{"created":"2023-06-20T14:36:04.849256+00:00","id":2382,"links":{},"metadata":{"_buckets":{"deposit":"9921c3c6-1662-4075-95f0-2b9fdf4e7a93"},"_deposit":{"created_by":1,"id":"2382","owners":[1],"pid":{"revision_id":0,"type":"depid","value":"2382"},"status":"published"},"_oai":{"id":"oai:jaxa.repo.nii.ac.jp:00002382","sets":["1887:1893","9:10:309:353"]},"author_link":["5892","5895","5894","5893","5897","5898","5899","5896"],"item_3_alternative_title_1":{"attribute_name":"その他のタイトル","attribute_value_mlt":[{"subitem_alternative_title":"回転翼のブレード／渦干渉騒音"},{"subitem_alternative_title":"ヘリコプタロータの翼端噴射に関する数値解析"}]},"item_3_alternative_title_2":{"attribute_name":"その他のタイトル（英）","attribute_value_mlt":[{"subitem_alternative_title":"Blade vortex interaction noise of rotary wing"}]},"item_3_biblio_info_10":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"2005-01-31","bibliographicIssueDateType":"Issued"},"bibliographicVolumeNumber":"JAXA-RR-04-014E","bibliographic_titles":[{"bibliographic_title":"宇宙航空研究開発機構研究開発報告"},{"bibliographic_title":"JAXA Research and Development Report","bibliographic_titleLang":"en"}]}]},"item_3_description_16":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"ブレード／渦干渉(Blade-Vortex Interaction: BVI)騒音は、先行するメイン・ロータのブレードが吐き出した翼端渦が後続ブレードの翼端付近を通過する時に起こる弱い干渉、あるいは先行ブレードの翼端渦を後続ブレードが切る時に起こる強い干渉によって、ブレードの空力荷重が急激に変動することから発生する。この騒音は、特に前進方向の下方に指向性を持ち、主にヘリコプタが着陸する際に発生するため、付近の住民に与える影響が大きく、都市部におけるヘリポート設置の妨げとなっている。BVI騒音の低減法としては、翼型や翼端形状を工夫する受動的なものから、高調波制御、アクティブ・フラップ、翼端噴射などの能動的なものまで、様々な方法が提案されている。航空宇宙技術研究所(NAL)と韓国の浦項工科大学校(POSTECH)は、能動的なBVI騒音低減法の中で、特に翼端噴射に着目して、その低減効果をCFDで解析することを目的に、共同研究を行った。この翼端噴射とは、ヘリコプタ・ブレードの翼端から半径方向外向きにジェットを噴き出すことで、翼端渦の位置や構造を変化(渦の循環を弱めたりコア半径を大きくする)させ、BVI騒音を低減しようとする技術である。本研究では、まず、単一格子を用いて固定ブレードの翼端噴射が翼端渦の挙動に及ぼす影響をEuler/Navier-Stokesコードで解析した。続いて、移動重合格子法を用いた3次元非定常EulerコードとFfowcs Williams and Hawkings(FW-H)の式に基づく空力音響コードを組み合わせた計算法によって、回転場での翼端噴射の騒音低減効果を解析した。本報告は、後者の回転場での解析結果について述べるものである。ここで用いた方法が、実験値との比較を通して、BVI騒音の特徴であるピーキーな音圧波形をよく予測することが示されたので、翼端噴射のBVI騒音低減効果を解析する方法として適切であることが確認された。移動重合格子法の計算に用いた格子は3種類(ブレード格子、内側背景格子、外側背景格子)である。ブレード格子は、ブレード1本の周りを覆い、ブレードと共に回転運動を行う物体適合格子であり、背景格子はブレードから放出された翼端渦を捉えるための直交格子である。ここでも、固定ブレードの計算で検討した翼端噴射速度、噴射方向、噴射ロ面積をパラメトリックに変化させて翼端渦の挙動に及ぼす影響を解析した。結果として、翼端噴射では、噴射方向が騒音に及ぼす影響は小さく、噴射量と噴射速度を大きくすることが騒音低減に有効であり、最大2.55dBの低減効果が確認できた。","subitem_description_type":"Abstract"}]},"item_3_description_17":{"attribute_name":"抄録（英）","attribute_value_mlt":[{"subitem_description":"Blade vortex interaction (BVI) noise, which is generated by impulsive change in the pressure over the interacting blade preceding the pressure jump, propagates sound to far field observers. In general, these interactions occur in forward-descent flight conditions, especially during a landing approach. The acoustic signal from BVI is generally in the frequency range to which the human subjective response is most sensitive. In order to reduce BVI noise, many researchers have been studying not only passive remedies such as rotor tip design and leading edge modification, but also active devices such as the higher harmonic control method, active tab, active flap, and tip-jet blowing. The National Aerospace Laboratory (NAL) in Japan and Pohang University of Science and Technology (POSTECH) in Korea have conducted a collaborative research program on the effects of lateral wing-tip blowing to reduce BVI noise from helicopter rotors. The lateral wing-tip method is one of the active