Study on characteristics of long-period waves accompanied by irregular sea waves in coastal regions and their directional spectrum

2016 Fiscal Year Final Research Report

• Project/Area Number: 26289166
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Hydraulic engineering
• Research Institution: Kyushu University
• Principal Investigator: Hashimoto Noriaki 九州大学, 工学(系)研究科(研究院), 教授 (90371749)
• Co-Investigator(Kenkyū-buntansha): 藤木 峻 国立研究開発法人港湾空港技術研究所, その他部局等, 研究員 (10735004) ; 川口 浩二 国立研究開発法人港湾空港技術研究所, その他部局等, その他 (50371753) ; 横田 雅紀 九州大学, 工学(系)研究科(研究院), 助教 (60432861) ; 山城 賢 九州大学, 工学(系)研究科(研究院), 准教授 (70336014) ; 伴野 雅之 国立研究開発法人港湾空港技術研究所, その他部局等, その他 (80549204)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 方向スペクトル / 波浪観測 / 海洋波 / 長周期波

Outline of Final Research Achievements

With an upgraded ultrasonic Doppler type directional wave meter (DWM), we carried out multi wave quantity components measurements of water surface elevation and 30 oblique components of water particle velocities at 10 layers in water. First, we examined estimation accuracy of directional spectrum through numerical simulations for the DWM by using several representative analysis methods. Then the directional spectra estimated from field data observed with DWM were investigated for various cases of different combinations of wave quantities to clarify occurrence characteristics of coastal directional spectra.
We also carried out spectral analysis of wave data measured at several wave observation stations around Japan and investigated occurrence characteristics of long waves. As a result, it was found to be difficult to apply the existing standard formula under the condition that long period waves are dominant, suggesting that further study is necessary.

Free Research Field

水工学