{"title":"FUNDAMENTAL STUDIES ON THE THREE DIMENSIONAL STRUCTURE OF LANGMUIR CIRCULATION","authors":"Yukihiro Akiya, M. Sanjou, I. Nezu","doi":"10.2208/JSCEJB.66.371","DOIUrl":"https://doi.org/10.2208/JSCEJB.66.371","url":null,"abstract":"ラングミュアー循環流を対象とした室内実験や海洋観測のほとんどが,水表面のストリーク構造からその存在を推測しており,直接的にラングミュアー循環流の横断面構造を捉えたものは一部の研究を除きほとんどない.本研究では,高速度カメラを風洞水槽の水中部に設置してPIVによって循環流の多点同時計測に成功した.実験結果より系統的にアスペクト比および風速を変えることにより,流れの3次元構造の変化や2次渦の発生個数の増減特性を明らかにした.特にアスペクト比が4の場合には風速の増加によって2次渦の個数が減少し,また一定風速の下ではアスペクト比の減少に伴い個数が増加する興味深い結果が得られた.さらに位相解析を行い,波の谷では循環流が鉛直方向に縮められ,波の峰では引き伸ばされる特性が解明された.","PeriodicalId":11343,"journal":{"name":"Doboku Gakkai Ronbunshuu B","volume":"56 1","pages":"371-383"},"PeriodicalIF":0.0,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85421214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"ON THE RESONANCE CHARACTERISTICS OF THE FLOAT TYPE WAVE POWER CONVERSION DEVICE","authors":"K. Taneura, K. Hadano, H. Yoneyama, K. Ikegami, Kimihiko Nakano, P. Koirala","doi":"10.2208/JSCEJB.66.196","DOIUrl":"https://doi.org/10.2208/JSCEJB.66.196","url":null,"abstract":"本研究では,ワイヤ,フロート,カウンタウェイトなどを組合わせた可動物体型波力発電装置の共振特性の検討を行っている.共振解析モデルでは時々刻々のフロート変位と水面変位の相対座標を用いている.フロートの運動方程式では,フロート・流体間の相互作用力を,波強制力,付加質量,造波減衰により評価しており,これと回転体の力学と発電機関連の力学を組み合わせて方程式系を構成している.共振特性解析は,波の作用下で稼動状態にあるフロートの上下動の振幅を,波の振幅と比較することにより検討している.さらに発生電力,トルクやワイヤ張力などの物理量の波周期による変化を評価している.また,装置が安全に稼働しかつ発生電力が大きい条件を探るため,フロートが一部没水を維持できる条件下で発生電力を大きくする装置諸元を調べている.","PeriodicalId":11343,"journal":{"name":"Doboku Gakkai Ronbunshuu B","volume":"13 1","pages":"196-206"},"PeriodicalIF":0.0,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74936544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"COEFFICIENTS OF FLOAT IN ACTUAL RIVERS UNDER FLOODING CONDITIONS","authors":"Y. Nihei, Takehiro Sakai","doi":"10.2208/JSCEJB.66.104","DOIUrl":"https://doi.org/10.2208/JSCEJB.66.104","url":null,"abstract":"","PeriodicalId":11343,"journal":{"name":"Doboku Gakkai Ronbunshuu B","volume":"47 1","pages":"104-118"},"PeriodicalIF":0.0,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74324772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"MECHANISM OF VEGETATION DESTRUCTION DUE TO A FLOOD FLOW AND APPLICATION TO VEGETATION MANAGEMENTS IN A COMPOUND MEANDERING RIVER","authors":"T. Gotoh, S. Fukuoka, Shinya Nigo, Jun Nakasuka","doi":"10.2208/JSCEJB.66.47","DOIUrl":"https://doi.org/10.2208/JSCEJB.66.47","url":null,"abstract":"複断面蛇行河川では大洪水時の水位ピーク時に主流が内岸寄りを走り,内岸砂州が洗掘を受けるため内岸砂州上の樹木群の倒伏・流失が想定される.太田川では,河道内樹木の管理を目的とした樹木調査を行い,洪水時の水面形の時間変化を観測する準備を行ってきた.平成17年9月には,計画高水流量相当の洪水が発生し,内岸砂州上の樹木群が倒伏・流失した.本研究では,観測水面形の時間変化を用いた非定常二次元洪水流・河床変動解析により,洪水中の流れと河床変動,樹木倒伏の関係について検討した.そして,流体力と河床洗掘の観点から,砂州河床上の樹木倒伏・破壊の主な要因は河床洗掘であることを明らかにした.