Model updating for the aeroelastic ROM of a modern blisk

Kurzfassung

A simple updating procedure is presented accounting for mistuning deviations of a real UHBR fan rotor within its aeroelastic stability analysis. Traditionally the flutter analysis of such a configuration is performed via the energy method. This implies the assumption of a rotationally symmetric system with geometrically identical blades, which is rarely the case in reality. Based on the structural dynamics properties of the real rotor (determined by means of experimental modal analysis) the aeroelastic reduced order model (ROM), of the blisk can be updated with the DLR inhouse tool AEturbo, making use of the CFD outputs aerodynamic work and damping that have been generated previously for the tuned system. The stabilizing effect of this real mistuning pattern is demonstrated by a shift of the flutter boundary in the computed performance map - separately for three mode families as well as for the aeroelastic stability diagram as a whole.