Research Papers: Gas Turbines: Controls, Diagnostics, and Instrumentation

Optimization of Aero Gas Turbine Maintenance Using Advanced Simulation and Diagnostic Methods

[+] Author and Article Information
Joern Kraft

Engine Overhaul Department,
Lufthansa Technik AG,
Weg beim Jäger 193,
Hamburg 22335, Germany
e-mail: Joern.Kraft@lht.dlh.de

Vishal Sethi

Department of Power and Propulsion,
Cranfield University,
Cranfield, Bedfordshire MK43 0AL, UK
e-mail: V.Sethi@cranfield.ac.uk

Riti Singh

Department of Power and Propulsion,
Cranfield University,
Cranfield, Bedfordshire MK43 0AL, UK
e-mail: R.Singh@cranfield.ac.uk

Contributed by the Controls, Diagnostics and Instrumentation Committee of ASME for publication in the JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER. Manuscript received May 7, 2013; final manuscript received March 31, 2014; published online May 16, 2014. Assoc. Editor: Allan Volponi.

J. Eng. Gas Turbines Power 136(11), 111601 (May 16, 2014) (10 pages) Paper No: GTP-13-1134; doi: 10.1115/1.4027356 History: Received May 07, 2013; Revised March 31, 2014

Engine maintenance costs are a major contributor to the direct operating costs of aircraft. Therefore, the minimization of engine maintenance costs per flight-hour is a key aspect for airlines to operate successfully under challenging market conditions. Minimization can be achieved by increasing the on-wing time or by reducing the shop-visit costs. Combining both provides optimum results and can only be achieved by thorough understanding of the engine. In the past, maintenance optimization was mainly an experience-based process. In this work, a novel analytical approach is presented to optimize the maintenance of commercial turbofan engines. A real engine fleet of more than 100 long-haul engines is used to demonstrate the application. The combination of advanced diagnostic and simulation methods with classical hardware-based failure analysis enables linking of overall engine performance with detailed hardware condition and, thus, an effective optimization of the overall maintenance process.

