Experimental Studies on the Characteristics of Near-bottom Flow in the Current with Waves
| Project/Area Number |
06452372
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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 |
Irrigation, drainage and rural engineering/Rural planning
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| Research Institution | Saga University |
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Principal Investigator |
SEGUCHI Masahiro Saga University, Faculty of Agriculture, Professor, 農学部, 教授 (20093974)
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| Co-Investigator(Kenkyū-buntansha) |
KATO Osamu Saga University, Faculty of Agriculture, Professor, 農学部, 教授 (40038295)
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| Project Period (FY) |
1994 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥5,800,000 (Direct Cost: ¥5,800,000)
Fiscal Year 1996: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1995: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1994: ¥2,500,000 (Direct Cost: ¥2,500,000)
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| Keywords | current with waves / wave boundary layr / wave flow component / eddy viscosity / bottom shear stress / bottom sediment / resuspension rate / 順流 / 逆流 / レィノルズ応力 / 運動輸送量 / 底面境界層 / 流速分布 / 共存場 / 時間平均流速 / アンサンブル平均流速 / ストークス波 / エネルギースペクトル |
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| Research Abstract |
The Summary of this research results is as follows :
(1) The steady flow component in the current with waves was theoretically analyzed by using a three-layr eddy viscosity model near the bottom boundary layr. Moreover, a simple method to estimate the important parameters contained in the analytical solution was presented. The analytical solutions almost agreed with the experimental results.
(2) The theoretical solution of the wave flow component in the current with waves was obtained by using a two-layr eddy viscosity model, in which the eddy viscosity in the wave boundary layr increased quadratically with the height above the bottom and that outside the wave boundary layr constant. The theoretical and experimental values almost agreed.
(3) The analytical values of shear stress in the current with waves were obtained from the theoretical solutions of the steady and wave flow components. The variations of the bottom shear stress with wave phase and the influences of wave motion on the bottom shear stress were clarified from the analytical results of shear stress.
(4) The phase difference of the wave flow component in the current with waves inside and outside the wave boundary layr was maximum at the bottom. The maximum value of phase difference ranged between 40ﾟ and 48ﾟ for the present experimental conditions.
(5) The resuspension rate of the bottom sediment in the current with waves for the present experimental conditions was about 20% to 30% bigger than that in the current. The variations of the resuspension rate of the bottom sediment with the wave height under a constant velocity were bigger than those with the magnitude of velocity under a constant wave height.
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Report
(4 results)
Research Products
(1 results)
