Wind tunnel experiment for body freedom flutter of flying wing unmanned aerial vehicleifasd2024 Tracking Number 108 Presentation: Session: Flutter testing Room: Room 1.1 Session start: 13:30 Thu 20 Jun 2024 Hao Wei, Elijah Ang ELIJ0001@e.ntu.edu.sg Affifliation: Jieli, Daryl Leo DLEO001@e.ntu.edu.sg Affifliation: Jun Kang Tan JTAN472@e.ntu.edu.sg Affifliation: Chien Ming, Jonathan Tay jonathan_tay@nus.edu.sg Affifliation: Yongdong Cui tslcyd@nus.edu.sg Affifliation: Bing Feng Ng bingfeng@ntu.edu.sg Affifliation: Topics: - Experimental Methods in Structural Dynamics and Aeroelasticity (Experimental methods), - Wind Tunnel and Flight Testing (Experimental methods) Abstract: Body Freedom Flutter (BFF) has always been known to be a potentially catastrophic event for any flying aircraft. BFF is a dynamic instability that is the result of strong coupling between rigid-body and elastic modes of the aircraft. In this presentation, we demonstrate how different parameters affect the speed and frequency at which BFF occurs using a wind tunnel with a novel test rig. The novel test rig was designed to allow the degrees of freedom needed for BFF to occur, which is then fabricated using 3D printing to optimise weight savings. Different flying wing profiles are considered and the UAV is subject to the different parameter variations. The mount allowed the wing profile to freedom in both the pitch and plunge movement. It is found that BFF characteristics are affected by the wing swept angle, additional wing tip weights, and spanwise weight location. These parameters directly affect the centre-of-gravity for the wing profile, its wing inertia, and its structural properties. The results and trends obtained can then be potentially used to further understand the BFF phenomenon in the future. |