Hostname: page-component-586b7cd67f-dsjbd Total loading time: 0 Render date: 2024-11-25T05:01:27.695Z Has data issue: false hasContentIssue false
  • English
  • Français

Turbine thermomechanical modelling during excessive axial movement and overspeed

Published online by Cambridge University Press:  14 March 2019

I. Eryilmaz Open the ORCID record for I. Eryilmaz [Opens in a new window]  and
V. Pachidis
I. Eryilmaz*
Affiliation:
Cranfield University, Bedford, UK
V. Pachidis
Affiliation:
Cranfield University, Bedford, UK
*
*[email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

This manuscript discusses the numerical (finite element) and analytical modelling of structural interactions between gas turbine components in case of excessive axial movement and overspeed. Excessive axial movement, which may occur after a shaft failure, results in contact between rotating and static turbine components under high forces. These forces create friction which can act as a counter torque, potentially retarding the ‘free-rotating’ components. The study is based on a shaft failure scenario of a ‘three-shaft’, high ‘bypass’ ratio, civil ‘large-fan’ engine. Coupled analytical performance and friction methods are used as stand-alone tools to investigate the effect of rubbing between rotating and stationary components. The method is supported by ‘high-fidelity’, ‘three-dimensional’, thermomechanical finite element simulations using LS-DYNA software. The novelty of the work reported herein lies in the development of a generalised modelling approach that can produce useful engine design guidelines to minimise the terminal speed of a free running turbine after an unlocated shaft failure. The study demonstrates the advantage of using a fast analytical formulation in a design space exploration, after verifying the analytical model against finite element simulation results. The radius and the area of a stationary seal platform in the turbine assembly are changed systematically and the design space is explored in terms of turbine acceleration, turbine dislocation rate and stationary component mass. The radius of the friction interface increases due to the increasing radius of the nozzle guide vane flow path and stationary seal platform. This increases the frictional torque generated at the interface. It was found that if the axial dislocation rate of the free running turbine wheel is high, the resulting friction torque becomes more effective as an overspeed prevention mechanism. Reduced contact area results in a higher axial dislocation rate and this condition leads to a design compromise between available friction capacity, during shaft failure contact and seal platform structural integrity.

Keywords

Thermal structural FEALS-DYNAShaft failureTurbine overspeed
Type
Research Article
Information
The Aeronautical Journal , Volume 123 , Issue 1260 , February 2019 , pp. 248 - 264
Check for updates
Copyright
© Royal Aeronautical Society 2019 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. ATSB, In-flight uncontained engine failure Airbus A380-842 VH-OQA, Australian Transport Safety Bureau, Australia, 2013.Google Scholar
2. Whurr, J. Future civil aero-engine architectures and technologies, 10th ETC Conference invited speaker presentation, Finland, 15 April 2013.Google Scholar
3. TCR, Failure and root cause analysis, investigating material and component failure, TCR Engineering Services, India, 2004.Google Scholar
4. ATSB, Uncontained engine failure and air turn-back near San Francisco airport USA, Australian Transport Safety Bureau, Australia, 2012.Google Scholar
5. EASA, Certification specifications for engines, European Aviation Safety Agency, 2015, CS-E Amendment 4.Google Scholar
6. FAA, Engine and turbosupercharger rotor overspeed requirements of 14 CFR 33.27, Federal Aviation Administration, 2011.Google Scholar
7. Gonzalez, A. and Pachidis, V. On the numerical simulation of turbine blade tangling after a shaft failure, Germany, 2014, ASME GT2014-27061.Google Scholar
8. Ortiz, R., Herran, M. and Chalons, H. Blade loss studies in low pressure turbines from blade containment to controlled blade shedding, WIT Transactions on Modelling and Simulations, 2009, 48, pp 559–567.Google Scholar
9. ATSB, Uncontained engine starter failure, General Electric CF6-80E1-A3, Australian Transport Safety Bureau, Australia, 2008.Google Scholar
10. Coxhead, T.M. Stub axle, 2006, US Patent 6986637 B2.Google Scholar
11. Ferlauto, M. and Taddei, S. Reduced order modelling of full-span rotating stall for the flow control simulation of axial compressors, Proceedings of the Institution of Mech Engineers, Part A: IMechE J Power and Energy, 2015, 229, (4), pp 352–366.Google Scholar
12. Psarra, A. Gas Turbine Shaft Failure Modelling Friction and Wear Modelling of Turbines in Contact, PhD Thesis, Cranfield University, Bedford, UK, 2010.Google Scholar
13. Cendón, D., Erice, B., Gálvez, F. and Sanchez-Galvez, V. Numerical simulation of tangling in jet engine turbines, Int J Turbo Jet-Engines, 2012, 29, pp 269–282.Google Scholar
14. Hermosilla, U., Alcaraz, J. and AJA, A. Blade impact simulation against casings, ABAQUS User’s Conference, 2004.Google Scholar
15. Haake, M., Fiola, R. and Staudacher, S. Multistage compressor and turbine modeling for the prediction of the maximum turbine speed resulting from shaft breakage, ASME J Turbomach, 2010, 133, (2), pp 021022.Google Scholar
16. Bahrani, A. and Duffin, F. Frictional behavior of mild steel in friction welding, Wear, 1973, 26, (1), pp 53–74.Google Scholar
17. Bahrani, A., Healy, J. and Mcmullan, D. Analysis of frictional phenomena in friction welding of mild steel, Wear, 1975, 37, (2), pp 265–278.Google Scholar
18. Johnson, G. and Cook, W. Fracture characteristics of three metals subjected to various strains, strain rates temperatures and pressures, Engineering Fracture Mechanics, 1985, 21, (1), pp 31–48.Google Scholar
19. Gonzalez, A. Gas Turbine Shaft Over-speed/Failure Modelling. Friction and Wear Modelling of Turbines in Contact, PhD Thesis, Cranfield University, Bedford, UK, 2014.Google Scholar
20. Carslaw, H. and Jaeger, J. Conduction of heat in solids, 2nd ed, Great Britain: Oxford University Press, 1959.Google Scholar
21. Barber, J. Distribution of heat between sliding surfaces, J Mech Engineering Science, 1967, 9, (5), pp 351–354.Google Scholar
22. Soupizon, J. Device for limiting turbine overspeed in a turbomachine, 2006, US Patent 20060251506 A1.Google Scholar