Numerical simulations of subsonic aeroelastic behavior and flutter suppression by active control

A method for predicting the unsteady, subsonic, aeroservoelastic response of a wing has been developed. The air, wing, and control surface are considered to be a single dynamical system. All equations are solved simultaneously in the time domain by a predictor-corrector method. The scheme allows nonlinear aerodynamic and structural models to be used and subcritical, critical, and supercritical aeroelastic behavior may be modeled without restrictions to small disturbances or periodic motions. A vortex-lattice method is used to model the aerodynamics. This method accounts for nonlinear effects associated with high angles of attack, unsteady behavior, and deformations of the wing. The vortex-lattice method is valid as long as separation or vortex bursting does not occur. Two structural models have been employed: a linear model and a nonlinear model which accounts for large curvature. Both models consider the flexural-torsional motion of an inextensional wing.