Q. Rendu, S. Aubert, P. Ferrand
DOI Number: N/A
Conference number: IFASD-2017-164
Choke flutter appears when a strong shock-wave chokes the blade to blade channel. The blades vibration lead to the oscillation of the shock-wave. This induces a dynamic loading of the structure which can lead to an aeroelastic instability. In the present work, the physical mechanisms leading to the instability (flutter) are identified through 2D linear RANS aeroelastic computations. A linear decomposition shows that the vibration of the blades downstream of the shock-wave generates a backward travelling pressure wave driving the aeroelastic stability. A local analysis of the downstream vibration demonstrates the destabilising contribution of the shock-wave / separated boundary layer interaction. The source of flutter is finally a combination of inviscid (acoustic blocage) and viscous (unsteady separation) mechanisms.