抄録
One of the main problems in development of the rocket engine is the vibration problem of the fuel turbopump（FTP）. In
this study, both the rotor dynamic fluid forces and the damping effect at the bearing supports are considered, and the derivation
of reduced order model of FTP by utilizing the complex modal analysis technique is demonstrated. By using the
derived reduced order model, the variation of the modal damping ratio for the rotor dynamic fluid forces and the damping at
the bearing support are explained. The resonance curve of the modal amplitudes for various unbalance distribution cases are
compared, and it is validated that modal amplitude is predictable from the mode shape, the modal unbalance, and modal
damping ratio. Furthermore, the peak amplitudes of the dominant modes are focused, and the influence of the rotor dynamic
fluid forces and the damping at the bearing supports on them are explained.
