Nonlinear rotor dynamic design of turbine-generator shaft trains applying numerical continuation

Γαβαλάς, Ιωάννης; Gavalas, Ioannis

dc.contributor.author	Γαβαλάς, Ιωάννης	el
dc.contributor.author	Gavalas, Ioannis	en
dc.date.accessioned	2022-07-21T08:01:21Z
dc.date.available	2022-07-21T08:01:21Z
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/55461
dc.identifier.uri	http://dx.doi.org/10.26240/heal.ntua.23159
dc.rights	Αναφορά Δημιουργού 3.0 Ελλάδα	*
dc.rights.uri	http://creativecommons.org/licenses/by/3.0/gr/	*
dc.subject	Dynamics	en
dc.subject	Turbomachinery	en
dc.subject	Numerical continuation	en
dc.subject	Stability	en
dc.subject	Limit cycles	en
dc.title	Nonlinear rotor dynamic design of turbine-generator shaft trains applying numerical continuation	en
dc.title	Μη γραμμικός δυναμικός σχεδιασμός στροβιλογεννητριών με εφαρμογή αριθμητικής συνέχισης	el
heal.type	bachelorThesis
heal.classification	Rotordynamics	el
heal.language	en
heal.access	free
heal.recordProvider	ntua	el
heal.publicationDate	2022-02-22
heal.abstract	The nonlinear dynamics of turbine generator shaft trains for power generation are investigated in this thesis. Realistic models of rotors, pedestals, and nonlinear bearings of partial arc and lemon bore conﬁguration are implemented to compose a non-linear set of differential equations for autonomous (balanced) and nonautonomous (unbalanced - per ISO) cases. The solution branches of the dynamic system are evaluated with the pseudo arc length continuation programmed by the author, and the respective limit cycles are evaluated by an orthogonal collocation method, and investigated on their stability properties and quality of motion for the respective key design parameters for the rotordynamic design of such systems, namely: bearing proﬁle and respective pad length, preload and offset, pedestal stiffness and elevation (misalignment), and rotor slenderness. Model order reduction is applied to the ﬁnite element rotor model and the reduced system is validated in terms of unbalance response and stability characteristics. The main conclusion of this thesis is that the system has the potential to develop instabilities in rotating speeds lower than the threshold speed of instability (evaluated by the linear approach) for speciﬁc unbalance magnitude and design properties. Unbalance response (with stable and unstable branches) is evaluated in severely reduced time compared to this applying time integration methods, enabling nonlinear rotor dynamic design of such systems as a standard procedure, and revealing the complete potential of motions (not only local).	en
heal.advisorName	Χασαλεύρης, Αθανάσιος	el
heal.committeeMemberName	Χασαλεύρης, Αθανάσιος	el
heal.committeeMemberName	Αντωνιάδης, Ιωάννης	el
heal.committeeMemberName	Προβατίδης, Χριστόφορος	el
heal.academicPublisher	Εθνικό Μετσόβιο Πολυτεχνείο. Σχολή Μηχανολόγων Μηχανικών. Τομέας Μηχανολογικών Κατασκευών και Αυτομάτου Ελέγχου	el
heal.academicPublisherID	ntua
heal.numberOfPages	79 σ.	el
heal.fullTextAvailability	false