Adaptive vortex generators based on active hybrid composites: from idea to flight test

In this contribution, we present a system of adaptive vortex generators (VGs) enabling an on-demand optimization of the airflow for high angles of attack. The generated vortices enhance the boundary layer with kinetic energy and prevent flow separation. The maximum cruise efficiency is ensured as VGs are stowed. The system presented uses active hybrid composites, where the actuation is initiated by shape memory alloys (SMA). By the direct integration of SMA elements in flat fiber-reinforced polymer (FRP) parts, the components turn into active hybrid composites. A well-selected amount of SMA wire is integrated in a composite layup and allows small elements of about 25 × 30 mm2 and a thickness of only 1.8 mm to deflect up to 8 mm upwards into the airflow. These small active VG with a weight of 1.5 g each can easily be integrated in the wing structure, since only an electrical connection is required. This contribution will highlight the actuation performance of these elements under airflow in the laboratory, illustrate the required system architecture and will give a first look on results of flight tests with functional setup equipped on a glider for measuring the aerodynamic impact on the flight behavior.