UHBR Open-Test Case Fan ECL5/CATANA: Non-Linear Analysis of Non-Synchronous Blade Vibration at Part-Speed Conditions

The onset of non-synchronous vibrations has been predicted for a composite open-test-case UHBR fan geometry by time-linearized simulations at part-speed conditions. In the current study, time-accurate simulations with harmonic blade oscillations have been conducted to investigate the non-linear behavior. Results for different operating conditions show the evolution of aeroelastic stability. The lock-in of convected aerodynamic disturbances with structural vibration is analyzed for different vibration amplitudes and frequencies. The simulations show the development of multiple wave numbers, mode scattering, and a non-linear dependency on vibration amplitude. The results indicate the possibility of limit-cycle prediction and the necessity of strongly coupled methods for the assessment of non-synchronous vibration.