A preliminary study of the aerodynamic characteristics of bird-scaled flapping wings is performed. Simulations of vortex behaviors and forces due to the reduced frequency of the three-dimensional flapping wings are investigated. First of all, numerical results of the flapping NACA0012 wing are verified with the experimental data. Secondly, three-dimensional leading edge vortex, tip vortex and trailing edge vortex contours induced by the flapping motions in a cycle are demonstrated. Finally, the current study is extended to discuss the flapping kinematics of a bird-size flapping wings. It is noted that the thrust and lift are enhanced and getting larger as the increasing reduced frequency of the flapping wing from 0.3 to 0.6 under Reynolds number of 60000.
Journal of Applied Science and Engineering 15(3), pp.257-264