最後に,本調査・研究から明らかにされた樹木管理の教訓とその活用を示している.","PeriodicalId":11343,"journal":{"name":"Doboku Gakkai Ronbunshuu B","volume":"45 1","pages":"47-65"},"PeriodicalIF":0.0,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76246128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"STUDY ON ECOLOGICAL ENVIRONMENT OF TIDAL FLAT IN THE OTA RIVER FLOODWAY","authors":"S. Nakashita, T. Hibino, K. Komai, S. Fukuoka, Toru Abe","doi":"10.2208/JSCEJB.66.344","DOIUrl":"https://doi.org/10.2208/JSCEJB.66.344","url":null,"abstract":"太田川放水路に形成されている干潟の特性を明らかにするために,1996年から2008年にかけて底質,水質の経年変動,生物分布および有機泥の捕捉調査を行った.さらに,生態環境の形成に果たす河川構造物の役割について検討するために,生物分布,底質,地下水質,地下水位調査を行った.調査結果より,二枚貝の棲息には地盤内の間隙の保持等,地下水流動によって起こる二次現象が重要であることを明らかにした.また,護岸前後に形成された水位差によって促進される地下水流動が地盤内の間隙への有機泥の堆積抑制等に寄与していることを明らかにし,地下水環境を考慮した河川構造物の構築により安定した多様な生態環境が形成されることを示した.","PeriodicalId":11343,"journal":{"name":"Doboku Gakkai Ronbunshuu B","volume":"31 1","pages":"344-358"},"PeriodicalIF":0.0,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91272987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"NUMERICAL SIMULATION FOR SEDIMENTATION PROCESS OF BLOCKS BY SOLID-LIQUID TURBULENCE MODEL","authors":"E. Harada, H. Gotoh, N. Tsuruta","doi":"10.2208/JSCEJB.66.25","DOIUrl":"https://doi.org/10.2208/JSCEJB.66.25","url":null,"abstract":"","PeriodicalId":11343,"journal":{"name":"Doboku Gakkai Ronbunshuu B","volume":"86 1","pages":"25-34"},"PeriodicalIF":0.0,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87428182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"ONE-DIMENSIONAL NUMERICAL MODEL FOR CYCLIC SEAWARD BAR MIGRATIONS","authors":"Y. Kuriyama","doi":"10.2208/JSCEJB.66.302","DOIUrl":"https://doi.org/10.2208/JSCEJB.66.302","url":null,"abstract":"","PeriodicalId":11343,"journal":{"name":"Doboku Gakkai Ronbunshuu B","volume":"79 1","pages":"302-320"},"PeriodicalIF":0.0,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73331097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"NUMERICAL SIMULATION OF DEFORMATION PROCESS OF ARMOR BLOCKS BY DEM-MPS COUPLING MODEL","authors":"H. Gotoh, E. Harada, H. Ikari, K. Ooe, Tsunehito Yasuoka","doi":"10.2208/JSCEJB.66.258","DOIUrl":"https://doi.org/10.2208/JSCEJB.66.258","url":null,"abstract":"防波堤の被覆ブロックの被災メカニズムを解明し,被災防止のための解決策を検討することは海岸構造物の維持管理コスト削減のためには重要である.本稿では,造波水路を用いた水理実験およびMPS法とDEMの融合による数値シミュレーションの双方から,マウンド法先部に設置した被覆ブロック群の崩壊過程を検討し,被覆ブロック群崩壊のメカニズムの一端を明らかにすることを目的とする.具体的には,水理実験から観察される被覆ブロック群が崩壊に至る一連のプロセスから崩壊の因子を抽出し,その因子をパラメータとした数値シミュレーションを実施して,予測された因子の妥当性を裏付けた.","PeriodicalId":11343,"journal":{"name":"Doboku Gakkai Ronbunshuu B","volume":"58 1","pages":"258-267"},"PeriodicalIF":0.0,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91001263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}