Copyright © 2014 by ASME
Topics: Maintenance , Engines
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Visser, W. P. J., Kogenhop, O., and Oostveen, M., 2006, “A Generic Approach for Gas Turbine Adaptive Modeling,,” ASME J. Eng. Gas Turb. Power, 128(1), pp. 13–19. [CrossRef]
Verbist, M. L., Visser, W. P. J, van Buijtenen, J. P., and Duivis, R., 2011, “Gas Path Analysis on KLM In-Flight Engine Data,” ASME Paper No. GT2011-45625. [CrossRef]
Kurzke, J., 2005, “How to Create a Performance Model of a Gas Turbine From a Limited Amount of Information,” ASME Paper No. GT2005-68536. [CrossRef]
Kurzke, J., 2008, “The Importance of Component Maps for Gas Turbine Performance Simulations,” 12th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery (ISROMAC-12), Honolulu, HI, February 17–22.
Li, Y. G., Marinai, L., Gatto, E. L., Pachidis, V., and Piliddis, P., 2009, “Multiple-Point Adaptive Performance Simulation Tuned to Aero Engine Test-Bed Data,” J. Propul. Power, 25(3), pp. 635–641. [CrossRef]
Pachidis, V., Pilidis, P., Guindeuil, G., Kalfas, A., and Templalexis, I., 2005, “A Partially Integrated Approach to Component Zooming Using Computational Fluid Dynamics,” ASME Paper No. GT2005-68457. [CrossRef]
Pachidis, V., Pilidis, P., Talhouarn, F., Kalfas, A., and Templalexis, I., 2006, “A Fully Integrated Approach to Component Zooming Using Computational Fluid Dynamics,” ASME J. Eng. Gas Turb. Power, 128(3), pp. 579–584. [CrossRef]
Pachidis, V.Pilidis, P.Marinai, L.TemplalexisI., 2007, “Towards a Full Two Dimensional Gas Turbine Performance Simulator,” Aeronaut. J., 111(1121), pp. 433-442.
Pachidis, V., Pilidis, P., Texeira, J., and Templalexis, I., 2007, “A Comparison of Component Zooming Simulation Strategies Using Streamline Curvature,” Proc. IMechE, 221(1), pp. 1–15. [CrossRef]
Lytle, J. K., 1999, “The Numerical Propulsion System Simulation: A Multidisciplinary Design System for Aerospace Vehicles,” NASA/TM–1999-209194.
VeresJ. P., 2002, “Overview of High-Fidelity Modeling Activities in the Numerical Propulsion System Simulation (NPSS) Project,” NASA/TM–2002-211351.
Hall, E. J., Lynn, S. R., Heidegger, N. J., and Delany, R. A., 1998, “Energy Efficient Engine Low Pressure Subsystem Flow Analysis,” NASA/CR–1998-206597.
Hall, E. J., Delany, R. A., Lynn, S. R., and Veres, J. P., 1998, “Low Pressure Subsystem Flow Analysis,” NASA/TM–1998-208402.
Reed, J. A., Turner, M. G., Norris, A., and Veres, J. P., 2003, “Towards an Automated Full-Turbofan Engine Numerical Simulation,” NASA/TM–2003-212494.
Turner, M. G., Ryder, R., Reed, J. A., and Veres, J. P., 2004, “Multi-Fidelity Simulation of a Turbofan Engine With Results Zoomed Into Mini-Maps for a Zero-D Cycle Simulation,” ASME Paper No. GT2004-53956. [CrossRef]
Dubitsky, O., Wiedermann, A., Nakano, T., and Perera, J., 2003, “The Reduced Order Through-Flow Modeling of Axial Turbomachinery,” International Gas Turbine Congress (IGTC2003Tokyo), Tokyo, Japan, November 2–7, Paper No. TS-052.
Koch, C. C., and SmithL. H., 1976, “Loss Sources and Magnitudes in Axial-Flow Compressors,” ASME J. Eng. Gas Turb. Power, 98(3), pp. 411–424. [CrossRef]
Koch, C. C., 1981, “Stalling Pressure Rise Capability of Axial Flow Compressor Stages,” ASME J. Eng. Gas Turb. Power, 103(4), pp. 645–656. [CrossRef]
Ainley, D. G., and Mathieson, G. C. R., 1951, “A Method of Performance Estimation for Axial-Flow Turbines,” British Aeronautical Research Council, London, Paper No. R&M 2974.
Dunham, J., and Came, P. M.1970, “Improvements to the Ainley-Mathieson Method of Turbine Performance Prediction,” ASME J. Eng. Gas Turb. Power, 92(3), pp. 252–256. [CrossRef]
Kacker, S. C., and Okapuu, U., 1982, “A Mean Line Prediction Method for Axial Flow Turbine Efficiency,” ASME J. Eng. Gas Turb. Power, 104(1), pp. 111–119. [CrossRef]
Li, Y. G., 2002, “Performance-Analysis-Based Gas Turbine Diagnostics: A Review,” Proc. IMechE J. Power Energy, 216(5), pp. 363–377. [CrossRef]
Bauer, M., 2005, “Modulares Leistungsberechnungsverfahren zur automatisierten modellbasierten Leistungsanalyse”. Promotion Institut für Luftfahrtantriebe der Universität Stuttgart, Stuttgart, Germany.
Bauer, M., and Staudacher, S., 2008, “Fully Automated Model-Based Performance Analysis Procedure for On-Line and Off-Line Applications”. ASME J. Turbomach., 130(1), p. 011007. [CrossRef]


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Fig. 1

Thermodynamic zooming model of the engine

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Fig. 2

Evaluations of parts-performance contribution

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Fig. 3

HPC modifier measured on engines A to F plotted in fault-influence-diagram

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Fig. 4

HPC blade tip-rub (curling): mid stages of engine F

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Fig. 5

HPC blade leading edge blunting: forward stages, engine C, left: overview, right-upper: LE cross section, right-lower: micrograph LE

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Fig. 6

Corrected δ engine EGT versus test-cell LPT exit temperature T55

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Fig. 7

Analysis results of engine A analysis run 1 and run 2

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Fig. 8

Process of work-scope prediction and selection

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Fig. 10

Predicted (minimum and average performance restoration) and actual effect of work scope on module parameters

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Fig. 11

Comparison of analysis results for run 2 and run 3

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Fig. 9

Predicted (minimum and average performance restoration) and actual effect of work scope on engine main parameters

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Fig. 12

Improved predicted and actual effect of work scope on engine main parameters (original prediction for comparison)

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Fig. 13

Improved predicted and actual effect of work scope on module parameters (original prediction for comparison)

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Fig. 14

Comparison of EGT-margin pre and post improvements initiated by the project

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Fig. 15

On-wing EGT-margin trend for pre and post new maintenance concept engines



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