TY - JOUR
T1 - The thrust and lift of an ornithopter's membrane wings with simple flapping motion
AU - Lin, Che Shu
AU - Hwu, Chyanbin
AU - Young, Wen Bin
N1 - Funding Information:
The authors would like to thank for the financial support from National Science Council in Republic of China under the contract number of NSC 93-2212-E006-067.
Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2006/3
Y1 - 2006/3
N2 - Human beings flying with the help of aircrafts of various kinds have been able to fly for about one century. Although the flapping wings of animals served as an inspiration to pioneers of human flight, we don't really understand how they work. In this study, we employ the concept of four-bar linkage to design a flapping mechanism which simulates a flapping motion of a bird. Wind tunnel tests were performed to measure the lift and thrust of the mechanical membrane flapping wing under different frequency, speed, and angle of attack. It is observed that the flexibility of the wing structure will affect the thrust and lift force due to its deformation at high flapping frequency. The lift force will increase with the increase of the flapping frequency under the corresponding flying speed. For the same flapping frequency, the flying speed can be increased by decrease of the angle of attack with the trade of loosing some lift force. An angle of attack is necessary in a simple flapping motion in order to derive a lift force. The flapping motion generates the thrust to acquire the flying speed. The flying speed and angle of attack combine to generate the lift force for flying.
AB - Human beings flying with the help of aircrafts of various kinds have been able to fly for about one century. Although the flapping wings of animals served as an inspiration to pioneers of human flight, we don't really understand how they work. In this study, we employ the concept of four-bar linkage to design a flapping mechanism which simulates a flapping motion of a bird. Wind tunnel tests were performed to measure the lift and thrust of the mechanical membrane flapping wing under different frequency, speed, and angle of attack. It is observed that the flexibility of the wing structure will affect the thrust and lift force due to its deformation at high flapping frequency. The lift force will increase with the increase of the flapping frequency under the corresponding flying speed. For the same flapping frequency, the flying speed can be increased by decrease of the angle of attack with the trade of loosing some lift force. An angle of attack is necessary in a simple flapping motion in order to derive a lift force. The flapping motion generates the thrust to acquire the flying speed. The flying speed and angle of attack combine to generate the lift force for flying.
UR - http://www.scopus.com/inward/record.url?scp=33644769134&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33644769134&partnerID=8YFLogxK
U2 - 10.1016/j.ast.2005.10.003
DO - 10.1016/j.ast.2005.10.003
M3 - Article
AN - SCOPUS:33644769134
SN - 1270-9638
VL - 10
SP - 111
EP - 119
JO - Aerospace Science and Technology
JF - Aerospace Science and Technology
IS - 2
ER -