NLR experience in the application of active flutter suppression and gust load alleviation, applied to a wind-tunnel model

In 1981 NLR started a research programme to study the aeroelastic effects of active control systems. Control laws for flutter suppression and gust load alleviation systems were developed and tested using an aeroelastic wind-tunnel model in a subsonic wind tunnel with the capability to simulate discrete or random gusts. Flutter suppression up to the maximum wind-tunnel speed (1.4 V ) was achieved, while the gust load alleviation system reduced the wing root bending moment with 25 percent at 0.9 V for simulated gusts with a Dryden spectrum.