Mechanism Design And Aerodynamic Analysis Research On Bird-like Flapping-wing Air Vehicle

Bird-like FAV(Flapping-wing Air Vehicle)is an attractive research topic at home and abroad given its excellent abilities of stealth,low noise,high maneuver ability,which will contribute to extremely widespread application prospect in the military and the civil fields.FAV will certainly be regarded as an important issue in this research field and have great significance to the development of aerial technology.The main content of this thesis is as follows:Firstly,taking the example of birds,this article comprehensively expounded the high lift performance of bird flight in terms of the body structure,flight mode,and the motion posture of wings.Secondly,based on classic graphical method on four-bar linkage mechanic,the function relation between minimum transmission angle and the length of FAV was established.Also,by simulating the natural bird,installation angle,flap-wing flapping range and the function of rocker driven angle were introduced.An optimization design model was obtained by utilizing Matlab and was proved to conform with FAV flapping theory by a virtual kinetic simulation which's been conducted by utilizing ADAMS,and these provide a base for the design of the FAV mechanism.Thirdly,this thesis made a further step to describe the driving mechanism,the flapping wing structure and tail structure design of Bird-like FAV in detail.The size of each part and the model of the main auxiliary equipment are determined with the actual machining.The three dimensional model was drawn by UG.The driving mechanism of the bird-like flapping-wing not only realizes symmetric flutter of the left and right wing,but also realizes bending-folding movement of the wing.A 3D model of Bird-like FAV was established based on overall dimensions of bird and a Multi-Degree-of-Freedom motion model of “swing-torsion-bending and folding” was built.The flapping-wing air vehicle of multi-DOF is numerically simulated in the case of unsteady flow at low Reynolds number by XFlow software.What's more,this thesis analyzed both the effects of vortex structure,spanwise velocity and pressure of surrounding air and the influence of flight angle,flapping-wing bending-folding,wing shape,and frequency of liftand drag coefficient.The simulation results provide theoretical and technical support for the research and development of flapping-wing air vehicle.