An Experimental Approach to Determine the Aerodynamic Pitch Damping Coefficient of Slender Bodies in the Transonic Regime

摘要

The objective of the present research is to develop an experimental setup in order to study the dynamic stability of slender bodies in the transonic regime. A semi-free oscillation approach is chosen to determine the aerodynamic damping coefficient. Based on the potentials of the installation environment (VKI S-1 Supersonic-Transonic wind tunnel) a wire suspension system is proposed. The nondimensionalized oscillation frequency is preserved between the flight vehicle and the wind tunnel model by a cable tensioning mechanism enabling the adjustment of the natural frequency. The oscillation of the test model is decomposed by a boundary identification technique applied to high-speed camera recordings. The analysis of the oscillation amplitudes yields the total damping. To separate the mechanical and the aerodynamic contributions tare measurements are performed without flow.