Abstract
A rocket turbopump is the high-speed and high-power turbomachinery to feed the propellant to the engine and various rotor vibration problem had occurred in the past development. Rotordynamic fluid forces generated by the shaft seals is affects to the vibration characteristics of turbopump rotor. It has been reported that the floating ring seal often applied to rocket turbopumps has a stabilizing effect of rotor vibration. On the other hand, the component layout of the turbopump rotor also affects to the vibration characteristics. In this study, we investigate the effect of the component layout and shaft seal position on the rotor vibration characteristics by using complex eigenvalue analysis. Rotordynamic fluid force of floating ring seal is modelled using the cross-coupled stiffness. The results showed that the cross-coupled stiffness of the floating ring seal is effective to improve the modal damping ratios in some component layout. In addition, the effective position of floating ring seal on the turbopump rotor to stabilize the rotor vibration was described.
