Dragonfly Flapping-Wing Air Vehicles Design And Test Research

After thousands of years of evolution,the flapping wing flight has already been widely applied to birds and insects,including the advantages of fixed wing and rotor craft flying,it can quickly take off,acceleration,hovering,with high mobility and flexibility.In recent years,the micro air vehicle has become a hot topic in the field of aviation,and it can be used as the object of our study.For birds,the lifting mechanism of the single wing flight has made considerable technological achievements,but for the dragonfly such double wings of the insect research is still in its infancy.Dragonflies show great superiority in flapping flight of insects,mainly in:it is less by two pairs of wings flapping insects,can be easily implemented before flying,climbing,gliding and steering mode of flight;A dragonfly has a low Reynolds number of the unsteady mechanism combined with traditional flight mechanism into the best way of flying,so for the researches on the mechanism of the dragonfly flying dragonflies and the analysis of the different flight mode choice for the application of double wings flapping wing flight vehicle is of great significance.Firstly,a brief concept of MAV,characteristics and ground application prospect are introduced,the current domestic and foreign theory and prototype research status and achievements are summarized,the key problems and difficulties of flapping-wing micro vehicle(FLMAV)are analyzed.Secondly,I analyzes the wings flapping process of birds and insects,contrasts the differences between two flight modes,study the mechanism of insect flight,the high lift mechanism of insect flapping wing flight are explained using unsteady aerodynamics.Thirdly,a kind of double-wing spatial four-bar flapping wing mechanisms are put forward,the kinematics analysis is carried on,the flapping wing structure parameters are calculated,3D model is designed and motion simulation is carried out,I bases on the traditional mechanical design and mechanical analysis,dynamic model was established by applying the Lagrange equation,dynamics simulation analysis by using Adams software,aerodynamic load and moment of inertia of the vehicle stability and efficiency are analyzed.In addition,Based on the unsteady aerodynamics force model,the dynamic model of dragonfly flapping-wing air vehicle is established,aerodynamic force and moment are analyzed and the contrast analysis of lift and drag coefficient change between the different phase difference during the double-wing swinging(In-phase,a difference of 1/4 period,anti-phase)is performed in this study,which can provide a theoretical basis for selection of different flapping model.Lastly,for each link in the transmission mechanism of dimension,and design the required motion pair were determined,and the position such as motor,steering gear is determined.to determine the vehicle's transmission ratio,flapping frequency,wingspan,wing area and other important parameters of flight are used by scaling law.The whole 3D model was built and assembled in Pro/E software,and the motion simulation was carried out by using Adams software,which provided the basis for the research and improvement of the prototype.