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剥離を伴ふ層流境界層の計算法に就て : ポールハウゼンの解法の再檢討
https://jaxa.repo.nii.ac.jp/records/36593
https://jaxa.repo.nii.ac.jp/records/365935cef5d0e-b8da-484e-bf50-7b68121ee243
| 名前 / ファイル | ライセンス | アクション |
|---|---|---|
SA4433918.pdf (718.2 kB)
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| Item type | 紀要論文 / Departmental Bulletin Paper(1) | |||||||
|---|---|---|---|---|---|---|---|---|
| 公開日 | 2015-03-26 | |||||||
| タイトル | ||||||||
| タイトル | 剥離を伴ふ層流境界層の計算法に就て : ポールハウゼンの解法の再檢討 | |||||||
| 言語 | ||||||||
| 言語 | jpn | |||||||
| 資源タイプ | ||||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_6501 | |||||||
| 資源タイプ | departmental bulletin paper | |||||||
| 著者 |
野田, 親則
× 野田, 親則
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| 出版者 | ||||||||
| 出版者 | 東京帝國大學航空研究所 | |||||||
| 書誌情報 |
東京帝國大學航空研究所彙報 巻 178, p. 194-205, 発行日 1939-06 |
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| 抄録（英） | ||||||||
| 内容記述タイプ | Other | |||||||
| 内容記述 | Tikanori NODA: On the calculation of laminar boundary layer involving separation. According to the suggestion of Prof. Tani two modifications of the approximate solution due to Pohlhausen are tried. The method of solution is just the same as that of the original. Assuming the velocity distribution across the layer in cubic and sine forms respectively, we obtain the differential equation to be solved in the form [numerical formula] where x is the distance along the surface of the obstacle, U the velocity of stream at the edge of boundary layer, z is equal to δ^2/ν (δ thickness of layer, ν kinematic viscosity), and λ means zdU/dx The equation may also be written fully in terms of x and λ: [numerical formula] where dashes represent differentiation with respect to x. Since functions f(λ), g(λ) and h(λ) are independent of the particular problem considered, their numerical values are tabulated for practical use. The present solutions are compared either with other solutions or with experiment. For instance, when the velocity distribution is expressed U=kx^<-m>, skin friction vanishes everywhere for appropriate value of m. Our methods give m=0.928 and 0.0908 respectively compared with the exact value 0.0905. Next if we write U=b_0-b_1x, separation occurs when x^*=b_1x/b_0 reaches to 0.132 and 0.115 according to the present methods. Corresponding value of x^* obtained from the Howarth's method is 0.120, which is considered as the most accurate value ever known. Finally we applied our solutions to the Schubauer's experiment on an elliptic cylinder. The first modification gives no separation and λ reaches -4.8 (separation takes place where λ becomes -6). The second methods gives separation point at x/L=1.92, where x is measured from the forward stagnation point and L is the length of minor axis. The position of separation is x/L=1.925 calculated by the Howarth's method whereas the observed value was 1.99. It must be noticed that original Pohlhausen's method gives no separation and λ reaches only -7.5 (λ corresponding to separation point is -12). Both modifications differ from the original method in one respect that they are unapplicable at the stagnation point. Therefore in the present paper a quadratic distribution of velocity accross the layer is used, as a remedy, for the region between the stagnation point and the point of maximum U. At the latter point this solution is succeeded by each of our methods so that the momentum thickness connects without discontinuity. Though the skin friction jumps at this joint, the above described remedy seems to be plausible to find the position of separation. | |||||||
| 書誌レコードID | ||||||||
| 収録物識別子タイプ | NCID | |||||||
| 収録物識別子 | AN00162779 | |||||||
| 資料番号 | ||||||||
| 内容記述タイプ | Other | |||||||
| 内容記述 | 資料番号: SA4433918000 | |||||||
