Commenced in January 2007
Paper Count: 31105
Fatigue Life Consumption for Turbine Blades-Vanes Accelerated by Erosion-Contour Modification
Abstract:A new mechanism responsible for structural life consumption due to resonant fatigue in turbine blades, or vanes, is presented and explained. A rotating blade or vane in a gas turbine can change its contour due to erosion and/or material build up, in any of these instances, the surface pressure distribution occurring on the suction and pressure sides of blades-vanes can suffer substantial modification of their pressure and temperatures envelopes and flow characteristics. Meanwhile, the relative rotation between the blade and duct vane while the pressurized gas flows and the consequent wake crossings, will induce a fluctuating thrust force or lift that will excite the blade. An actual totally used up set of vane-blade components in a HP turbine power stage in a gas turbine is analyzed. The blade suffered some material erosion mostly at the trailing edge provoking a peculiar surface pressure envelope which evolved as the relative position between the vane and the blade passed in front of each other. Interestingly preliminary modal analysis for this eroded blade indicates several natural frequencies within the aeromechanic power spectrum, moreover, the highest frequency component is 94% of one natural frequency indicating near resonant condition. Independently of other simultaneously occurring fatigue cycles (such as thermal, centrifugal stresses).
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1076326Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2256
 Han, J., Dutta, S., Ekkad, S. "Gas Turbine Heat Transfer and Cooling Technology", Taylor&Francis, New York, NY, 2000.
 Woisetschlager, J., Lang, H., Hampel, B., Gottlich, E. and Heitmeir, F. Influence of blade passing on the stator wake in a transonic turbine stage investigated by particle image velocimetry and laser vibrometry Proc. Instn Mech. Engrs Vol. 217 Part A: J. Power and Energy, 2003.
 Sondak, D. L. and Dorney, D. J. Simulation of vortex shedding in a turbine stage. J. Turbomach., 1999, 121, 428-435.
 Adami, P. and Martelli, F.. Three-dimensional unsteady investigation of HP turbine stages. Proc. IMechE Vol. 220 Part A: J. Power and Energy, 2006.
 Tofighi, M., Ali, S., Rezamahdi, N. "Failure Analysis of Gas Turbine Blades", K.N. Toosi University of Technology, Paper 120, ENG 108, Proceedings of the 2008 LAJC-IJME International Conference, Iran, 2008.
 ANSYS FLUENT 12.0 "Theory Guide"
 Maintenance manual MFT4-CID/LF Vol. 1 y Vol. 2.
 Dennis G. Zill, C├ílculo con Geometr├¡a Anal├¡tica, Editorial Iberoamericana, segunda edici├│n.
 Shih, T.-H., Liou, W. W., Shabbir. A., Yang, Z., and Zhu, J. A New k- ╬Á Eddy- Viscosity Model for High Reynolds Number Turbulent Flows - Model Development and Validation. Computers Fluids, 24(3):227- 238, 1995.
 Fern Engineering, Inc., "Gas Turbine and Combined - Cycle Capacity Enhancement", TR-102412, Generation & Storage Division, EPRI Project Manager, Palo Alto, California, October, 1993.
 Haldeman, C. W., Mathison, R. M., "Aerodynamic and Heat Flux Measurements in a Single-Stage Fully Cooled Turbine- Part I: Experimental Approach", Journal of Turbomachinery, Vol.130/021015-1, Columbus, OH., April 2008
 Cizmas, Paul and Subramanya, Ravishankar, Parallel computation of rotor/stator interaction, Westinghouse Electric Corporation and Pittsburgh Supercomputing Center, internal publication 1996.
 G├│mez-Mancilla, J., Sinou(est), Jean-Jacques, Nosov, V. R., Thouverez, F., Zambrano(est), A., "The influence of crack-imbalance orientation and orbital evolution for an extended cracked jeffcott rotor", COMPTES-RENDUS Mecanique, R.C., ISSN: 1631-0721, editorial Elsevier, Vol. 332, 2004, Diciembre 2004, pags. 955-962.
 Machorro-Lopez(est), José M., Adams, Douglas E, G├│mez-Mancilla, Julio C., Gul(est), Kamra, Identification of damaged shafts using active sensing - simulation and experimentation, journal of sound and vibration, Elsevier, Vol. 327, Noviembre 2009, pags. 368-390. ISSN 0022-460X
 G├│mez-Mancilla J., Garc├¡a illescas(est), Nosov V., Detection of steady crack growth on rota-ting shafts, Procs. 2nd International Symposium On Control And Stability Of Rotating Machinery, ISCORMA-2, Gdansk Technologic University y Bently Press. Brg, Gdansk, Polonia, Sept. 2003
 Machorro-L├│pez J.M.(est), Adams D.E., Gomez-Mancilla J.C., Crack detection of shafts in rotating machinery using active sensing with an external excitation on a bearing, Proceedings of the American Society of Mechanical Engrs, ASME, SMASIS-08, ISBN 978-7918- 3839-6, copyright 2008 ASME, paper 467, Turf Valley, Ellicott City, EEUU, 28-30 Octubre 2008.
 Adams, D. E., "Health Monitoring of Structural Materials and Components: Methods with Applications," 2007, John Wiley & Sons, Chichester, UK
 Haroon, M. and Adams, D., E., "Component-Level Damage Evolution Laws for Mechanical Damage Prognosis," 2008, American Society of Mechanical Engineering Journal of Applied Mechanics, Vol. 74(2), DOI: 10.1115/1.2793137
 Douglas E. Adams, Health Monitoring of Structural Materials and Components, Ed. John Wiley & Sons Ltd, USA 2007. ISBN 978-0- 470-03313-5