@inproceedings{oai:jaxa.repo.nii.ac.jp:00002954,
 author = {山田, 健翔 and 鈴木, 宏二郎 and Yamada, Kento and Suzuki, Kojiro},
 book = {宇宙航空研究開発機構特別資料: 第50回流体力学講演会/第36回航空宇宙数値シミュレーション技術シンポジウム論文集, JAXA Special Publication: Proceedings of the 50th Fluid Dynamics Conference / the 36th Aerospace Numerical Simulation Symposium},
 month = {Feb},
 note = {第50回流体力学講演会/第36回航空宇宙数値シミュレーション技術シンポジウム (2018年7月4日-6日. 宮崎市民プラザ), 宮崎市, 宮崎, 50th Fluid Dynamics Conference /the 36th Aerospace Numerical Simulation Symposium (July 4-6, 2018. Miyazaki Citizen's Plaza), Miyazaki, Japan, A bubble-type vortex breakdown is known as a topological change of streamlines. Topological approaches from the aspect of the dynamical system theory are promising to elucidate the fundamental structure of the vortex breakdown and classify the geometrical features into various classes. In this paper, in order to clarify a relation between a bifurcation process of the topology of streamlines and tensor invariants of the velocity gradient tensor, a bubble-type vortex breakdown was numerically simulated and the invariants of the velocity gradient tensor were examined. Our result showed that the structure of a longitudinal vortex was highlighted by the negative discriminant of the velocity gradient tensor and a minimum velocity inside the bubble-type vortex breakdown was on a surface where its determinant was zero., 形態: カラー図版あり, Physical characteristics: Original contains color illustrations, 資料番号: AA1830029025, レポート番号: JAXA-SP-18-005},
 pages = {199--203},
 publisher = {宇宙航空研究開発機構(JAXA), Japan Aerospace Exploration Agency (JAXA)},
 title = {バブル型渦崩壊現象の軌道構造とテンソル不変量に関する考察},
 volume = {JAXA-SP-18-005},
 year = {2019}
}