Forced and Self-Excited Oscillations in Propellant Lines

Abstract

Analytical techniques used to model the dynamics of propellant feed systems of rocket engines are presented as well as experimental results which provide verification. The laboratory hydraulic system, consisting of suction pipe, centrifugal pump, and discharge pipe, provides longitudinal fluid oscillations which are analyzed by use of linear methods employing a distributed parameter representation of the pipes. Of particular interest is the effect of the pump upon pressure oscillations when the pump is operating under cavitating conditions. A self-excited instability caused by the interaction between hydraulic and structural portions of the system is also described.