Grant-in-Aid for Scientific Research (B)
|Research Institution||Osaka Prefecture University|
OHTA Hirobumi Osaka Prefecture University, Faculty of Engineering, Professor, 工学部, 教授 (00023317)
KATO Michiyo Nagoya University, School of Engineering, Research Associate, 工学部, 助手 (30109277)
NITTA Kyoko Nagoya University, School of Engineering, Research Associate, 工学部, 助手 (30189328)
|Project Fiscal Year
1994 – 1996
Completed(Fiscal Year 1996)
|Budget Amount *help
¥7,600,000 (Direct Cost : ¥7,600,000)
Fiscal Year 1996 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1995 : ¥3,700,000 (Direct Cost : ¥3,700,000)
Fiscal Year 1994 : ¥3,300,000 (Direct Cost : ¥3,300,000)
|Keywords||Circular wing / Flying disk / Frisbee / Dynamics of flying disk / Aerodynamics of flying disk / Stability and control / Spin stabilization / Flight control / 円形翼 / フライングデイスク / フリスビ- / 空力特性 / 運動解析 / 安定操縦性 / スピン安定化 / 飛行制御 / フライングディスク / 飛行安定性 / フライイングディスク|
This research is concerned with the theoretical and experimental development on the aerodynamic and dynamic characteristics of flying vehicles with spinning circular wing. The study aims are to develop the following two subjects which are not examined so far and of academic interest.
(1) Aerodynamic characteristics of spinning circular wing
Aerodynamic center of the conventional airplanes is located near a quarter chord point, and negative pitching moment is generated around the point. The aerodynamic location and its moment are not known when the wing is rotated.
The wind-tunnel experiments were done on the circular wings with several aerofoils. The results show that the aerodynamic characteristics with the Frisbee aerofoil are different from the Disk and other aerofoils because of the concave lower surface. Specifically, the Frisbee aerofoils has
* larger lift and drag coefficients, high stall angle of attack. and almost constant lift-to-drag ratio with angle of attack.
* low negative pit
ching moment coefficient around the spinning axs, while the moments of the other aerofoils are positive.
* The effects of spinning of the wings on the surrounding air are negligible because of the unnoticeable unsymmetory between the right and left side streams.
(2) Dynamic characteristics of spinning circular wings
It is shown that the stability is improved with the increase of the spin rate. The ground trajectory of a flying Frisbee shows curved one on the left with left bank angle when the wing is rotating right on the top view. The left curved trajectory is caused due to a small positive pitching moment, which generates the change of the roll angle with the phase lag of 90 degrees. The derail examination from both experiment and simulation reveals that the pitching moment of Frisbee changes with the angle of attack from a small negative value to a small positive one around the angle of attack of 20 degrees. This causes the Frisbee curve on the left side during deceleration with high sink rate.
(3) Development of flight control theories
A number of the recent control theories such as the H infinity robust control, nonlinear control, control of time delay systems, and adaptive control are examined and the design methods of flight controllers are developed. Less