Research On Dynamic Characteristics Of Deformation Wing Driven By Parallel Mechanism

Traditional aircraft can no longer meet the increasing demand of people for flexibility,economy and versatility,and variant aircraft has become a research hotspot.This type of aircraft can adjust the aerodynamic load distribution and size by changing its shape to adapt to the complex flight environment,especially the deformation of wing has become one of the key points in the research of variant aircraft.In this paper,a deformable wing driven by parallel mechanism is proposed,which can realize the quick adjustment of the curvature and chord length of the trailing edge.The kinematics,structural mechanics and aerodynamics of the deformed wing were analyzed.The influence of different flight conditions on the dynamic characteristics of the deformed wing was studied by the fluid-structure coupling simulation.A prototype of the deformed wing principle was developed to verify the feasibility of the deformation method.This paper expounded the deformation principle of the deformed wing,analyzed the kinematic characteristics of the internal parallel mechanism of the deformed wing,established the kinematic model of the parallel mechanism;the forces on the deformed wing in flight were analyzed,and after simplifying the leading edge and the trailing edge into members the mechanical model of the statically indeterminate structure was established based on the force method.Based on the thin airfoil theory and Karman-Tsien formula,the lift model of the wing deformation process was established.The influence of the angle of attack and the flight speed on the lift of the wing was analyzed.The influence of the initial angle of attack,trailing edge length and the flight speed on the lift coefficient in the process of trailing edge rotation is analyzed.Based on the finite element theory and the finite volume method,the fluid-structure coupling model of wing deformation process was built.The influence of flight speed on the dynamic characteristics of wing was analyzed.The aerodynamic forces of the deformed wing and the forces on the bar in subsonic flight and supersonic flight were compared,and the similarities and differences between them were pointed out.In addition,the special flight conditions such as takeoff,landing and ultra-low altitude penetration were discussed.Finally,the effects of flight height and wing deformation velocity on the deformation process of the deformed wing were studied,the aerodynamic parameters and the force on the bar were obtained,and the influence rules were summarized.The prototype of the deformed wing principle was designed.After testing,it was found that the prototype can achieve the desired deformation,which verified the feasibility of parallel mechanism driven deformation.