EXPERIMENTAL INVESTIGATIONS OF AN AEROELASTIC WIND TUNNEL MODEL FOR TAIL BUFFETING ANALYSIS

Modern high-agility aircraft are often affected by the consequences of buffeting phenomena. At higher angles of attack, vortex bursting results in a strongly unsteady flow field downstream of the breakdown region. High turbulence intensities and their distinct burst frequency content lead to structural dynamic excitation of the wing and downstream located elements such as tail planes. Subsequently, heavy structural damage and degraded handling qualities may occur. Buffeting is an important numerical and experimental research field because of its complexity and criticality in future aircraft designs. A wind tunnel model has recently been developed at the Chair of Aerodynamics and Fluid Mechanics of the Technical University of Munich (TUM) for the experimental analysis of buffeting effects. The full-span model was designed based on the experience obtained from previous investigations on an aeroelastic half-span model. To ensure structural elasticity, the wings, the horizontal tail planes (HTPs), and the vertical tail planes (fins) are 3D-printed from polylactide (PLA). As roughly rigid reference cases, aluminum wings, HTPs, and fins can be mounted on the modular model configuration. The HTP's deflection angle can be adjusted by means of the HTP being rotatably mounted on the aluminum fuselage. In the context of this work, the aerodynamic characteristics as well as aeroelastic phenomena of the newly manufactured wind tunnel model are investigated experimentally. The focus lies on the analysis and comparison of the aerodynamic coefficients of the rigid and the flexible cases as well as on their sensitivities. Based on the experience gained from the force and moment measurements, signals of unsteady pressure transducers and accelerometers integrated into the lifting surfaces will be analyzed.