1993 Fiscal Year Final Research Report Summary
Characterixtics of wave breaking over bottom boundary with arbitrary shape and a unified analysis on them
| Project/Area Number |
04452233
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Hydraulic engineering
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| Research Institution | Gifu University |
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Principal Investigator |
YASUDA Takashi Gifu Univ., Dept. of Civil Eng., Prof., 工学部, 教授 (10093329)
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| Co-Investigator(Kenkyū-buntansha) |
SAKAKIBARA Yukio Toyota Tech. College, Dept. of Civil Eng., Re. Assoc., 助手 (50249801)
SHINODA Seirou ditto, Re. Assoc, 工学部, 助手 (80187369)
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| Project Period (FY) |
1992 – 1993
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| Keywords | Wave breaking / Breaker index / Breaker height / Breaker type / Solitary wave / Submerged dike / Boundary Integral Method / BIM |
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| Research Abstract |
1. Unified formulation for breaker index of solitary waves over uneven bottmos.
Breaking wave characteristics were made quantitatively clear for a solitary wave incident to a uniformly sloping bottom, a submerged step and a submerged dike, resperdirely. Breaker indices were defined for the following three items and further their geverning laws were extablished ; i) Critical incident wave height H_c which gives the limiting wave height of the incident wave passing through a step or dike without breaking, ii) Breaking point and iii) Breaker height.
2. Breaking of a solitary wave caused by a submerged dike and its internal kinematic.
Experiments and BIM simulations on the propagation up to breaking of a solitary wave over a submerged dike verifield that the numerical modeluse for the BIM simulations can give sufficiently accurate solutions which agree very well with the experimental results concerning on not only the water surface elevation but the also internal kimematics. The computation m
… More
ade clear that the vertical distributions of horizontal and vertical water particle velocites remarkably change dependently on the breaker type, that is, either spiller or plunger.
3. Internal kinematics of a solitary wave accompanying a plunging jet from its crest and their extreme values.
Internal kinematics of a solitary wave after breaking limit and their relationships to breaker-type were made clear by performing BIM simulations. Formulations were made for the relation between their extreme values and breaker type.
Impulsive pressure due to a solitary wave breaking exerted on a vertical wall and its relation to breaker type.
It was found that impulsive pressure exerted on a vertical wall is closely related to breaker type through entrained air due to breaking.
5. Wave deformation and after breaking on a step and its relation to breaker type.
Formation were made for the relations of the solitaly wave attenuation after breaking to the breaker type index. It was found that the wave heigh can be reduced to about 20% of its initial height by causing plunning breaker over a step and wave due to breaking is useful for wave control. Less
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