Reduced-order-model-based flutter analysis at high angle of attack

Reduced-order-model (ROM)-based flutter analysis of a delta wing at high angle of attack is constructed by using computational fluid dynamics (CFD). The flutter characteristics of a 70 deg cropped delta wing at different angles of attack before the vortex breakdown are studied. The identification techniques is used to construct the reduced-order model based on the structural modes. Time linear ROM is suitable for studying the unsteady flow due to small amplitude vibration of a delta wing before the vortex breakdown and can be employed to delta wing flutter analysis at high angle of attack. The flutter mode may change at a certain angle of attack and a cusp appears on the flutter boundary.