Aerodynamic Performance Study of Bionic Blade Inspired by the Seagull Wing

摘要

It is demonstrated that a three-dimensional bionic airfoil model was presented from the seagull wing as bionic prototype, which was fittingly constructed by using bionic reconstruction method. In this research, the bionic airfoil and the NACA 4412 airfoil were uniform section and fixed wing model based on 40% cross-section of seagull and NACA 4412 respectively. The low speed flow over the bionic airfoil compared with the NACA 4412 airfoil was simulated numerically assuming that the flow was steady. The aerodynamic performance of two airfoils against the angle of attack with the range of 0°~30° were analyzed at low Reynolds number related to the chord length of 75000. The results showed that the bionic airfoil based on the seagull possessed decent lift characteristics due to its forward convex and upward bent structure. And more specifically, not only the max lift coefficient enhanced 32.27% than the NACA 4412 airfoil but also the stall angle was delayed to 27°. In addition, how the flow condition varied and the laminar separation bubble moved with the increasing attack angle were analyzed in this paper. The present study revealed the flow control mechanisms of bionic blade inspired by the seagull wing and proved that the surrounding flow condition of the bionic airfoil was better than that of the NACA 4412 airfoil.