Analysis of the Instability Phenomena Caused by Steam in High-Pressure Turbines
Instability phenomena in steam turbines may happen as a consequence of certain characteristics of the steam flow as well as of the mechanical and geometrical properties of the seals. This phenomenon can be modeled and the raise of the steam flow and pressure causes the increase of the cross coupled...
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| Format: | Article |
| Language: | English |
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Wiley
2011-01-01
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| Series: | Shock and Vibration |
| Online Access: | http://dx.doi.org/10.3233/SAV-2010-0575 |
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| _version_ | 1832548914995134464 |
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| author | Paolo Pennacchi Andrea Vania |
| author_facet | Paolo Pennacchi Andrea Vania |
| author_sort | Paolo Pennacchi |
| collection | DOAJ |
| description | Instability phenomena in steam turbines may happen as a consequence of certain characteristics of the steam flow as well as of the mechanical and geometrical properties of the seals. This phenomenon can be modeled and the raise of the steam flow and pressure causes the increase of the cross coupled coefficients used to model the seal stiffness. As a consequence, the eigenvalues and eigenmodes of the mathematical model of the machine change. The real part of the eigenvalue associated with the first flexural normal mode of the turbine shaft may become positive causing the conditions for unstable vibrations. The original contribution of the paper is the application of a model-based analysis of the dynamic behavior of a large power unit, affected by steam-whirl instability phenomena. The model proposed by the authors allows studying successfully the experimental case. The threshold level of the steam flow that causes instability conditions is analyzed and used to define the stability margin of the power unit. |
| format | Article |
| id | doaj-art-bd403fbb72ad4c5790d615814f3d2fd7 |
| institution | Kabale University |
| issn | 1070-9622 1875-9203 |
| language | English |
| publishDate | 2011-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Shock and Vibration |
| spelling | doaj-art-bd403fbb72ad4c5790d615814f3d2fd72025-02-03T06:12:40ZengWileyShock and Vibration1070-96221875-92032011-01-0118459361210.3233/SAV-2010-0575Analysis of the Instability Phenomena Caused by Steam in High-Pressure TurbinesPaolo Pennacchi0Andrea Vania1Politecnico di Milano, Department of Mechanical Engineering, Via La Masa 1, 20156 Milan, ItalyPolitecnico di Milano, Department of Mechanical Engineering, Via La Masa 1, 20156 Milan, ItalyInstability phenomena in steam turbines may happen as a consequence of certain characteristics of the steam flow as well as of the mechanical and geometrical properties of the seals. This phenomenon can be modeled and the raise of the steam flow and pressure causes the increase of the cross coupled coefficients used to model the seal stiffness. As a consequence, the eigenvalues and eigenmodes of the mathematical model of the machine change. The real part of the eigenvalue associated with the first flexural normal mode of the turbine shaft may become positive causing the conditions for unstable vibrations. The original contribution of the paper is the application of a model-based analysis of the dynamic behavior of a large power unit, affected by steam-whirl instability phenomena. The model proposed by the authors allows studying successfully the experimental case. The threshold level of the steam flow that causes instability conditions is analyzed and used to define the stability margin of the power unit.http://dx.doi.org/10.3233/SAV-2010-0575 |
| spellingShingle | Paolo Pennacchi Andrea Vania Analysis of the Instability Phenomena Caused by Steam in High-Pressure Turbines Shock and Vibration |
| title | Analysis of the Instability Phenomena Caused by Steam in High-Pressure Turbines |
| title_full | Analysis of the Instability Phenomena Caused by Steam in High-Pressure Turbines |
| title_fullStr | Analysis of the Instability Phenomena Caused by Steam in High-Pressure Turbines |
| title_full_unstemmed | Analysis of the Instability Phenomena Caused by Steam in High-Pressure Turbines |
| title_short | Analysis of the Instability Phenomena Caused by Steam in High-Pressure Turbines |
| title_sort | analysis of the instability phenomena caused by steam in high pressure turbines |
| url | http://dx.doi.org/10.3233/SAV-2010-0575 |
| work_keys_str_mv | AT paolopennacchi analysisoftheinstabilityphenomenacausedbysteaminhighpressureturbines AT andreavania analysisoftheinstabilityphenomenacausedbysteaminhighpressureturbines |