Analysis of Active Flutter Suppression with Leading- and Trailing-Edge Control Surfaces via <italic>μ</italic> -Method

The robust stability of an active wing section with leading- and trailing-edge control surfaces is investigated using μ-method. Mathematical models and implementation issues of active flutter suppression are described. The multi-input/multi-output aeroservoelastic systems and algorithms are developed by μ-control law to account for the uncertainty parameters/perturbations associated with the unsteady dynamic pressure, the variable structural damping and the nonlinear structural stiffness. The nominal and robust stability margins, modal properties, critical flutter airspeeds and frequencies are computed to predict the flutter of the aeroelastic system and to investigate the aeroservoelastic stability in μ-framework. The simulation results are presented for the comparisons among: a) the uncontrolled wing section, b) the active wing section with a single trailing-edge flap controller (K1) activated, and, c) the one with both the leading- and trailing-edge flap controllers (K2 and K1) activated to demonstrate the improved effectiveness for flutter suppression by using two control surfaces.