32th Congress of the International Council of the Aeronautical Sciences

04.2 - Aerostructures Design, Structural Dynamics, Aeroelasticity


Y.X. Liu¹, D. Mo¹, Q. Du¹, Y.Z. Chen¹, M. Wang¹; ¹AECC Shenyang Engine Research Institute, China

This paper aims at exploring the primary characteristics of fan blade flutter and compressor non-synchronous vibration (NSV) phenomenon by experimental investigation and numerical simulation. The multi-physical field synchronized measurement was implemented to monitor the dynamic stress, pressure fluctuation, blade tip vibration at the same time. The features of fan blade flutter at 0.75 corrected speed and compressor NSV at idle condition were achieved and compared. Afterwards, the corresponding aero-work and aerodynamic damping were obtained using the phase-shifted energy approach. Results show both flutter and NSV occupied locked phase and frequency, non-integer engine order excitation and nodal vibration features. However, the flutter demonstrated a forward wave vibration with 4 nodal diameter whereas NSV showed a backward wave vibration with 13 nodal diameter. Furthermore, flutter was found near the surge line with sharply increased stress to 187Mpa within seconds while the NSV would maintain a large stress level near the idle working line. The total aero-work for flutter was positive while it was negative for NSV, which implies that the aerodynamic damping was not enough to curb the vibration during flutter. The numerical simulation is consistent with experimental results.

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