Gas turbine blade natural frequency measurement using external casing vibrations
Currently tip timing methods are the pseudo industry standard for measuring Gas Turbine blade vibration. The physical placement of tip timing probes is however reasonably prohibitive due to the high pressure/temperature environment of a turbine. A simpler method of sensor setup would be through the...
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| Format: | Conference Paper |
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MFPT
2013
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| Online Access: | http://hdl.handle.net/20.500.11937/12187 |
| _version_ | 1848748008194179072 |
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| author | Ratz, Johannes Forbes, Gareth Randall, Robert |
| author2 | MFPT |
| author_facet | MFPT Ratz, Johannes Forbes, Gareth Randall, Robert |
| author_sort | Ratz, Johannes |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Currently tip timing methods are the pseudo industry standard for measuring Gas Turbine blade vibration. The physical placement of tip timing probes is however reasonably prohibitive due to the high pressure/temperature environment of a turbine. A simpler method of sensor setup would be through the use of externally mounted accelerometers to measure the casing vibration response and relate this back to the internal blade vibration.The vibration of a gas turbine casing is driven by the strong rotating pressure which develops around the rotating blade stages. The oscillating motion of the rotor blades phase modulates this pressure signal. An analytical formulation of the internal pressure signal is developed in this paper. The effects of blade motion on this internal pressure signal is then investigated as the speed of the engine is increased/decreased such that the driving frequency traverses a rotor blade natural frequency. Experimental measurements on a simplified test turbine are presented comparing the results of the analytical internal pressure signal along with results of the measured casing vibration during engine run up/down. It is shown that the spectrum of the internal pressure and casing vibration signal contains information which can be used to estimate the rotor blade natural frequencies. |
| first_indexed | 2025-11-14T06:58:12Z |
| format | Conference Paper |
| id | curtin-20.500.11937-12187 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T06:58:12Z |
| publishDate | 2013 |
| publisher | MFPT |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-121872017-01-30T11:29:12Z Gas turbine blade natural frequency measurement using external casing vibrations Ratz, Johannes Forbes, Gareth Randall, Robert MFPT internal pressure Blade vibration gas turbines casing vibration Currently tip timing methods are the pseudo industry standard for measuring Gas Turbine blade vibration. The physical placement of tip timing probes is however reasonably prohibitive due to the high pressure/temperature environment of a turbine. A simpler method of sensor setup would be through the use of externally mounted accelerometers to measure the casing vibration response and relate this back to the internal blade vibration.The vibration of a gas turbine casing is driven by the strong rotating pressure which develops around the rotating blade stages. The oscillating motion of the rotor blades phase modulates this pressure signal. An analytical formulation of the internal pressure signal is developed in this paper. The effects of blade motion on this internal pressure signal is then investigated as the speed of the engine is increased/decreased such that the driving frequency traverses a rotor blade natural frequency. Experimental measurements on a simplified test turbine are presented comparing the results of the analytical internal pressure signal along with results of the measured casing vibration during engine run up/down. It is shown that the spectrum of the internal pressure and casing vibration signal contains information which can be used to estimate the rotor blade natural frequencies. 2013 Conference Paper http://hdl.handle.net/20.500.11937/12187 MFPT fulltext |
| spellingShingle | internal pressure Blade vibration gas turbines casing vibration Ratz, Johannes Forbes, Gareth Randall, Robert Gas turbine blade natural frequency measurement using external casing vibrations |
| title | Gas turbine blade natural frequency measurement using external casing vibrations |
| title_full | Gas turbine blade natural frequency measurement using external casing vibrations |
| title_fullStr | Gas turbine blade natural frequency measurement using external casing vibrations |
| title_full_unstemmed | Gas turbine blade natural frequency measurement using external casing vibrations |
| title_short | Gas turbine blade natural frequency measurement using external casing vibrations |
| title_sort | gas turbine blade natural frequency measurement using external casing vibrations |
| topic | internal pressure Blade vibration gas turbines casing vibration |
| url | http://hdl.handle.net/20.500.11937/12187 |