@techreport{oai:jaxa.repo.nii.ac.jp:00002274,
 author = {徳川, 直子 and 高木, 正平 and 上田, 良稲 and 井門, 敦志 and Tokugawa, Naoko and Takagi, Shohei and Ueda, Yoshine and Ido, Atsushi},
 month = {Feb},
 note = {e(sup N)法を用いた2次元および3次元境界層の乱流遷移位置の予測において外乱の影響を定量的に評価するため、一様流の残留乱れTuおよび騒音レベルSPLと遷移位置における撹乱の空間増幅率Nの相関関係を実験的に調べた。気流特性が異なる3つの風洞で同一の矩形翼NACA0012模型の遷移計測を実施した。その結果、模型を2次元と3次元形態のどちらに設置しても、NはTuの対数とSPLの1次関数で表されるが、外乱に対する感度は翼断面や後退角に依存することがわかった。この相関関係を用いることにより2次元の場合には遷移位置の予測精度が翼弦長の10％程度向上することが期待される。また低亜音速境界層の遷移位置検出手法として、赤外線力メラを用いた表面温度分布計測が有効であり、横流れ定在渦も可視化可能であることを示した。, A series of experimental investigations have been carried out to examine the influence of free-stream turbulence and acoustic noise on laminar-to-turbulent transition in boundary layers on an NACA0012 airfoil. The quantitative evaluation of the influence on the total growth rate N of the most amplified disturbance obtained from the e(sup N) method at the transition location is made in an empirical relation between the total growth rate N and both the residual turbulence Tu and the sound pressure level SPL. Consequently, the transition location is detected as a linear equation N = C(sub Tu) x ln(Tu) + C(sub SPL) x SPL + C for not only 2-D case with zero angles of both sweep and attack but also 3-D case with non-zero angles of both sweep and attack, though each coefficient in N depends on geometrical configuration of airfoil such as cross-sectional shape and swept angle. Accuracy of predicted chord length is expected to be improved 10 percent by use of the obtained empirical relation. Surface temperature measurement technique by use of infrared camera is shown to be efficient and useful for transition detection in low subsonic flow. Usefulness is also shown in visualizing cross-flow stationary vortices growing in 3-D boundary layer., 資料番号: AA0049194000, レポート番号: JAXA-RR-05-017},
 title = {NACA0012翼境界層の自然遷移に対する外乱の影響},
 year = {2006}
}