Non-Linear Phenomena in Aero-Engine Rotor Vibration

This paper describes a test facility which reproduces the essential features of a twin-rotor assembly for a medium-size jet engine. Its purpose is to investigate phenomena experienced in an actual engine, which relate to system non-linearities. These phenomena include subharmonics, combination oscillations and jumps in frequency response. All such phenomena manifested themselves in the test facility and explanations are given as to their cause and possible elimination.