control methods to control the generation and behavior of tip vortical flow by blowing a jet flow at the tip of the main rotor. In the first stage of the research, three-dimensional compressible Euler/Navier-Stokes equations are solved to calculate the effect of blowing air from the blade tip on the tip vortex of a fixed single blade. In the next stage, predictions of BVI noise will be made by combining an unsteady Euler code with an aeroacoustic code based on the Ffowcs-Williams and Hawkings formulation. In the present report, predictions of BVI noise are performed for a two-blade rotor. A moving overlapped grid system with three types of grids including blade, inner and outer background grids is used to simulate the BVI of a helicopter with two blades in forward/descending flight. The body-fitted blade grid moves with the blade motion, and the background grids in this Cartesian system are placed around the rotor disk in order to include the trace of the tip vortex. The effects of lateral blowing in the tip region to reduce BVI noise are examined using various jet blowing conditions including jet speed, jet slit area and injection direction, which are also used in the fixed rotor calculations. Calculations show that the reductions in BVI noise peak and the sound pressure level are more dependent on the jet velocity and flow rate than on jet directions, and the maximum decrease in BVI noise is 2.55 dB.","subitem_description_type":"Other"}]},"item_3_description_32":{"attribute_name":"資料番号","attribute_value_mlt":[{"subitem_description":"資料番号: AA0048449000","subitem_description_type":"Other"}]},"item_3_description_33":{"attribute_name":"レポート番号","attribute_value_mlt":[{"subitem_description":"レポート番号: JAXA-RR-04-014E","subitem_description_type":"Other"}]},"item_3_publisher_8":{"attribute_name":"出版者","attribute_value_mlt":[{"subitem_publisher":"宇宙航空研究開発機構"}]},"item_3_publisher_9":{"attribute_name":"出版者（英）","attribute_value_mlt":[{"subitem_publisher":"Japan Aerospace Exploration Agency (JAXA)"}]},"item_3_source_id_21":{"attribute_name":"ISSN","attribute_value_mlt":[{"subitem_source_identifier":"1349-1113","subitem_source_identifier_type":"ISSN"}]},"item_3_source_id_24":{"attribute_name":"書誌レコードID","attribute_value_mlt":[{"subitem_source_identifier":"AA1192675X","subitem_source_identifier_type":"NCID"}]},"item_3_text_6":{"attribute_name":"著者所属","attribute_value_mlt":[{"subitem_text_value":"宇宙航空研究開発機構"},{"subitem_text_value":"宇宙航空研究開発機構"},{"subitem_text_value":"宇宙航空研究開発機構"},{"subitem_text_value":"Pohang Univ. of Science and Technology"}]},"item_3_text_7":{"attribute_name":"著者所属（英）","attribute_value_mlt":[{"subitem_text_language":"en","subitem_text_value":"Japan Aerospace Exploration Agency"},{"subitem_text_language":"en","subitem_text_value":"Japan Aerospace Exploration Agency"},{"subitem_text_language":"en","subitem_text_value":"Japan Aerospace Exploration Agency"},{"subitem_text_language":"en","subitem_text_value":"Pohang University of Science and Technology"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"Yang, Choongmo"}],"nameIdentifiers":[{}]},{"creatorNames":[{"creatorName":"青山, 剛史"}],"nameIdentifiers":[{}]},{"creatorNames":[{"creatorName":"齊藤, 