Optimized Design Of Bio-inspired Flapping Wing Micro Aerial Vehicles For Flight Performance

Inspired by flying creatures in nature,biomimetic micro flapping-wing micro air vehicles possess exceptional flight capabilities similar to those of flapping-wing animals.Due to their outstanding flight performance and high biomimetic similarity,biomimetic micro flapping-wing aircraft have broad application prospects in various fields such as military and civilian,and have become a hot topic of research both domestically and internationally.This thesis focus on improving the various flight capabilities of micro flapping-wing aircraft and conduct a series of research studies,including the following aspects:Firstly,based on the current research,a biomimetic micro flapping-wing aircraft with a T-shaped tail consisting of three rudders has been designed,including the design of its flapping mechanism,wings,and tail.In addition,the aerodynamic performance of the prototype has been theoretically analyzed,the morphology and kinematics of the wings have been described,and the aerodynamic forces of the wings have been analyzed based on the blade element theory and quasi-steady method.The aerodynamic forces of the tail have been analyzed using traditional aerodynamics,and the overall aerodynamic forces of the flapping-wing prototype have been obtained using a rotation matrix.Secondly,to test the flight performance of the bionic micro flapping-wing aircraft,an aerodynamic experimental platform suitable for the research object was constructed,including a physical aerodynamic experimental platform based on F/T sensors and a simulation aerodynamic experimental platform based on Xflow.In addition,an experimental method was proposed to test the aerodynamic characteristics of the bionic micro flapping-wing aircraft,including the implementation steps of physical and simulation aerodynamic experiments,as well as the method of processing raw experimental data.Finally,the aerodynamic forces and torque characteristics of the micro flapping-wing aircraft under various operating conditions were tested through physical and simulation aerodynamic experiments.Thirdly,in order to improve the flapping lift performance of the biomimetic micro flapping-wing aircraft,the biomimetic wings of the flapping-wing prototype have been optimized.The significance of the influence of each design parameter of the wings on the flapping lift has been analyzed by orthogonal experiment to determine the optimization variables of the wings.The optimal Latin hypercube design method has been used to sample the design space,and high-and low-fidelity aerodynamic responses have been obtained through physical aerodynamic experiments and CFD simulations,respectively.Furthermore,a variable-fidelity aerodynamic surrogate model of the wing parameters and flapping frequency with respect to the flapping lift has been constructed using the Cokriging method,and the accuracy of the model has been validated through physical aerodynamic experiments.Finally,a mathematical optimization model of the wing has been established based on the Cokriging model of the flapping lift with the average flapping lift of the flapping-wing prototype within the operating frequency range as the objective.The PSO algorithm has been used for optimization,and comparative experiments have been implemented to verify the optimization effect.Finally,in order to enhance the turning performance of the bionic micro flappingwing aircraft,the geometric parameters of each rudder of the T-tail were optimized.The significance of the influence of each parameter on the aerodynamic performance of the flapping-wing prototype was explored through an orthogonal experiment to determine the optimized variables of the rudder.The optimal LHD method and physical aerodynamic experiment were used to obtain sampling and aerodynamic responses,and then the Kriging method was used to construct aerodynamic surrogate models for three types of turning modes.Finally,a multi-objective optimization mathematical model for each rudder was established with the average aerodynamic lift and moment of the flappingwing prototype within the range of rudder deflection angle as the objective,and the MOPSO algorithm was used to solve the optimization and the optimization effect was verified through comparative experiments.