Horizontal tail buffeting characteristics at wing vortex flow impact

Abstract

Modern, high-agility aircraft configurations often suffer from tail buffeting at subsonic speeds and medium to high angles of attack. This structural dynamic excitation through the unsteady flow field can result in heavy structural damage and degraded handling qualities. A flexible wind tunnel half model was developed at the Chair of Aerodynamics and Fluid Mechanics of the Technical University of Munich in cooperation with the Department of Acoustics and Vibration of Airbus Defence and Space. To provide enough flexibility, the wing and horizontal tail plane (HTP) are 3D-printed from polylactide (PLA). The model is used to experimentally analyze buffeting and to validate computational buffeting prediction. The objective of the present work is to examine aeroelastic phenomena with the modular designed flexible wind tunnel model. The measurement campaign takes place at the Göttingen type wind tunnel A. The model is equipped with various sensors. For unsteady pressure measurements on the surface of the wing and the HTP, piezo-resistive Kulite pressure transducers are installed on the wing and on the HTP. In addition, the flow field is described on the basis of numerical simulation results. For analyzing the structural response resulting from buffeting, miniature accelerometers are installed at the tips of the wing and the HTP. Strain gauges are used for calculating bending strains. As a reference case, a fully aluminum model is equipped correspondingly, but without strain gauges. Dominant frequencies corresponding to the structural eigenmodes can be identified and are excited in the PLA-setup (Buffeting). The unsteady pressure fluctuations on the surfaces act as the aerodynamic excitation input (Buffet). The measured tip accelerations of wing and tail are compared to simulation results with a one-way coupling CFD-CSM simulation.