Transonic flutter suppression control law design and wind-tunnel test results

Flutter suppression control law design and wind-tunnel test results in transonic flow for a NACA 0012 wing model, under the benchmark active control technology program at NASA Langley Research Center, will be presented. Two control law design processes using classical and minimax techniques are described. Design considerations fur improving the multivariable system robustness are outlined. The classical control law was digitally implemented and tested in the NASA Langley Transonic Dynamics Tunnel. In wind-tunnel tests in air and heavy gas medium, the closed-loop Butter dynamic pressure was increased by over 50% up to the wind-tunnel upper limit. The active Butter suppression system also provided significant robustness, relative to gain and phase perturbations, even in the presence of transonic shocks and Row separation.