Effects of Angles of Attack on Flutter Characteristics of A Cropped Delta Wing

Abstract

§By using unsteady aerodynamic reduced order models based on Euler codes, and coupling with structural moving equations, an aeroelastic analysis model is constructed in state-space. The flutter characteristics of a 70°cropped delta wing at high angles of attack are studied. The results (both flutter speed and flutter frequency) by ROM analysis method agree well with those by CFD direct simulation method. It shows time linear ROM is suitable for studying the unsteady flow due to small amplitude vibration of delta wing before vortex breakdown, it can be employed to delta wing flutter analysis at high angle of attack. The flutter critical speed greatly reduces with the increasing angle of attack. It shows a 22% decrease of the flutter speed index at by comparing with . The flutter branch may change with the increasing angle of attack lead to a discontinuity in flutter characteristics. 20 α = D 0 α = D