Research On Active Deformation Aerodynamic Characteristic Of Flexible Wing For Small Aerial Vehicle Based On Piezoelectric Material

Small aerial vehicle(SAV)is suitable for the airspace of complex terrain as urban area and mountains.Due to its small size and the aerodynamic characteristic of low Reynolds number,gust disturbance in these flying environments has been the key problem to restrict the development of SAV.The active deformation flexible wing can make the airfoil deformed adaptively by driving elements,so as to improve the aerodynamic characteristic and achieve the effect of gust alleviation.The traditional servo-control-surface may increase the quality of the aircraft,and destroy the continuity of the airfoil.With the development of aeronautics and astronautics,intelligent material,especially piezoelectric material,has gradually replaced the traditional servo-driven mode.The application of piezoelectric material driving method solves the problems of continuous deformation and timely response of the airfoil.This thesis summarizes common intelligent materials,and obtains the advantages of piezoelectric material in driving active deformation of flexible wing.The piezoelectric fiber composite(MFC)is chosen as the driving element for active deformation of flexible wing,due to its easy installation,wide frequency response and short response time.First,the influence of gusts on SAV is introduced,and the dynamic response of flexible wing is analyzed.Based on this,the static aerodynamic model is established,and the relevant aerodynamic parameters are calculated by an iterative optimization program AeroBeamSaw.Based on the simulation results,the feasibility of active deformation in improving the aerodynamic characteristic is proved.Secondly,the mechanical property of the piezoelectric material is analyzed,and its driving equations are obtained.For the piezoelectric composite flexible wing structure,the relationship between the wing's twist angle and the driving voltage of the piezoelectric material is obtained.Finally,an experimental platform about active deformation of flexible wing for SAV based on piezoelectric material is built.The feasibility of active deformation of flexible wing is proved qualitatively.