Design And Analysis Of Active Folding And Flapping Winged Aircraft

The bionic flapping wing aircraft is currently the most promising aircraft because it has various functions such as take-off,acceleration,hovering,etc.and has good maneuverability and high flight efficiency.There are two main types of flapping wing aircraft developed in China:one is two-stage wing and the other is non-deformed wing.However,both of the wings are non-foldable and deformable along the wing surface direction,so the wing is so rigid that it is easily damaged,difficult to carry,and has poor flexibility.Therefore,it has great significance to study the deformation structure of birds'wings and their skeletal motion mechanism,and to apply them to the design of flapping wing aircraft for application of flapping aircraft in the future.This subject mainly uses medium and large birds' wings as bionic objects,and designs and develops three kinds of flap-wing aircraft that can be actively deformed.Then simulates and studies them.The specific research contents are as follows:First of all,from the perspective of bionics,based on the analysis of the bird wing structure and the movement mechanism of the skeletal system,this subject designed the single joint folding mechanism and the multi-joint folding mechanism respectively,and the kinematics and mechanical analysis of the mechanism are applied by vector method.Established the relationship between the parameters.Then,according to the bird scale law formula,each bionic parameter is initially determined,and designed the parameters of the two foldable mechanisms based on the bionic parameter.Finally,the 3D model of the folding mechanism is established in SolidWorks,and then the simulation analysis of the folding motion of the multi-joint folding mechanism is carried out by ADAMS.The results show that the multi-joint folding mechanism has good folding performance.Secondly,based on the analysis of bird flight mechanism and law,and the design of collapsible mechanism,this subject designed the single joint active deformation flapping wing aircraft,single-stage multi-joint active deformation flapping wing aircraft and two-stage multi-joint active deformation flapping wing aircraft.And draw its 3D model.Then,through the ADAMS,the kinematics and mechanical analysis of the three active-formed flapping-wing aircraft in the fluttering motion are carried out to verify the motion feasibility of the active-formed flapping-wing aircraft and provide guidance for the prototype manufacturing.The results show that the flapping performance of the three active-form flapping-wing aircraft is excellent and the inner and outer wing movements of the two-stage active-form flapping wing aircraft meet the design goals.Third,the numerical simulation of the aerodynamic characteristics of the aircraft wing is carried out.Based on the theory of fluid mechanics and computational fluid dynamics,the dynamic mesh method is used in FLUENT to select the pressure field and velocity field around the wing at different deformation levels to simulate and generate the lift and drag characteristics.The results show that the aircraft has greater lift when the wing is deformed to a greater extent,so it should have sufficient flexibility to deform the wings.According to the above analysis and design,the prototype selection of the materials of the parts of the flapping wing aircraft and the preliminary preparation of the machining process were determined,and the prototype was tested.The experiment showed that the prototype achieved the design goal.The main performance values of the prototype were determined by different experimental methods and simulation analysis.