Dynamic Wind Tunnel Measurements of a Forward-Swept Laminar Wing at Flight-Relevant Conditions using a Pitch Oscillator

Kurzfassung

This paper presents dynamic wind tunnel measurements conducted within the DLR projects ECOWING and ULTIMATE on a forward-swept semi-span wing with natural laminar flow. A novel pitch oscillator enables unsteady testing across a range of oscillation amplitudes and frequencies. Unsteady pressure data showed some discrepancies from steady-state conditions, with slight increases in standard deviation, particularly near shock locations. In contrast, acceleration measurements revealed significant dynamic response, with higher oscillation amplitudes and frequencies inducing pronounced wing vibrations - especially near the model trailing-edge. These results underscore the importance of dynamic testing for capturing unsteady aerodynamic and, even more significantly, aeroelastic behavior. The developed capability unlocks realistic unsteady aerodynamic and aeroelastic investigations in the European Transonic Wind Tunnel, providing critical data for validating numerical simulations under flight-relevant conditions.