Influence of the blades configuration on the dynamics of a 3-bladed Jeffcott rotor
2015 (English)In: Proceedings of the 9th IFToMM International Conference on Rotor Dynamics / [ed] Paolo Pennacchi, Encyclopedia of Global Archaeology/Springer Verlag, 2015, Vol. II, 79-87 p.Conference paper (Refereed)
The nonlinear behaviour of blade rubbing has usually been investigated using complex modelling for the contact description. However, a simplified model of a 3-bladed Jeffcott rotor with nonlinear beam deformation contacting a fixed ring due to initial misalignment was used to unveil the global dynamic behaviour of the system. Chaotic regions were found at integer fraction of the natural frequency divided by the number of blades. Similarities in the global behaviour have also been observed for a model with rigid blades contacting a flexible casing. Even though the periodic and chaotic properties were observable experimentally, some difference occurred in localized frequency range due to material loss at the blade tip at higher speed. It is also difficult to accurately set all the blades with the exact same slight contact in experimental test rigs. As a result, the global properties of the rotor are also evaluated with two blades of the same length and the third one shorter. The extreme case where one or two blades are out is also investigated. The results are explored in terms of phase plots, Poincaré sections and bifurcation diagrams as function of the rotating speed. It can be seen that the inherent properties can be modified depending on the blades configuration and unbalance forces.
Place, publisher, year, edition, pages
Encyclopedia of Global Archaeology/Springer Verlag, 2015. Vol. II, 79-87 p.
Mechanisms and Machine Science, ISSN 2211-0984 ; 21
Research subject Computer Aided Design
IdentifiersURN: urn:nbn:se:ltu:diva-40036DOI: 10.1007/978-3-319-06590-8_7ScopusID: 84937509386Local ID: f01e92af-16bc-497b-95c2-749cf9ff6a48ISBN: 978-3-319-06589-2 (print)ISBN: 978-3-319-06590-8 (electronic)OAI: oai:DiVA.org:ltu-40036DiVA: diva2:1013558
IFToMM International Conference on Rotor Dynamics : 22/09/2014 - 25/09/2014
Validerad; 2015; Nivå 1; 20141118 (flothi)2016-10-032016-10-03Bibliographically approved