Shaft Vibration Analysis of A Cryogenic Turbopump Test Rotor

(1st report, Experimental modal analysis of a rotor assy under room temperature condition)

Abstract

A severe vibration of a liquid rocket turbopump may cause not only the functional failures but also catastrophic failures of the rocket engine that leads to the mission failure. In order to improve the reliability of the prediction of the rotor dynamic (RD) properties of a cryogenic turbomachinery, authors try to build a precise finite element model of a cryogenic turbo pump test rotor. As the first stage of the model construction, this report aims to identify the vibration characteristics of a test rotor at room temperature and in a dry condition. Impact test was performed to the test rotor at every assembly stage. From the measured transfer functions, the resonance frequencies of the first and second bending mode of the rotor were successfully identified as 1004.5 Hz and 2446.5 Hz, respectively, and the vibration mode shapes were also identified.