An investigation into the dynamic response of a squeeze-film damped twin-shaft test rig

Abstract

This paper performs a theoretical and experimental analysis of a twin-shaft test rig in which the two unbalanced rotors are nonlinearly coupled through the flexible housing of a squeeze-film damper bearing, as in a real aircraft engine. The research aims are twofold: to validate recently developed fast computation methods; to achieve an insight into the effect of the ratio between the rotor speeds on the overall vibration response. The experimental data correlated reasonably well with the theoretical analysis. The correlation was best when the speed ratio was equal to a ratio of large integers (in its most reduced form). When the speed ratio was a ratio of two low integers, the predicted response was found to be particularly sensitive to the arbitrary initial phase angle between the rotors.