Aeroelastic response analysis of a typical airfoil section with control surface structural nonlinearities

Abstract

In this paper, a typical airfoil section with control surface freeplay is studied. A type of friction nonlinearity in flap degree is designed to suppress the effect of freeplay nonlinearities. The Roger rational function fitting method is adopted to deduce the approximative expressions of the time-domain aerodynamic force, based on the coefficient matrices of unstationary aerodynamics in simple harmonic motion. The equations of motion are solved using the fourth-order Runge-Kutta numerical integration technique to provide time-history solutions of the aeroelastic response. The result shows that the adopted friction nonlinearities can effectively impair the airfoil nonlinear motion and prevent the aeroelastic response from various nonlinear behaviors when the airspeed is under the linear flutter speed. © 2014 Springer-Verlag.