2002 Fiscal Year Final Research Report Summary
LABORATORY AND FIELD EXPERIMENTS AND DEVELOPMENT OF NUMERICAL NUMERICAL MODEL FOR 3-D FLUID MOTION AND SEDIMENT MOVEMENT DUE TO WAVE BREAKING
| Project/Area Number |
13450203
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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 | TOKYO UNIVERSITY OF FISHERIES |
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Principal Investigator |
OKAYASU Akio TOKYO UNIVERSITY OF FISHERIES, FACULTY OF FISHERIES, ASSOCIATE PROFESSOR, 水産学部, 助教授 (20213994)
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| Co-Investigator(Kenkyū-buntansha) |
MORI Nobuhito CENTRAL RESEARCH INSTITUE OF ELECTRIC POWER INDUSTRY, SENIOR RESEARCHER, 水理部, 主任研究員
SHIBAYAMA Tomoya YOKOHAMA NATIONAL UNIVERSITY, GRADUATE SCHOOL OF ENGINEERING, PROFESSOR, 工学研究院, 教授 (40143391)
KANEHIRO Haruyuki TOKYO UNIVERSITY OF FISHERIES, FACULTY OF FISHERIES, PROFESSOR, 水産学部, 教授 (80134857)
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| Project Period (FY) |
2001 – 2002
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| Keywords | WAVE BREAKING / OBULIOUERY DESCENDING EDDY / 3-D FULID MOTION / SEDIMENT MOVEMENT / FIELD MEASUREMENT / LARUGE WAVE FULME / NUMERICAL MODEL |
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| Research Abstract |
TWO-DIMENSIONAL SUSPENDED SEDIMENT DISTRIBUTION CAUSED BY WAVE BREAKING ON A SLOPE WAS MEASURED IN A LABORATORY WAVE FLUME BY USING A CT TYPE SEDIMENT METER. THE 2-DIMENSIONAL SEDIMENT CONCENTRATION WAS OBTAINED FROM ATTENUATION RATE OF TRANSMITTED LASER POWER. IT WAS CONFIRMED THAT CONCENTRARION CAN BE QUANTITATIVELY EVALUATED. SIZE AND MOVEMENT OF SUSPENDED SEDIMENT CLOUDS WERE INVESTIGATED.
THREE-DIMENSIONAL FLUID MOTION CAUSED BY WAVE BREAKING WAS MEASURED IN A LARGE WAVE FLUME BY USING AN ARRAY OF ACOUSTIC DOPPELAR VELOCIMETERS. VELOCITY VECTORS AND VORTICITY WERE CALCULATED FROM MEASURED DATA. TURBULENCE BY LOCAL EDDIES AND TURBULENCE PROPERTIES WERE INVESTIGATED. IT WAS FOUND THAT STRENGTH OF HORIZONTAL VORTICES INCREASE, THEN DECREASE WITH BREAKING WAVE PROPAGATION AND VERTICAL VORTICES ARE RELATIVELY WEAK NEAR THE BREAKING POINTS. VORTICITY BECOMES HOMOGENIOUS IN THE INNER SURF ZONE.
IN ORDER TO EVALUATE INTERMITTENCY AND THREE-DIMENSIONALITY OF ORGANIZED EDDIES IN THE SURF ZONE, FIELD EXPERIMENTS WERE CONDUCTED WITH AN OBSERVATION ARRAY OF VELOCIMETERS AND SEDIMENT METERS. IT WAS FOUND THAT VELOCITY ACCERELATION AND TURBULENCE SHOW HIGH CORRELALTION AND CORRELATION BETWEEN THESE PROPERTIES AND SEDIMENT CONCENTRAION IS ALSO HIGH. INTERMITTENCY OF SEDIMENT PICKUP BY WAVE BREAKING WAS SHOWN AND THE PICKUP EVENTS COULD BE DETECTED BY FLUID VELOCITY AND ACCERELATION.
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