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1. Boundary-Layer Transition Control by Plasma Crossflow Reduction in Swept Wing

Author

Miwa, Yuto, Yoshimi, Ikuya, Matsuno, Takashi, Kwak, Dongyoun, Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Rüdiger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Hirche, Sandra, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Li, Yong, Series Editor, Liang, Qilian, Series Editor, Martín, Ferran, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Möller, Sebastian, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Oneto, Luca, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Speidel, Joachim, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zamboni, Walter, Series Editor, Zhang, Junjie James, Series Editor, Lee, Sangchul, editor, Han, Cheolheui, editor, Choi, Jeong-Yeol, editor, Kim, Seungkeun, editor, and Kim, Jeong Ho, editor

Published
2023
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2. Parametric Studies of the Fuselage Geometry of a Double-Bubble Aircraft Configuration

Author

Takahashi, Kenya, Furuya, Ryutaro, Nomura, Toshiyuki, Kwak, Dongyoun, Fukiba, Katsuyoshi, Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Rüdiger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Hirche, Sandra, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Li, Yong, Series Editor, Liang, Qilian, Series Editor, Martín, Ferran, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Möller, Sebastian, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Oneto, Luca, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Speidel, Joachim, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zamboni, Walter, Series Editor, Zhang, Junjie James, Series Editor, Lee, Sangchul, editor, Han, Cheolheui, editor, Choi, Jeong-Yeol, editor, Kim, Seungkeun, editor, and Kim, Jeong Ho, editor

Published
2023
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7. NEXST-DB(Database) Report

Author

Yoshida, Kenji, Kwak, Dongyoun, and Tokugawa, Naoko

Subjects
NEXST-1 project, Supersonic transport, flight test, wind tunnel test, CFD
Abstract

NEXST-1プロジェクトは, 1997年から2005年にかけて実施した小型超音速実験機プロジェクトで, 次世代超音速旅客機（SST）の抵抗低減に関する先進技術の飛行実証を目的として実施された. 本プロジェクトでは, 圧力抵抗低減に寄与する主翼平面形とWarp形状による揚力依存抵抗の低減効果と, 翼胴干渉を考慮したエリアルール胴体設計による体積依存造波抵抗の低減効果を確認すると同時に, 世界初となる亜音速前縁型主翼の自然層流翼設計技術による摩擦抵抗の低減効果も飛行実証された. 本飛行実験データは, 実験機の開発過程で行った風洞試験結果, 並びに飛行実験後に行った実験機形状に対するCFD解析結果との比較を通して、将来の次世代SST研究における貴重なデータと考えられるため, 我が国において広く多くの研究者の利用に供することが重要との認識から, それらをデータベース（DB）化して2008年7月より公開した. その後, 約10年の運用を経て, 現在はサーバシステム及びネットワーク環境の変更に伴いDBシステムの改修が不可能となったため公開を断念せざる得なくなった. そこで, 利用者の利便性の観点から主要なデータ（NEXST-1実験機単体に関するデータ）については資料化を通して公開する方針に変更した. 本資料はそれらをまとめたものである., JAXA developed the database (NEXST-DB) for aerodynamic design of a future supersonic transport (SST). It is based on lots of aerodynamic results of JAXA's scaled supersonic experimental airplane project (NEXST-1) which consists of principal flight test results, wind tunnel tests data, and CFD analysis results. Then, this database was exhibited for Japanese researchers by using a web system in July, 2008. After replacing the web system in 2016, unfortunately the situation that the web system does not work has been continuing because the NEXST-DB was not able to be replaced at that time. Therefore, JAXA planned to publish the main data of the NEXST-DB as a technical report in order to solve this situation., 形態: カラー図版あり, Physical characteristics: Original contains color illustrations, 資料番号: AA1930023000, レポート番号: JAXA-RM-19-010

