The first experimental application of the Parametric Flutter Margin method for identification of aeroelastic instabilities is presented. The experiment was performed in two steps using a two degree-of-freedom wing segment mounted in the wind tunnel. First, the reference flutter and divergence conditions were found by increasing the free-stream velocity until the observed response diverged. Then, the system was stabilised according to the Parametric Flutter Margin methodology, and the flutter and divergence conditions of the original test model were identified positively while being in a stable regime demonstrating excellent agreement with the reference instability conditions. Although the new experimental methodology is not model based, the results were compared with a theoretical model showing good agreement as well. The acquired data demonstrates both the accuracy of the Parametric Flutter Margin method as well as its capability to test for aeroelastic instabilities, both flutter and divergence, in stable and predictable testing conditions.

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The first experimental application of the Parametric Flutter Margin method for identification of aeroelastic instabilities is presented. The experiment was performed in two steps using a two degree-of-freedom wing model mounted in the wind tunnel. First, the reference flutter and divergence conditions were found by increasing the airstream velocity until the observed response diverged. Then, the system was stabilized according to the Parametric Flutter Margin methodology, and the flutter and divergence conditions of the original wing were identified positively while being in a stable regime demonstrating excellent agreement with the reference instability conditions. Although, the new experimental methodology is not model based, the results were compared with a theoretical model showing good agreement as well. The acquired data proves both the accuracy of the Parametric Flutter Margin method as well as its capability to test for aeroelastic instabilities, both flutter and divergence, in stable and predictive testing conditions.

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A novel configuration of an energy harvester for local actuation and sensing devices using limit cycle oscillations has been modeled, designed and tested. A wing section has been designed with two trailing-edge free-floating flaps. A free-floating flap is a flap that can freely rotate around a hinge axis and is driven by trailing edge tabs. In the rotational axis of each flap a generator is mounted that converts the vibrational energy into electricity. It has been demonstrated numerically how a simple electronic system can be used to keep such a system at stable limit cycle oscillations by varying the resistance in the electric circuit. Additionally, it was shown that the stability of the system is coupled to the charge level of the battery, with increasing charge level leading to a less stable system. The system has been manufactured and tested in the Open Jet Wind Tunnel Facility of the Technical University Delft. The numerical results could be validated successfully and voltage generation could be demonstrated at cost of a decrease in lift of 2%.@en

In this paper, a novel configuration of an energy harvester for local sensing using limit cycle oscillations has been designed, modeled and tested. A wing section has been designed with two free-floating flaps. In the rotational axis of each flap a dynamo is mounted that converts the vibrational energy into electricity. It has been demonstrated numerically how a simple electronic system can be used to keep such a system at stable limit cycle oscillations by varying the resistance in the electric circuit. Additionally it was shown that the stability of the system is coupled to the charge of the battery, with increasing charge level leading to a less stable system.

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