{"created":"2023-06-20T15:05:19.479330+00:00","id":34622,"links":{},"metadata":{"_buckets":{"deposit":"5b1f8da9-bf19-4156-b052-cf20a08be5ce"},"_deposit":{"created_by":1,"id":"34622","owners":[1],"pid":{"revision_id":0,"type":"depid","value":"34622"},"status":"published"},"_oai":{"id":"oai:jaxa.repo.nii.ac.jp:00034622","sets":["1887:1890","1896:1898:1899:1901"]},"author_link":["419967","419973","419970","419969","419974","419972","419971","419968"],"item_9_alternative_title_1":{"attribute_name":"その他のタイトル","attribute_value_mlt":[{"subitem_alternative_title":"孤立した粗さによる境界層の遷移"}]},"item_9_biblio_info_10":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"1962-11","bibliographicIssueDateType":"Issued"},"bibliographicIssueNumber":"7","bibliographicPageEnd":"143","bibliographicPageStart":"129","bibliographicVolumeNumber":"28","bibliographic_titles":[{"bibliographic_title":"東京大學航空研究所報告"},{"bibliographic_title":"Report/Aeronautical Research Institute, University of Tokyo","bibliographic_titleLang":"en"}]}]},"item_9_description_16":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"この報告は, 圧力勾配のない平板に沿う層流境界層において, 孤立した粗さにもとずく乱流への遷移の, 熱線風速計による測定の結果をまとめたものである。遷移は楔形の領域でおこるが, 楔の頂点は, 流れの速度または粗さの高さの僅かの増加によって急激に前進し, ついに粗さの位置にまで到達する。この乱流の楔が, ちょうど粗さの位置から始まるようになるのは, '粗さレイノルズ数'R_k(粗さの高さおよび粗さの高さでの層流境界層の速度に関するレイノルズ数)がある臨界値を超えるときである。R_kの臨界値は, '遷移レイノルズ数'R_t(外側の流れの速度および平板前縁から粗さまでの距離に関するレイノルズ数)の増加とともに僅かに減少する。粗さのうしろの境界層内の平均速度の横幅方向の分布は, Gregory と Walker によって始めて観察された, 流れの方向に軸をもつ渦の存在を示している。粗さのすぐうしろの部分を除いて, 平均速度の分布に主要な影響を与えるものは, 粗さの前面にまきつく馬蹄形の渦であって, 粗さの中心線上に速度分布の峰を生じ, さらにその外側に, それぞれ谷と第二の峰を生ずる。平均速度の場がこのように三次元的に変形することは, 遷移点の前進が臨界的におこることに説明を与えるものと考えられる。細いリボンを振動させて, 二次元的な攪乱を統制的に発生させると, その下流への発達は, 中央の峰の断面, 谷の断面, および外側の峰の断面において, それぞれ特徴的な過程をたどることがわかる。特に外側の峰の断面では、攪乱の増幅が極めて著しく, ついに下流の部分で, 最初に層流の破壊を生ずるようになる。この破壊は, この断面から乱流の楔の始まることを示すものにほかならない。","subitem_description_type":"Abstract"}]},"item_9_description_17":{"attribute_name":"抄録（英）","attribute_value_mlt":[{"subitem_description":"Results of hot-wire measurements are presented on transition in laminar boundary layer along a flat plate with zero pressure gradient in the presence of an isolated roughness element. Transition occurs in the region of a wedge whose vertex moves rapidly forward with slightest increase in stream velocity or roughness height until finally it reaches the roughness element. The critical condition that just causes a wedge of turbulence to originate from roughness is governed by a critical value of the roughness Reynolds number R_k, which is based on the roughness height and the velocity in the laminar boundary layer at the height of roughness. The critical value of R_k is a slowly decreasing function ot the transition Reynolds number R_t, based on the free-stream vilocity and the distance from leading edge to roughness location. The spanwise distribution of mean velocity in the boundary layer behind a roughness element for subcritical values of R_k is indicative of the presence of streamwise vortices as first observed by Gregory and Walker, Except for the station close behind roughness. a horseshoe-shaped vortex wrapped round the front of roughness gives a predominant effect on mean velocity distribution, producing a primary peak behind the centerline of roughness, and a valley and a secondary peak outside. This three-dimensional deformation of mean velocity fiedl is