Research On Surface Characteristics Based On Airfoil

In order to further study the surface of the bionic coupling and drag reduction characteristic,improve the utilization efficiency of the airfoil,this paper chose pigeon wings as the research object,the surface configuration and drag reducing mechanism of pigeon wing were discussed,and the distribution of macro structure and microstructure of wing,the effects of different surface structures on aerodynamic parameters of airfoils are discussed,and the best surface structure data are obtained.Through the reverse modeling of the surface of the wing of the pigeon,the parameter variation interval of the wing structure is obtained,the spacing of the oval groove of the flying feather layer f1 is 15-20mm,the long axis e1 of the elliptical groove is 0.5-1mm,and the short axis e2 is 0.3-0.5mm.The continuous convex hull short axis L1 is 8-12mm,the long axis size L2 is 10-15mm,the spacing D1 is 13mm,D2 is 17mm.Using the bionic coupling technology to design the surface,establish a multi coupling bionic surface model which is different from the traditional single element surface design.The chord length of the wing of the pigeon is set to 1 by the normalization method,the ratio of the maximum thickness to the string length is 0.146,and the NACA0015 standard airfoil is selected according to the general example of the bionic airfoil design,and NACA0015Based on the airfoil,a variety of single bionic airfoil and multi coupling bionic airfoil are designed and optimized.A variety of bionic airfoils are compared and analyzed.The influence of different bionic structures on aerodynamic performance of airfoil is summarized,and the protruding structure of the front edge of the wing of the pigeon wing,the structure of the outer edge sawtooth,the characteristics of the groove between the feathers and the surface continuous convex hull are the direct factors of wings has good aerodynamic performance.When the Reynolds number is1.58×10~5and the Maher number is 0.073,the NACA0015 airfoil has the best performance when the angle of attack is 16degrees.The maximum increase rates of single bionic convex airfoil,elliptical groove airfoil,continuous convex hull airfoil and multiple coupled bionic airfoil are 23.7%,3.7%,5%and25.2%respectively,and the maximum drag reduction rates are 12.48%,1.7%,2.3%and15.4%respectively,when the attack angle is 16 degrees.