A Numerical Analysis of the Nonlinear Dynamics of Shimmed Conical Gas Foil Bearings
Conical gas foil bearings (CGFBs) have the potential to halve the number of necessary bearings in a conventional rotor system supported by gas foil bearings. Transient simulations of gas foil journal bearings and gas foil thrust bearings have proven their necessity to accurately predict the safe ope...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-05-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/13/10/5859 |
| _version_ | 1797601242405404672 |
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| author | Marian Sarrazin Robert Liebich |
| author_facet | Marian Sarrazin Robert Liebich |
| author_sort | Marian Sarrazin |
| collection | DOAJ |
| description | Conical gas foil bearings (CGFBs) have the potential to halve the number of necessary bearings in a conventional rotor system supported by gas foil bearings. Transient simulations of gas foil journal bearings and gas foil thrust bearings have proven their necessity to accurately predict the safe operating range of such bearings. This work presents the first transient model able to simulate the three-dimensional dynamics of CGFBs. The static behaviour of a single CGFB with a uniform bearing clearance is compared to a CGFB modified by thin metal shims and the resulting advantages of shimmed CGFBs are discussed. An investigation of the linear stability behaviour shows that the axial load of the bearing determines the stability of the equilibrium position. Furthermore, three transient simulations demonstrate the capability of the presented model to describe the nonlinear dynamics of a shimmed CGFB such as the occurrence of stable limit cycles and self-excited sub- and super-synchronous vibrations with and without a rotor unbalance. Additionally, waterfall diagrams are used to investigate the frequency response for different rotational speeds. The novel findings of this work are the importance of a non-uniform bearing clearance for the functionality of a CGFB and the identification of the axial force as a critical factor in maintaining bearing stability. These findings are specific to CGFBs and have not been discussed or mentioned in previous works. |
| first_indexed | 2024-03-11T03:59:21Z |
| format | Article |
| id | doaj.art-2220ca1d85854db4a343a0361b35bc2b |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-11T03:59:21Z |
| publishDate | 2023-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-2220ca1d85854db4a343a0361b35bc2b2023-11-18T00:16:47ZengMDPI AGApplied Sciences2076-34172023-05-011310585910.3390/app13105859A Numerical Analysis of the Nonlinear Dynamics of Shimmed Conical Gas Foil BearingsMarian Sarrazin0Robert Liebich1Department for Engineering Design and Product Reliability, Technische Universität Berlin (TU Berlin), Str. d. 17. Juni 135, 10623 Berlin, GermanyDepartment for Engineering Design and Product Reliability, Technische Universität Berlin (TU Berlin), Str. d. 17. Juni 135, 10623 Berlin, GermanyConical gas foil bearings (CGFBs) have the potential to halve the number of necessary bearings in a conventional rotor system supported by gas foil bearings. Transient simulations of gas foil journal bearings and gas foil thrust bearings have proven their necessity to accurately predict the safe operating range of such bearings. This work presents the first transient model able to simulate the three-dimensional dynamics of CGFBs. The static behaviour of a single CGFB with a uniform bearing clearance is compared to a CGFB modified by thin metal shims and the resulting advantages of shimmed CGFBs are discussed. An investigation of the linear stability behaviour shows that the axial load of the bearing determines the stability of the equilibrium position. Furthermore, three transient simulations demonstrate the capability of the presented model to describe the nonlinear dynamics of a shimmed CGFB such as the occurrence of stable limit cycles and self-excited sub- and super-synchronous vibrations with and without a rotor unbalance. Additionally, waterfall diagrams are used to investigate the frequency response for different rotational speeds. The novel findings of this work are the importance of a non-uniform bearing clearance for the functionality of a CGFB and the identification of the axial force as a critical factor in maintaining bearing stability. These findings are specific to CGFBs and have not been discussed or mentioned in previous works.https://www.mdpi.com/2076-3417/13/10/5859conical gas foil bearingtransient simulationnonlinear dynamicsshimming |
| spellingShingle | Marian Sarrazin Robert Liebich A Numerical Analysis of the Nonlinear Dynamics of Shimmed Conical Gas Foil Bearings Applied Sciences conical gas foil bearing transient simulation nonlinear dynamics shimming |
| title | A Numerical Analysis of the Nonlinear Dynamics of Shimmed Conical Gas Foil Bearings |
| title_full | A Numerical Analysis of the Nonlinear Dynamics of Shimmed Conical Gas Foil Bearings |
| title_fullStr | A Numerical Analysis of the Nonlinear Dynamics of Shimmed Conical Gas Foil Bearings |
| title_full_unstemmed | A Numerical Analysis of the Nonlinear Dynamics of Shimmed Conical Gas Foil Bearings |
| title_short | A Numerical Analysis of the Nonlinear Dynamics of Shimmed Conical Gas Foil Bearings |
| title_sort | numerical analysis of the nonlinear dynamics of shimmed conical gas foil bearings |
| topic | conical gas foil bearing transient simulation nonlinear dynamics shimming |
| url | https://www.mdpi.com/2076-3417/13/10/5859 |
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