University of Electro-Communications
University of Electro-Communications
University of Electro-Communications
Institute of Physical and Chemical Research Advanced Computing and Communication Center
出版者
宇宙航空研究開発機構
出版者（英）
Japan Aerospace Exploration Agency (JAXA)
雑誌名
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39回
雑誌名(英)
JAXA Special Publication: Proceedings of the 39th JAXA Workshops on Investigation and Control of Boundary-Layer Transition
巻
JAXA-SP-07-009
ページ
27 - 30
発行年
2007-12-28
抄録（英）
Using a high-speed video camera, we have recorded the trajectory and the rotation of a hard baseball and a sphere thrown by pitching machines. We measured the drag and lift coefficients by analyzing the video images. We altered pitching machines on the market in order to throw a 'gyro-ball', whose rotational axis lies almost in the translational direction. The drag coefficient of a gyro-ball decreases with the Reynolds numbers (Re). For a fast-ball, the drag coefficient doesn't depend on Re and the lift coefficient is increases with the Re and the Spin Parameter (SP). The drag coefficient of a sphere is larger than that of a baseball for fast- and gyro-pitches, indicating that seams on the ball surface have substantial influence on the flow field.
硬式野球ボールに働く流体力の測定
63608009.pdf
(545.71KB)