Published
2020

10. Wind-tunnel tests for developing the low-boom design concept demonstrator (D-SEND)

Author

Makino, Yoshikazu, Noguchi, Masayoshi, and Kwak, Dongyoun

Abstract

第2回風洞技術の開発と応用シンポジウム: 風洞シンポジウム2013 (2013年10月11日. 清水建設株式会社技術研究所), 江東区, 東京, Symposium on Developments and Applications of Wind Tunnel Technologies 2nd meeting (October 11, 2013. Institute of Technology, SHIMIZU CORPORATION), Koto-ku, Tokyo, Japan, 形態: カラー図版あり, Physical characteristics: Original contains color illustrations, 資料番号: AA1530054006, レポート番号: JAXA-SP-15-021

Published
2016

11. Flight Test for Paint-Riblet

Author

Kurita, Mitsuru, primary, Iijima, Hidetoshi, additional, Koga, Seigo, additional, Nishizawa, Akira, additional, Kwak, Dongyoun, additional, Iijima, Yoshimi, additional, Takahashi, Hidemi, additional, and Abe, Hiroyuki, additional

Published
2020
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13. Investigation on Supersonic Transport Conceptual Design towards Optimized Take-off Performance

Author

Rinoie, Kenichi, Toyoda, Kosuke, and Kwak, Dongyoun

Abstract

第46回流体力学講演会/第32回航空宇宙数値シミュレーション技術シンポジウム (2014年7月3日-4日. 弘前文化センター), 弘前市, 青森県, 46th Fluid Dynamics Conference / 32nd Aerospace Numerical Simulation Symposium (July 3-4, 2014. Hirosaki Bunka Center), Hirosaki, Aomori, Japan, One of the difficult design problems of supersonic transport is to improve both the low-speed and supersonic aerodynamic performance. This paper summarizes the authors' previous researches in this subject. First, a multi-point design method for preliminary design of supersonic transports to obtain a compromised solution at low speeds and at supersonic speeds is reviewed. Second, non-linear pitching moment characteristics which are observed at relatively high angle of attack at low speeds is discussed from design and aerodynamic points of view. The wind tunnel experimental results conducted by the authors are also described. Third, a simplified this non-linear pitching moment characteristics has been investigated and is summarized here. These methods are going to be integrated into a revised conceptual design method for supersonic transports., 形態: カラー図版あり, Physical characteristics: Original contains color illustrations, 資料番号: AA1530023009, レポート番号: JAXA-SP-14-010

Published
2015

14. Flight Test of a Paint-Riblet for Reducing Skin-Friction

Author

Kurita, Mitsuru, primary, Nishizawa, Akira, additional, Kwak, Dongyoun, additional, Iijima, Hidetoshi, additional, Iijima, Yoshimi, additional, Takahashi, Hidemi, additional, Sasamori, Monami, additional, Abe, Hiroyuki, additional, Koga, Seigo, additional, and Nakakita, Kazuyuki, additional

Published
2018
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15. CFD analysis of the NEXST-1 using JAXA's code

Author

Kwak, Dongyoun, Lei, Zhong, and Ishikawa, Hiroaki

Subjects
計算格子, 境界層遷移, 空力設計, 超音速機, computational grid, NEXST-1, 計算流体力学, aeroelastic deformation, computational fluid dynamics, research aircraft, 実験機, 風洞試験, aerodynamic design, wing planform, 翼平面形, flight test, 飛行試験, 航空機設計, wind tunnel test, 空力弾性変形, supersonic aircraft, boundary layer transition, aircraft design
Abstract

SST-CFDワークショップ.次世代超音速機の数値シミュレーション利用技術に関する国際ワークショップ: Toward the Future form NEXST-1 Flight Trial 宇宙航空研究開発機構 20061012-20061013 東京 日本, SST-CFD Workshop. International Workshops on Numerical Simulation Technology for Design of Next Generation Supersonic Civil Transport: Toward the Future form NEXST-1 Flight Trial Japan Aerospace Exploration Agency 20061012-20061013 Tokyo Japan, A flight test of a supersonic experimental airplane (NEXST-1: National EXperimental Supersonic Transport-1) was conducted successfully by JAXA in October 2005. In this study some aerodynamics design concepts were verified by comparing the flight test results with CFD (Computational Fluid Dynamics) analysis using JAXA's CFD codes, a structured mesh code UPACS (Unified Platform for Aerospace Computation Simulation) and an unstructured mesh code TAS (Tohoku university Aerodynamic Simulation). After the CFD codes was verified using a wind tunnel test results, the CFD results were compared with the flight test results. The aeroelastic deformation and the boundary layer transition data of flight test were taken into account to improve CFD analysis. The effect of the design concept of the NEXST-1 was also confirmed by CFD analysis., 資料番号: AA0063609072, レポート番号: JAXA-SP-06-029E

