Numerical estimation of wave spectra around an island by using wave diffraction theory
| Project/Area Number |
15360267
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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 |
水工水理学
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
YOSHIDA Akinori Kyushu University, Faculty of Engineering, Associate Professor, 工学研究院, 助教授 (30117288)
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| Co-Investigator(Kenkyū-buntansha) |
YAMASHIRO Masaru Kyushu University, Faculty of Engineering, Research Associate, 工学研究院, 助手 (70336014)
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| Project Period (FY) |
2003 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥6,900,000 (Direct Cost: ¥6,900,000)
Fiscal Year 2004: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 2003: ¥5,600,000 (Direct Cost: ¥5,600,000)
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| Keywords | Islands / Water Wave Diffraction / Wave Spectrum / Frequency Spectrum / Directional Spectrum / Wave Observation / Boundary Element Method / Wave distribution Function / 島陰部 / 係留浮体 |
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| Research Abstract |
We have developed a numerical method to predict water wave spectra at arbitrary points on the sea around an island. The method is based on numerical prediction of the wave field around the island. The wave field is obtained by using known wave diffraction theory on a cylindrical structure of arbitrary cross section in the sea of constant depth. The feature of the method lies in its simplicity in the prediction of wave spectra at any points in comparison with the prediction obtained through field observation.
In this research, the calculation of wave field was first conducted using a boundary element method (BEM). The problems to be taken into consideration in numerical calculations were first investigated. Then, using obtained wave diffractions around the island, wave spectra (directional spectra and frequency spectra) were calculated. Along with the numerical prediction, field observation of waves around an specific island (Shirashima oil storage island, Kitakyushu, Fukuoka, Japan) was carried out from Oct. 2003 to Feb. 2004, and wave spectra were calculated from the obtained wave data. The numerically predicted spectra using the present method were compared with those obtained from field observation. It was confirmed that the effect of scattered waves reaches far from the islands and thus this should be considered in the estimation of incident wave spectra through field observation, and that the present method can give good overall prediction for the wave spectra at arbitrary points around islands.
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Report
(3 results)
Research Products
(3 results)
