Unsteady response of flow system around balance piston in a rocket pump

Abstract

In the rocket engine turbopump, a self-balancing type of axial thrust balancing system using a balance piston is often applied. In this study, the balancing system in liquid-hydrogen (LH 2 ) rocket pump was modeled combining the mechanical structure and the §ow system, and the unsteady response of the balance piston was investigated. The axial vibration characteristics of the balance piston with a large amplitude were determined, sweeping the frequency of the pressure §uctuation on the inlet of the balance piston. This vibration was signi¦cantly a¨ected by the compressibility of LH 2 .