Effects of aerodynamic performance on flight formations of migratory birds

• Main Authors: Hung, Chih-Chia, 洪志佳
• Other Authors: Lo, Shih-Chieh
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/04125259054163102221

碩士 === 國立屏東科技大學 === 機械工程系所 === 102 === The performances of different flight formations of migratory birds are investigated by theoretical aerodynamics. Migratory birds such as the Canada geese usually arrange in a special array to reduce their flight drag during migration. In this research several different flight arrays are investigated to verify the optimized arrangement of migratory birds. We use Prandtl classical lifting line theory, Helmholtz vortex line theory, and Kutta-Joukowski theory to estimate the downwash and the induced drag acted on each bird. All the calculations are performed by an in-house Fortran program. Several different flight formations such as the V-shape, circle, square, vertical line, and horizontal line are investigated. The results have shown that the apex (or the leading) bird of the V-shaped formation suffers more induced drag than a single bird. The birds at the tail locations of the V-shaped formation suffer less induced drag than a single bird. Other formations do not have the same properties as the V-shaped formation, and are usually not adopted by the migratory birds.