Abstract:

The dynamical equation of a two-dimensional airfoil with polynomial hysteresis nonlinearity in pitch is solved using Runge-Kutta time marching integration.Firstly,the bifurcation diagrams and power spectral densities of pitch and plunge motion are obtained;and it is found that as the existence of nonlinearity there are a number of frequency peaks in the spectrum,which lead to the bifurcation of the pitch amplitude.Then,the effects of airfoil/air mass ratio and plunge/pitch natural frequency ratio on flutter boundary are studied.

Key words: nonlinear , aeroelasticity,  , limit , circle , oscillation,  , Runge-Kutta , numerical , integration,  , hysteresis , nonlinearity,  , bifurcation,  , flutter , speed