Characteristics of fluid structure interactions due to leading edge vortex systems impact

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Slender wings with moderately up to highly swept leading edges create a system of leading edge vortices to achieve high maneuverability in the sub- and transonic regime. For high angles of attack, the leading edge vortices experience a structural change in the form of vortex bursting, which is associated with a highly turbulent flow field downstream of the bursting location with concentrations of the turbulent kinetic energy in certain frequency ranges. This type of flow can, on the one hand, excite the wing that generates it and, on the other hand, components located downstream, such as horizontal and/or vertical tails, to strong structural vibrations. This dynamic aeroelastic problem is known as buffeting, the excitation forces of which result in the present case from the unsteady aerodynamic forces that prevail in the case of separated flow and vortex bursting. Relative to the large experimental and numerical data base for leading edge vortex flow on surfaces that are more or less treated as rigid, only very few studies are available for the coupled probelm of unsteady flow and structural vibrations. The present project is therefore intended to detail the interaction of flow physics and structural dynamics through complementary experimental and numerical analyzes on a modular model configuration. The configuration consists of a double delta wing to generate an interfering leading edge vortex system as well as a horizontal tail and a twin vertical tail. The model structure for wing and tail components is provided to include both rigid and structurally elastic parts. This approach enables to quantify the respective contribution in the flow structure interaction through a systematic permutation of components to clearly highlight dominant effects in the aerodynamic excitation characteristics on structurally elastic surfaces. The results will create a previously unavailable database and contribute to a more precise approach to aircraft design as well as to refined numerical prediction capabilities.