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Transient dynamic finite element modelling of flexible rotor systems with nonlinear fluid film bearings and faults
Dissertation (MEng)--University of Pretoria, 2015.
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| Format: | Thesis |
| Language: | English |
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University of Pretoria
2015
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| _version_ | 1867613536617758720 |
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| access_status_str | Open Access |
| author2 | Heyns, P.S. (Philippus Stephanus) |
| author_browse | Heyns, P.S. (Philippus Stephanus) |
| author_facet | Heyns, P.S. (Philippus Stephanus) |
| collection | Thesis |
| dc_rights_str_mv | © 2015 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Dissertation (MEng)--University of Pretoria, 2015. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/43912 |
| institution | University of Pretoria (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:37:42.843Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2015 |
| publishDateRange | 2015 |
| publishDateSort | 2015 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/43912 Transient dynamic finite element modelling of flexible rotor systems with nonlinear fluid film bearings and faults Heyns, P.S. (Philippus Stephanus) Oberholster, Abraham Johannes Krüger, Armand Mechanical Engineering Mechanical Vibrations Rotor Dynamics Finite Element Analysis UCTD Engineering, built environment and information technology theses SDG-09 SDG-09: Industry, innovation and infrastructure Engineering, built environment and information technology theses SDG-07 SDG-07: Affordable and clean energy Engineering, built environment and information technology theses SDG-12 SDG-12: Responsible consumption and production Dissertation (MEng)--University of Pretoria, 2015. This dissertation forms part of a research project assigned to the University of Pretoria by Eskom (the primary electricity utility in South Africa). The project aims to address, amongst others, the limitations imposed by shaft runout on the usable frequency range of diagnostic data measured by eddy current proximity probes on turbogenerator shafts. This research includes an experimental investigation into the effects of artificially induced faults on a laboratory-scale rotor system, the development and analysis of a mathematical (numerical) model of this rotor system and the development of data processing techniques (including artificial intelligence) to determine the rotor’s condition, faults and diagnostic signal parameters from both the experimental and numerical results. Furthermore, a methodology is to be developed to perform runout compensation in an unsupervised manner. These techniques are then to be implemented for proximity probe vibration data measured on turbogenerators. As part of the research project, this dissertation specifically focuses on the development and rotor dynamic analysis of numerical (finite element) models of the experimental (laboratory-scale) rotor system (using finite element software MSC.Nastran), including gyroscopic effects, a nonlinear force model for the hydrodynamic journal bearing of the rotor system (capable of capturing oil whirl and oil whip instabilities) as well as simulated faults (such as unbalance and rotor-stator rubbing). Since MSC.Nastran does not have a built-in nonlinear hydrodynamic journal bearing model, a custom model of such a bearing was developed and incorporated into the finite element solver, further expanding its already powerful rotor dynamic modelling capabilities. Rotor dynamic analyses performed include the calculation of critical speeds (synchronous complex modes analysis), Campbell diagrams (asynchronous complex modes analysis), steady state frequency response due to unbalance (synchronous frequency response analysis) and nonlinear transient response during rotor run-up. Amongst others, this dissertation explores the seemingly largely unexplored/undocumented capability of finite element software MSC.Nastran to perform rotor dynamic analyses using rotor models constructed with three-dimensional elements. Software (MATLAB code) was also developed to perform post-processing of the simulation results as well as signal processing for investigating the spectral content of transient results. The support structure of the laboratory-scale rotor system was experimentally characterised and an experimental modal analysis was performed on the rotor (excluding its support structure) and its results used to update the finite element rotor models. The transient dynamic response of the experimental rotor system during run-up due to unbalance and rubbing was also analysed in order to validate the developed numerical rotor system models. The numerical results are found to be in good agreement with the experimental results. mi2025 Mechanical and Aeronautical Engineering Unrestricted SDG-09: Industry, innovation and infrastructure SDG-07: Affordable and clean energy SDG-12: Responsible consumption and production 2015-03-10T07:00:44Z 2015-03-10T07:00:44Z 2015-04-23 2015 Dissertation Krüger, A 2015, Transient dynamic finite element modelling of flexible rotor systems with nonlinear fluid film bearings and faults, MEng dissertation, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/43912> S2015 http://hdl.handle.net/2263/43912 en © 2015 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria |
| spellingShingle | Mechanical Engineering Mechanical Vibrations Rotor Dynamics Finite Element Analysis UCTD Engineering, built environment and information technology theses SDG-09 SDG-09: Industry, innovation and infrastructure Engineering, built environment and information technology theses SDG-07 SDG-07: Affordable and clean energy Engineering, built environment and information technology theses SDG-12 SDG-12: Responsible consumption and production Transient dynamic finite element modelling of flexible rotor systems with nonlinear fluid film bearings and faults |
| title | Transient dynamic finite element modelling of flexible rotor systems with nonlinear fluid film bearings and faults |
| title_full | Transient dynamic finite element modelling of flexible rotor systems with nonlinear fluid film bearings and faults |
| title_fullStr | Transient dynamic finite element modelling of flexible rotor systems with nonlinear fluid film bearings and faults |
| title_full_unstemmed | Transient dynamic finite element modelling of flexible rotor systems with nonlinear fluid film bearings and faults |
| title_short | Transient dynamic finite element modelling of flexible rotor systems with nonlinear fluid film bearings and faults |
| title_sort | transient dynamic finite element modelling of flexible rotor systems with nonlinear fluid film bearings and faults |
| topic | Mechanical Engineering Mechanical Vibrations Rotor Dynamics Finite Element Analysis UCTD Engineering, built environment and information technology theses SDG-09 SDG-09: Industry, innovation and infrastructure Engineering, built environment and information technology theses SDG-07 SDG-07: Affordable and clean energy Engineering, built environment and information technology theses SDG-12 SDG-12: Responsible consumption and production |
| url | http://hdl.handle.net/2263/43912 |