Dynamic Stability of Rotating Systems in Turbomachinery Under API Standards
2019
scientific article
english
- turbomachinery
- rotating system stability
- model tuning
- API standards
EN The stability of rotating systems in turbomachinery has to account for the structure design, the actual geometry of bearings and all of the remaining forces, including operational data as well as temperature of the bearing lubricating oil. Thus, a study of the dynamic stability of rotating machines is complex and time consuming in terms of modelling and calculations. Even though it is recognized that other methods of analysis and acceptance criteria have been used to evaluate stability, API standardization procedures ensure appropriate notification and participation in the development process. According to these procedures, firstly we prepare a rotor technical documentation based on geometry measurements, frequently with optical scanning. Secondly, a theoretical analysis consisting of calculations with the finite element method based on the program that allows us to build a numerical model of rotor dynamics, is carried out. Then, the so-called “bump test” is performed to measure natural frequencies of a freely suspended rotor, which makes it possible to “tune” the theoretical model, making it compatible with the real object not only in terms of geometric dimensions and mass, but also from the point of view of the form and frequency of free vibrations. Thus, we obtain an experimentally verified numerical model which can be used for future machine diagnostics and other needs.
2019202-1 - 2019202-8
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