Aerodynamic Performance Research Of Bionic Wing Based On Pigeon Wings

Unmanned aerial vehicle(UAV)is a hot spot in the world.The wing is the core component of the lift,and the aerodynamic characteristics of the airfoil are very important to the aerodynamic performance of the UAV wing.The flying pigeon has a strong flying ability,and the small UAV working environment is similar to the flight principle of the pigeon.Therefore,the pigeon wing's bionics prototype is applied to the high flying mechanism of homing pigeons,which provides a new way for the design of high performance UAV wings.The analysis of the structure of the pigeon wings and feathers:pigeon wings short and wide,The feather is divided into primaries,secondaries and coverts,Primaries inside and outside the plume area has obvious asymmetry,This feature helps to reduce air resistance in flight;The feather has the hydrophobicity and anisotropy,which is beneficial to the surface cleaning and is beneficial to the long flight.Using motion capture technique to obtain the motion posture of the wing in a cycle.Measuring the geometric parameters of wing flutter attitude by reverse engineering,interception of the wing patterns is performed on airfoil in aspect ratio10%-90%,and gained the wing section geometry parameter.The parameters fit the surface profile of the airfoil and the middle arc.Airfoil meshing is extracted using ICEM software,Numerical simulation on the aerodynamic characteristic using FLUENT software under the condition of using Reynolds number of 7×10~4and 8×10~4,The results show that the lift coefficient of 30%airfoil is 2.4 times of that of the standard airfoil at Re=7×10~4,and the rise and drag ratio of the 90%airfoil is 54%higher than that of the standard airfoil at 4degree angle of attack.The biological aerodynamic characteristics analysis found that:(1)static pressure curve area of bionic airfoil is bigger than standard airfoil,the bionic airfoil lift is high;the lift coefficient of airfoil wing aileron section is high,aileron section of wings is the main source of lift;(3)the main wing section of the airfoil leading edge radius and small thickness,airfoil resistance is low,high lift resistance,strong flexibility;(4)under the attack angle of 16 degrees,the upper surface of the pigeon wing has no stall on the surface,and the airfoil is stable.The UAV wing analysis of bionic design and numerical simulation,the following conclusions are obtained:(1)when the attack angle is 0-30 degrees,the lift coefficient of the bionic wing is greater than that of the original wing.When the attack angle is20 degrees,the lift coefficient of the bionic wing reaches the maximum and the maximum lift coefficient is 0.65,which is 1.13 times of the original airfoil.The bionic wing has higher stall characteristics.Under 10m/s wind speed,the drag coefficient of bionic wing and original wing is not very different.The lift coefficient of bionic wing is much larger than that of original wing,so the aerodynamic efficiency of bionic wing is better.(2)the upper surface of the biomimetic wing is subjected to positive pressure,and the positive pressure area is mainly distributed in the aileron section,so the aileron is the main source of the lift.The stall angle of the bionic airfoil and the bionic wing is greater than 15 degrees,and the negative pressure area has little effect on the aerodynamic efficiency of the wing.The bionic wing positive pressure area and the original wing positive pressure area is the similar,and the resistance coefficient is similar;The pressure difference at the 30%section,70%section and 90%section of the bionic wing is larger than that of the corresponding section of the original wing.The lift coefficient of the bionic wing is higher than that of the original wing,and the aerodynamic characteristics are stronger than the original wing.The rapid prototyping technology is applied to the processing of pigeon airfoil,standard airfoil,bionic wing and original wing,and a small wind tunnel test rig is used to perform the aerodynamic test on the above sample.The experimental results show that the 10m/s of the wind speed,the maximum lift coefficient of airfoil section30%,followed by the 20%and 40%section airfoil,80%section airfoil lift drag ratio is maximum,followed by the 90%section airfoil;When the attack angle is 0-30degrees,the total lift of bionic wing is higher than that of the original wing,the resistance value is the same,the experimental results are in agreement with the simulation results.The results show that the bionic wing has excellent aerodynamic performance.