Design of a Wind Tunnel Scale Model of an Adaptive Wind Turbine Blade for Active Aerodynamic Load Control Experiments

Within wind energy research there is a drive towards the development of a “smart rotor”; a rotor of which the loading can be measured and controlled through the application of a sensor system, a control system and an aerodynamic device. Most promising solutions from an aerodynamic point of view are trailing edge flaps, either hinged or continuously deformable. An experiment was considered necessary in which the effectiveness of such a system, with the interaction between dynamics, aerodynamics and control was tested. In order to perform this experiment, a blade needed to be constructed that had the scaled dynamics of a full scale blade as well as sufficient actuation power and sensors for measurements as well as feedback control. A blade was designed and tested with sufficient strength for high wind speed as well as an eigenfrequency (12.5Hz) that was close to the initial value (19.2Hz), derived from scaling the dynamics. Finally adapting the airspeed set the right dynamics. System identification was performed and a controller designed with which a significant reduction in vibrations was attained.