Numerical study of a variable camber plunge airfoil under wind gust condition

Abstract

Variable camber deformation is observed during the flight of some insects and bird species; however, the effect of this special airfoil shape motion on the aerodynamic characteristics of the airfoil is not well understood, especially for the airfoil under gust wind. We did a numerical study to investigate the aerodynamic characteristics of a variable camber plunge airfoil under wind gusts. A weak coupling program was developed to simulate the interaction between the variable camber plunge airfoil and fluid, and the flow field, aerodynamic force and energy efficiency of different camber airfoils under different wind gust conditions are investigated. It was found that camber deformation influences the aerodynamic characteristics of the airfoil greatly. If the airfoil has an appropriate camber deformation, the deformation can increase the mean thrust and the propulsive efficiency of the airfoil. Moreover, the aerodynamic characteristics of the appropriate camber airfoils are not significantly affected by the gust frequency, and there exists a range of gust amplitude where the aerodynamic characteristics of the airfoils are also not significantly affected by the gust amplitude, which may be beneficial for aerodynamic stability of the airfoil. The results also show that appropriate camber deformation can suppress leading edge vortex separation, which improves the aerodynamic characteristics of the airfoil.