@inproceedings{oai:jaxa.repo.nii.ac.jp:00005540, author = {小西, 康郁 and 高木, 正平 and Konishi, Yasufumi and Takagi, Shohei}, book = {宇宙航空研究開発機構特別資料: 境界層遷移の解明と制御研究会講演論文集 第40回, JAXA Special Publication: Proceedings of the 40th JAXA Workshop on Investigation and Control of Boundary-Layer Transition}, month = {Feb}, note = {It is well known that acoustic noise emanated from an airfoil trailing edge is discrete. The mechanism on why the noise becomes discrete and how the frequency is selected remains unclear. To reveal the mechanism, the boundary layer near the trailing edge on the pressure side was artificially disturbed with the use of distributed roughness elements. As a result, the separation is swept away and an acoustic sound is suppressed. The experimental results indicate that the frequency of trailing-edge noise is determined in separation region where mean velocity distribution has an inflection point accompanying reverse flow. These are necessary conditions for absolute instability., 資料番号: AA0063908019, レポート番号: JAXA-SP-07-026E}, pages = {61--64}, publisher = {宇宙航空研究開発機構, Japan Aerospace Exploration Agency (JAXA)}, title = {Observation of the feedback loop associated with airfoil trailing-edge noise}, volume = {JAXA-SP-07-026E}, year = {2008} }