Mecatheque
Results of collective works
Shaft line dynamics - Instabilities
Some aspects of the dynamic behaviour of the shaft lines of pumping installations are still poorly understood. In order to overcome this, Cetim's “Pumps” professional committee initiated an action on this subject, adopting a “simulation” approach. Firstly, a study was conducted to examine the dynamic behaviour of a vertical pump installation. This study took account of interactions with the equipment environment, in particular couplings between the fluid and the structure. The work then focussed on the existing methodologies and software tools for performing digital computation on a shaft line, with a focus on the interaction in operation between the rotor and the stator in bearing-type connections and seals. This new study explores the numerical methods for analysing the stability of a pump shaft. Demonstrators implementing the modal, frequency and time domain approaches were performed using the CodeAster finite element solver, then applied to a representative test case of a long shaft vertical pump. The results show that the demonstrators can be used as a starting point for carrying out numerical studies on real-life configurations.
Author : Yvon GOTH, Cetim
