Wind tunnel testing and modal validation of TU-Flex's high aspect-ratio wings

Abstract

High aspect ratio flexible wing aircraft present very complex and coupled structural and flight dynamics. This research describes a bottom-to-top validation process for this type of wing. This procedure starts with static, followed by ground vibration and wind tunnel tests. The concept of this approach is to first validate the structural and aeroelastic models before addressing the full flying vehicle. The experimental data was used to tune the structural model of a flexible flying demonstrator called TU-Flex. This aircraft was designed as a flying lab capable of recording coupled flight dynamic data of a flexible aircraft with a transport/airliner configuration. Three software were used to design the wing and to define the experimental test cases: NASTRAN, Loads Kernel, and ModSiG. The gathered data permitted tuning and showing the accuracy of the structural model. It also allows for finding inaccuracies in the aerodynamic and aeroelastic models for further tuning. The models are capable of capturing the overall aeroelastic trend nevertheless, fine tuning is now necessary. Therefore, the proposed process seems adequate to collect all necessary data to tune aeroelastic models within the process to prepare the models for the full flying vehicle.