Published
2007

21. 超音速航空機(SST)形態の低速高迎角ロール特性に関する研究

Author

Kwak, Dongyoun, Shirotake, Masashi, Noguchi, Masayoshi, Rinoie, Kenichi, Watanabe, Shigeya, 城武 雅, 野口 正芳, 李家 賢一, 渡辺 重哉, Kwak, Dongyoun, Shirotake, Masashi, Noguchi, Masayoshi, Rinoie, Kenichi, Watanabe, Shigeya, 城武 雅, 野口 正芳, 李家 賢一, and 渡辺 重哉

Abstract

Wind tunnel tests were performed to investigate rolling moment characteristics of a cranked arrow wing SST configuration at high incidence angles. Force measurements and surface static pressure measurements were conducted with the model rolled statically. In order to understand behaviors of the leading edge separation vortex, stereoscopic PIV survey was performed at x/C(sub r) = 0.55 and x/C(sub r) = 0.83. With increasing roll angles, linearly stable rolling moments were obtained at low incidence angles, while abrupt changes from stable to unstable rolling moments were obtained at incidence angle of 20 degrees. Abrupt change of the rolling moment was strongly related to sudden increments of nose down pitching moments. Variations of suction peaks on pressure distributions at x/C(sub r) = 0.83 contribute to unstable rolling moment component. These variations of suction peaks that induce unstable rolling moment are related to the vortex breakdown characteristics. The asymmetry of the chordwise locations of the inboard vortex breakdown on windward and leeward wings induces the sudden change of rolling moments. Because of the effects due to retreating of the vortex breakdown on the leeward wing are larger than those due to moving forward of the vortex breakdown location on the windward wing, sudden increment of the nose down pitching moments was obtained., 風洞実験を行い、SST形態の低速高迎角ロール特性について調べた。模型のピッチ角を固定しロール方向に静的な運動を与え、空気力や翼表面静圧を計測した。また、前縁剥離渦の挙動を調べるためステレオPIV計測システムを用いて流速分布を計測した。低いピッチ角では線形的で安定なローリングモーメントが働くが、ピッチ角が増加するにつれ大きなロール角付近で非線形的なロール特性が見られた。特にピッチ角20度では小さいロール角の範囲ではロールに対して線形的で安定なモーメントが働くが、ロール角15度から25度付近で急激な変化が見られ、これらのロール角では不安定なローリングモーメントが働く。このピッチ角20度で見られた急激な不安定ローリングモーメントは翼表面静圧分布によると83％コード位置付近の流れが強く関係している。ロールにより下降した翼側のサクション・ピークの低下と上昇した翼側のサクション・ピークの増大が急激に不安定ローリングモーメントを増加させる方に寄与している。PIVによる流速分布計測結果によると、ピッチ角20度、83％コード位置で見られた不安定なローリングモーメントは内翼渦の崩壊(vortex breakdown)が強く関連している。ロール角0度の場合に比べ、ロールにより下降した翼側では渦崩壊位置は翼頂点に向かって前進し、これにより渦吸引力は減少し、逆にロールにより上昇する翼側では渦崩壊位置は後退し、渦吸引力は増加する。これらの渦崩壊位置の変化は不安定なローリングモーメントを発生させる。更には、下降した翼側のサクションの減少より上昇した翼側のサクションの増加が大きく、これにより機首下げピッチングモーメントの増加が発生している。, JAXA Research and Development Report, 宇宙航空研究開発機構研究開発報告

Published
2015

22. CFD analysis of the NEXST-1 using JAXA's code

Author

Ishikawa, Hiroaki, Kwak, Dongyoun, Lei, Zhong, 石川 敬掲, Ishikawa, Hiroaki, Kwak, Dongyoun, Lei, Zhong, and 石川 敬掲

