Failure investigation of a Kaplan turbine blade
In this paper, an uncommon failure of a Kaplan turbine blade has been analyzed. After the monitoring system detected a sudden increase in vibration levels, the turbine was inspected. The inspection showed that a large crack occurred on one blade starting from the leading-edge side root hole. Moreove...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2019 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/133632 |
| Acceso en línea: | https://hdl.handle.net/2117/133632 https://dx.doi.org/10.1016/j.engfailanal.2019.01.056 |
| Access Level: | acceso abierto |
| Palabra clave: | Turbines--Blades Failure of a Kaplan turbine blade Turbine Kaplan Turbines hidràuliques Àrees temàtiques de la UPC::Enginyeria mecànica::Mecànica de fluids::Màquines hidràuliques i de fluids |
| Sumario: | In this paper, an uncommon failure of a Kaplan turbine blade has been analyzed. After the monitoring system detected a sudden increase in vibration levels, the turbine was inspected. The inspection showed that a large crack occurred on one blade starting from the leading-edge side root hole. Moreover, the tip of the blade was also found broken. A comprehensive analysis of the crack surfaces, broken parts and the vibration data revealed a fatigue problem probably caused by rubbing between the blade and the nearby wall. The effect of contacts on the stress distribution of the blade was investigated through a numerical model of the turbine blade. To validate this numerical model an experimental modal analysis was done on a nondamaged blade and the results showed a good agreement with the numerical results. Stress distribution analysis showed that when applying a contact force, the stress at the leading-edge root hole increases drastically. Therefore, experimental evidences as well as numerical simulations confirm that the crack occurred due to rubbing between the blade tip and the nearby wall. |
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