Verification and application of fluid-structure interaction and a modal identification technique to cascade flutter simulations

Abstract

This paper presents the verification and application of the flutter analysis framework using fluid-structure interaction simulation (FSI). This approach is verified by consulting semi-analytical reference solutions from LINSUB. Aeroelastic eigenmodes and mode shapes obtained by FSI are compared; the proposed approach is found to be capable of accurately obtaining flutter characteristics, even under the presence of aerodynamic coupling between structural modes. This verified approach is applied for predicting the flutter boundary of part-speed transonic stall flutter, which is experienced during the rig test. The flutter boundary obtained by FSI simulations agrees well in a qualitative sense for the high speed lines. However, the simulations cannot reproduce the end of the flutter boundary for the low speed lines. The reason for the mismatch in the flutter boundary is discussed, and it is concluded that highly complex and sensitive near-wall flow phenomena are related to the shock position and flutter characteristics.