Abstract

A flight test of a supersonic experimental airplane (NEXST-1: National EXperimental Supersonic Transport-1) was conducted successfully by JAXA in October 2005. In this study some aerodynamics design concepts were verified by comparing the flight test results with CFD (Computational Fluid Dynamics) analysis using JAXA's CFD codes, a structured mesh code UPACS (Unified Platform for Aerospace Computation Simulation) and an unstructured mesh code TAS (Tohoku university Aerodynamic Simulation). After the CFD codes was verified using a wind tunnel test results, the CFD results were compared with the flight test results. The aeroelastic deformation and the boundary layer transition data of flight test were taken into account to improve CFD analysis. The effect of the design concept of the NEXST-1 was also confirmed by CFD analysis., JAXA Special Publication, 宇宙航空研究開発機構特別資料

Published
2015

23. Experimental research of rolling moment characteristics on an SST configuration at high incidence angles

Author

Kwak, Dongyoun, Shirotake, Masashi, Noguchi, Masayoshi, Rinoie, Kenichi, and Watanabe, Shigeya

Subjects
ローリングモーメント, 静圧, separation vortex, 剥離渦, aircraft configuration, 風洞試験, rolling moment, SST, vortex breakdown, 渦崩壊, 圧力測定, static pressure, pressure measurement, 航空機配置, wind tunnel test
Abstract

風洞実験を行い、SST形態の低速高迎角ロール特性について調べた。模型のピッチ角を固定しロール方向に静的な運動を与え、空気力や翼表面静圧を計測した。また、前縁剥離渦の挙動を調べるためステレオPIV計測システムを用いて流速分布を計測した。低いピッチ角では線形的で安定なローリングモーメントが働くが、ピッチ角が増加するにつれ大きなロール角付近で非線形的なロール特性が見られた。特にピッチ角20度では小さいロール角の範囲ではロールに対して線形的で安定なモーメントが働くが、ロール角15度から25度付近で急激な変化が見られ、これらのロール角では不安定なローリングモーメントが働く。このピッチ角20度で見られた急激な不安定ローリングモーメントは翼表面静圧分布によると83％コード位置付近の流れが強く関係している。ロールにより下降した翼側のサクション・ピークの低下と上昇した翼側のサクション・ピークの増大が急激に不安定ローリングモーメントを増加させる方に寄与している。PIVによる流速分布計測結果によると、ピッチ角20度、83％コード位置で見られた不安定なローリングモーメントは内翼渦の崩壊(vortex breakdown)が強く関連している。ロール角0度の場合に比べ、ロールにより下降した翼側では渦崩壊位置は翼頂点に向かって前進し、これにより渦吸引力は減少し、逆にロールにより上昇する翼側では渦崩壊位置は後退し、渦吸引力は増加する。これらの渦崩壊位置の変化は不安定なローリングモーメントを発生させる。更には、下降した翼側のサクションの減少より上昇した翼側のサクションの増加が大きく、これにより機首下げピッチングモーメントの増加が発生している。, Wind tunnel tests were performed to investigate rolling moment characteristics of a cranked arrow wing SST configuration at high incidence angles. Force measurements and surface static pressure measurements were conducted with the model rolled statically. In order to understand behaviors of the leading edge separation vortex, stereoscopic PIV survey was performed at x/C(sub r) = 0.55 and x/C(sub r) = 0.83. With increasing roll angles, linearly stable rolling moments were obtained at low incidence angles, while abrupt changes from stable to unstable rolling moments were obtained at incidence angle of 20 degrees. Abrupt change of the rolling moment was strongly related to sudden increments of nose down pitching moments. Variations of suction peaks on pressure distributions at x/C(sub r) = 0.83 contribute to unstable rolling moment component. These variations of suction peaks that induce unstable rolling moment are related to the vortex breakdown characteristics. The asymmetry of the chordwise locations of the inboard vortex breakdown on windward and leeward wings induces the sudden change of rolling moments. Because of the effects due to retreating of the vortex breakdown on the leeward wing are larger than those due to moving forward of the vortex breakdown location on the windward wing, sudden increment of the nose down pitching moments was obtained., 資料番号: AA0048137000, レポート番号: JAXA-RR-04-028

Published
2005

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