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A Design of Multi-Element Aerofoils for High Lift
https://jaxa.repo.nii.ac.jp/records/44886
https://jaxa.repo.nii.ac.jp/records/448869e4b9c46-42ee-4f7c-ad65-0c2099edf3d9
| 名前 / ファイル | ライセンス | アクション |
|---|---|---|
naltr00631.pdf (1.1 MB)
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| Item type | テクニカルレポート / Technical Report(1) | |||||||||
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| 公開日 | 2015-03-26 | |||||||||
| タイトル | ||||||||||
| タイトル | A Design of Multi-Element Aerofoils for High Lift | |||||||||
| 言語 | en | |||||||||
| 言語 | ||||||||||
| 言語 | eng | |||||||||
| 資源タイプ | ||||||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_18gh | |||||||||
| 資源タイプ | technical report | |||||||||
| その他のタイトル | ||||||||||
| その他のタイトル | 低速で高揚力を得るための多翼素翼型の設計 | |||||||||
| 著者 |
重見, 仁
× 重見, 仁
× SHIGEMI, Masashi
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| 著者所属 | ||||||||||
| 航空宇宙技術研究所新型航空機研究グループ | ||||||||||
| 著者所属（英） | ||||||||||
| en | ||||||||||
| V/STOL Aircraft Research Group, National Aerospace Laboratory(NAL) | ||||||||||
| 出版者 | ||||||||||
| 出版者 | 航空宇宙技術研究所 | |||||||||
| 出版者（英） | ||||||||||
| 出版者 | National Aerospace Laboratory(NAL) | |||||||||
| 書誌情報 |
航空宇宙技術研究所報告 en : Technical Report of National Aerospace Laboratory TR-631 巻 631, p. 15, 発行日 1980-10 |
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| 抄録（英） | ||||||||||
| 内容記述タイプ | Other | |||||||||
| 内容記述 | A method to design multi-element aerofoils for high lift in an incompressible flow, together with a few examples, is presented. Some kinds of velocity distribution around aerofoils have been developed recently in order to obtain high lift through the aerofoils. When, however, those single-element aerofoils are examined, which were designed to realize the velocity distribution, they appear to be impractical for wings of airplanes because of their very thick or highly cambered shape. Most of the practical airplanes in service, on the other hand, aquire high lift through the introduction of high-lift devices such as flaps or slats. Therefore, it seems reasonably effective to obtain high lift by combining the velocity distribution developed for high lift with multi-element aerofoils. Our velocity distribution for the upper surface of aerofoils is composed of two parts; uniform velocity distribution for the former laminar part, and the Wortmann’s velocity distribution for the latter turbulent part. Among the many possible combinations of the two kinds of distributions, the one which leads to the highest lift is chosen. The velocity distribution for the lower surface is arbitrarily arranged. The velocity distribution thus decided for the whole contour is imposed only on the main element, and the geometries of the flap and slat are assumed to have been prescribed. The velocity distributions around the flap and the slat, therefore, can not be determined until the geometry of the main element is designed to meet the given velocity conditions. The geometry of the main element is created in an iterative correction way with the aid of the panel method for a two-dimensional potential flow. The starting geometry of a three-element aerofoil is chosen at the beginning. While the main element of it will be improved iteratively to satisfy the prescribed velocity condition, the shapes of the flap and the slat are maintained until the end of the iteration procedure. Then, the velocity around the starting geometry is calculated with the panel method, in which velocity distributions around the elements can be regarded as equivalently equal with the vortex distributions planted around their contours. If the velocity distribution around the main element, thus calculated, is the same as the one prescribed, the starting geometry appears to be the objective geometry. In most cases, however, both velocity distributions do not agree as a result of the inappropriate selection of the starting geometry, and the improvement of the geometry becomes necessary in following way. As a requirement for the boundary condition in the panel method, the normal velecity components, induced from the free stream and the vortices around the contours, are diminished on the row of descrete points on the aerofoil. When, however, the calculated vortex distribution around the main element is replaced with the one prescribed, which is easily obtained from the prescribed velocity distribution, the normal velocity components on the aerofoil do not become zero. The geometry of the main element is so improved that the total sum of the squared residuals, calculated on a row of discrete points on the elements, are minimized. Due to the practical requirement of the evaluation, the formula of the panel method, which related the normal velocity component to the coordinates of the aerofoil, is linearized approximately in terms of the coordinates. This procedure is repeated untill the desired geometry is achieved. Three examples of multi-element aerofoils which are designed for high-lift are shown, including one which is modified from another in order that the flap and the slat can be nested to construct a unified aerofoil. It is shown that such a modification of the shape of the aerofoil does not cause a disadvantage to the velocity distribution along it. The lift coefficients experienced with our aerofoils are predicted to be about 4.3 with a theoretical calculation for the potential flow. | |||||||||
| ISSN | ||||||||||
| 収録物識別子タイプ | ISSN | |||||||||
| 収録物識別子 | 0389-4010 | |||||||||
| 資料番号 | ||||||||||
| 内容記述タイプ | Other | |||||||||
| 内容記述 | 資料番号: NALTR0631000 | |||||||||
| レポート番号 | ||||||||||
| 内容記述タイプ | Other | |||||||||
| 内容記述 | レポート番号: NAL TR-631 | |||||||||