considered to account for the critical behavior of transition movement. Controlled two-dimensional disturbances created by a vibrating ribbon develop downstream in a way respectively characteristic of the central peak section, valley sectoin and outside peak section. The disturbances are most strongly amplified in the outside peak section, until breakdown of laminar flow takes place at a downstream station. This breakdown corresponds to the beginning of a turbulent wedge at that station.","subitem_description_type":"Other"}]},"item_9_description_32":{"attribute_name":"資料番号","attribute_value_mlt":[{"subitem_description":"資料番号: SA2404899000","subitem_description_type":"Other"}]},"item_9_publisher_8":{"attribute_name":"出版者","attribute_value_mlt":[{"subitem_publisher":"東京大学航空研究所"}]},"item_9_publisher_9":{"attribute_name":"出版者（英）","attribute_value_mlt":[{"subitem_publisher":"Aeronautical Research Institute, University of Tokyo"}]},"item_9_source_id_21":{"attribute_name":"ISSN","attribute_value_mlt":[{"subitem_source_identifier":"0376-1061","subitem_source_identifier_type":"ISSN"}]},"item_9_source_id_24":{"attribute_name":"書誌レコードID","attribute_value_mlt":[{"subitem_source_identifier":"AA00514444","subitem_source_identifier_type":"NCID"}]},"item_9_text_7":{"attribute_name":"著者所属（英）","attribute_value_mlt":[{"subitem_text_language":"en","subitem_text_value":"Department ofMechanical Engineering,  Nihon University"},{"subitem_text_language":"en","subitem_text_value":"Department ofMechanical Engineering,  Nihon University"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"谷, 一郎"}],"nameIdentifiers":[{}]},{"creatorNames":[{"creatorName":"菰田, 廣之"}],"nameIdentifiers":[{}]},{"creatorNames":[{"creatorName":"小松, 安雄"}],"nameIdentifiers":[{}]},{"creatorNames":[{"creatorName":"井内, 松三郎"}],"nameIdentifiers":[{}]},{"creatorNames":[{"creatorName":"TANI, Itiro","creatorNameLang":"en"}],"nameIdentifiers":[{}]},{"creatorNames":[{"creatorName":"KOMODA, Hiroyuki","creatorNameLang":"en"}],"nameIdentifiers":[{}]},{"creatorNames":[{"creatorName":"KOMATSU, Yasuo","creatorNameLang":"en"}],"nameIdentifiers":[{}]},{"creatorNames":[{"creatorName":"IUCHI, Matsusaburo","creatorNameLang":"en"}],"nameIdentifiers":[{}]}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2020-01-24"}],"displaytype":"detail","filename":"SA2404899.pdf","filesize":[{"value":"917.4 kB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"SA2404899.pdf","url":"https://jaxa.repo.nii.ac.jp/record/34622/files/SA2404899.pdf"},"version_id":"270d0cd0-107b-4441-97dd-95b155236782"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"eng"}]},"item_resource_type":{"attribute_name":"資源タイプ","attribute_value_mlt":[{"resourcetype":"departmental bulletin paper","resourceuri":"http://purl.org/coar/resource_type/c_6501"}]},"item_title":"Boundary-Layer Transition by Isolated Roughness","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"Boundary-Layer Transition by Isolated Roughness","subitem_title_language":"en"}]},"item_type_id":"9","owner":"1","path":["1890","1901"],"pubdate":{"attribute_name":"公開日","attribute_value":"2015-03-26"},"publish_date":"2015-03-26","publish_status":"0","recid":"34622","relation_version_is_last":true,"title":["Boundary-Layer Transition by Isolated Roughness"],"weko_creator_id":"1","weko_shared_id":-1},"updated":"2023-06-20T23:38:23.259480+00:00"}