ADAPTIVE-CONTROL OF AEROELASTIC INSTABILITIES IN TRANSONIC FLOW AND ITS SCALING

A two dimensional aeroservoelastic study in the time domain is describ ed. The model, based on exact inviscid aerodynamics, correctly represe nts the large amplitude motions and the associated strong shock dynami cs in the transonic regime. The aeroservoelastic system consists of a two-degree-of-freedom airfoil with a trailing-edge control surface. Ac tive flutter suppression in the presence of nonlinear aeroelastic phen omena is achieved using first-order actuator dynamics and a digital ad aptive controller, A relation between actuator dynamics and limits on the flap deflection angle to guarantee the effectiveness of the adapti ve controller is illustrated by the results. Hinge moment calculations and power requirements for flutter suppression are also carried out. Aeroelastic scaling requirements for the governing parameters, includi ng actuator moment and control power, are established.