茂"}],"nameIdentifiers":[{}]},{"creatorNames":[{"creatorName":"Baek, Jehyun"}],"nameIdentifiers":[{}]},{"creatorNames":[{"creatorName":"Yang, Choongmo","creatorNameLang":"en"}],"nameIdentifiers":[{}]},{"creatorNames":[{"creatorName":"Aoyama, Takashi","creatorNameLang":"en"}],"nameIdentifiers":[{}]},{"creatorNames":[{"creatorName":"Saito, Shigeru","creatorNameLang":"en"}],"nameIdentifiers":[{}]},{"creatorNames":[{"creatorName":"Baek, Jehyun","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":"2020-01-15"}],"displaytype":"detail","filename":"48449000.pdf","filesize":[{"value":"5.1 MB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"48449000.pdf","url":"https://jaxa.repo.nii.ac.jp/record/2382/files/48449000.pdf"},"version_id":"fe347dac-1cc3-4ec3-9247-3560b1d9ed92"}]},"item_keyword":{"attribute_name":"キーワード","attribute_value_mlt":[{"subitem_subject":"ブレード／渦干渉","subitem_subject_scheme":"Other"},{"subitem_subject":"オイラーの運動方程式","subitem_subject_scheme":"Other"},{"subitem_subject":"ヘリコプタ","subitem_subject_scheme":"Other"},{"subitem_subject":"ロータブレード","subitem_subject_scheme":"Other"},{"subitem_subject":"航空音響学","subitem_subject_scheme":"Other"},{"subitem_subject":"数値解析","subitem_subject_scheme":"Other"},{"subitem_subject":"Ffowcs-Williams and Hawkings方程式","subitem_subject_scheme":"Other"},{"subitem_subject":"翼端渦","subitem_subject_scheme":"Other"},{"subitem_subject":"移動重合格子法","subitem_subject_scheme":"Other"},{"subitem_subject":"補間アルゴリズム","subitem_subject_scheme":"Other"},{"subitem_subject":"ベクトル演算","subitem_subject_scheme":"Other"},{"subitem_subject":"騒音予測","subitem_subject_scheme":"Other"},{"subitem_subject":"blade-vortex interaction","subitem_subject_language":"en","subitem_subject_scheme":"Other"},{"subitem_subject":"Euler equation of motion","subitem_subject_language":"en","subitem_subject_scheme":"Other"},{"subitem_subject":"helicopter","subitem_subject_language":"en","subitem_subject_scheme":"Other"},{"subitem_subject":"rotor blade","subitem_subject_language":"en","subitem_subject_scheme":"Other"},{"subitem_subject":"aeroacoustics","subitem_subject_language":"en","subitem_subject_scheme":"Other"},{"subitem_subject":"numerical analysis","subitem_subject_language":"en","subitem_subject_scheme":"Other"},{"subitem_subject":"Ffowcs-Williams and Hawkings formulation","subitem_subject_language":"en","subitem_subject_scheme":"Other"},{"subitem_subject":"tip vortex","subitem_subject_language":"en","subitem_subject_scheme":"Other"},{"subitem_subject":"moving overlapped grid system","subitem_subject_language":"en","subitem_subject_scheme":"Other"},{"subitem_subject":"interpolation algorithm","subitem_subject_language":"en","subitem_subject_scheme":"Other"},{"subitem_subject":"vector computation","subitem_subject_language":"en","subitem_subject_scheme":"Other"},{"subitem_subject":"noise prediction","subitem_subject_language":"en","subitem_subject_scheme":"Other"}]},"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":"technical report","resourceuri":"http://purl.org/coar/resource_type/c_18gh"}]},"item_title":"Numerical study on the lateral jet flow of helicopter rotor","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"Numerical study on the lateral jet flow of helicopter rotor","subitem_title_language":"en"}]},"item_type_id":"3","owner":"1","path":["353","1893"],"pubdate":{"attribute_name":"公開日","attribute_value":"2015-03-26"},"publish_date":"2015-03-26","publish_status":"0","recid":"2382","relation_version_is_last":true,"title":["Numerical study on the lateral jet flow of helicopter rotor"],"weko_creator_id":"1","weko_shared_id":-1},"updated":"2023-06-21T09:23:33.896770+00:00"}