Aiming at the experimental test of the body freedom flutter for modern high aspect ratio \nflexible flying wing, this paper conducts a body freedom flutter wind tunnel test on a full span \nflying wing flutter model. The research content is summarized as follows: (1) The full span finite \nelement model and aeroelastic model of an unmanned aerial vehicle for body freedom flutter wind \ntunnel test are established, and the structural dynamics and flutter characteristics of this vehicle are \nobtained through theoretical analysis. (2) Based on the preliminary theoretical analysis results, the \ndesign and manufacturing of this vehicle are completed, and the structural dynamic characteristics \nof the vehicle are identified through ground vibration test. Finally, the theoretical analysis model is \nupdated and the corresponding flutter characteristics are obtained. (3) A novel quasi free flying \nsuspension system capable of releasing pitch, plunge and yaw degrees of freedom is designed and \nimplemented in the wind tunnel flutter test. The influence of the nose mass balance on the flutter \nresults is explored. The study shows that: (1) The test vehicle can exhibit body freedom flutter at \nlow airspeeds, and the obtained flutter speed and damping characteristics are favorable for \nconducting the body freedom flutter wind tunnel test. (2) The designed suspension system can \neffectively release the degrees of freedom of pitch, plunge and yaw. The flutter speed measured in \nthe wind tunnel test is 9.72 m/s, and the flutter frequency is 2.18 Hz, which agree well with the \ntheoretical results (with flutter speed of 9.49 m/s and flutter frequency of 2.03 Hz). (3) With the \nincreasing of the mass balance at the nose, critical speed of body freedom flutter rises up and the \nflutter frequency gradually decreases, which also agree well with corresponding theoretical results.
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