the diameter 7m, moored at latitude 26 degree north and longitude 128 degree east south of Okinawa. The surge, sway, heave, roll, pitch and yaw motions were measured with the developed motion sensor system. The experimental term was one month from August 4th to September 6th, 1995. We have also measured the wave height and the wave pattern by using wave rider type wave height meter and HF radar. The evaluation of the accuracy of the motion measurements was possible by the help of these wave height measurements.
We have also developed a numerical simulation method for the six degree freedom motions of surface buoy and dynamics of mooring cable based on the lumped mass method.
Main conclusions obtained in this study are as follows ;
1) the accuracy of the developed sensor system for angular measurements was excellent.
2) the method of noise cut for the data of the accelerometer affects on the accuracy of the surge, sway, heave, roll, pitch and yaw motions in the case of small wave height.
The accuracy of motion sensor system and numerical simulation method will be improved through the experiments and mutual comparisons in the future studies.
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