Numerical Study Of The Aerodynamic Performance And Stress Analysis Of The Dragonfly Wing Sections In Gliding Flight

In view of the rapid development of bionics and microelectronics technology improvement, micro flapping wing flight vehicle design and manufacturing have become more and more mature, its widely application in military and civilian also calls for the further development of the micro flapping wing flight vehicle, however the aircraft with small size and relative slow flight is different from the traditional crafts, its resistance will increase when it flight in the air, traditional way of aerodynamic layout and the flight is not suitable for such aircrafts, these will bring great difficulties to the development of MAV, so according to the characteristics of the tiny machine itself we should design new and adaptable fly way under the current technology.This paper will be combined with bionics and fluid mechanics, and used Fluent to simulate the flow field structures about the front dragonfly wing in 2D and 3D. we get the corresponding conclusions as follow:First, we simulate the gliding pleated airfoils in 2D flow field, and combine with the structures and parameters of five section wings along the spanwise of dragonfly front wing to build airfoil models, the angle of attack is from 0 to 25 ° respectively we calculate the lift of drag coefficients and solve the lift-to-drag ratio of five sections, as the Angle of attack increasing, close to the wingtip of the airfoil produces a small negative lift, so that the flat wings won’t produce bending and keep flat.Second, after finished the calculation of two-dimensional gliding airfoils, select the best aerodynamic performance pleated airfoil, embedded dynamic grid technique, make the pleated airfoil asymmetric flapping, by calculating we explain flow field structures changes in one period, compare to the smooth airfoil NACA –M1 from NACA database according to the lift and drag curve of pleated airfoil and smooth airfoil we can get the conclusion: the pleated airfoil wing has higher lift performance than the smooth profile. Further studies show that the most suitable dragonfly flapping amplitude is 2—3cm.Finally, subdivision of dragonfly wings with 10 along the spanwise of wing section, get the corresponding profile data, and combining the 3D data dragonfly wings with the plane 2D airfoils. The first step, software Fluent is used to calculate the three dimensional airfoil lift and drag, and apply these aerodynamic forces on the dragonfly surface, calculate the displacement, stress and strain by software ANSYS Workbench module, analyze the effect of pleated structures on strength and toughness of dragonfly wings.These results are expected to be useful for design and affrication of micro air vehicles.