scholarly journals An Adaptive Model-Based Framework for Prognostics of Gas Path Faults in Aircraft Gas Turbine Engines

2019 ◽  
Vol 10 (2) ◽  
Author(s):  
Ogechukwu Alozie ◽  
Yi-Guang Li ◽  
Xin Wu ◽  
Xingchao Shong ◽  
Wencheng Ren
Keyword(s):  
Gas Turbine ◽  
Fault Isolation ◽  
Performance Model ◽  
Remaining Useful Life ◽  
Operating Conditions ◽  
Sensor Data ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Degradation Models ◽  
Useful Life

This paper presents an adaptive framework for prognostics in civil aero gas turbine engines, which incorporates both performance and degradation models, to predict the remaining useful life of the engine components that fail predominantly by gradual deterioration over time. Sparse information about the engine configuration is used to adapt a performance model, which serves as a baseline for implementing optimum sensor selection, operating data correction, fault isolation, noise reduction and component health diagnostics using nonlinear Gas Path Analysis (GPA). Degradation models, which describe the progression of faults until failure, are then applied to the diagnosed component health indices from previous run-to-failure cases. These models constitute a training library from which fitness evaluation to the current test case is done. The final remaining useful life (RUL) prediction is obtained as a weighted sum of individually evaluated RULs for each training case. This approach is validated using dataset generated by the Commercial Modular Aero-Propulsion System Simulation (CMAPSS) software, which comprises both training and testing instances of run-to-failure sensor data for a turbofan engine, some of which are obtained at different operating conditions and for multiple fault modes. The results demonstrate the capability of improved prognostics of faults in aircraft engine turbomachinery using models of system behavior, with continuous health monitoring data.

A Gas Path Diagnostic and Prognostic Approach for Gas Turbine Applications

2007 ◽  
Author(s):  
Y. G. Li ◽  
P. Nilkitsaranont
Keyword(s):  
Gas Turbine ◽  
Engine Performance ◽  
Health Condition ◽  
Remaining Useful Life ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Major Overhaul ◽  
Useful Life ◽  
Engine Reliability ◽  
Over Time

Gas turbine engines experience degradation over time that cause great concern to gas turbine users on engine reliability, availability and operating costs. It has been realized in recent years that gas turbine diagnostics and prognostics is one of the key technologies to enable the move from time-scheduled maintenance to condition-based maintenance in order to improve engine reliability and availability and reduce life cycle costs. The objective of this paper is to introduce a systematic diagnostic and prognostic approach to assess the health condition and estimate the remaining useful life of gas turbine engines before their next major overhaul. A non-linear Gas Path Analysis (GPA) approach is used to assess engine performance degradation with the confidence measured by a GPA Index. A combined regression techniques, including both linear and quadratic models, is proposed to predict the remaining useful life of gas turbine engines. A statistic “Compatibility Check” is used to determine the switch point from linear regression to quadratic regression. The developed diagnostic and prognostic approach has been applied to a model gas turbine engine similar to Rolls-Royce Industrial AVON 1535 implemented with compressor degradation over time. The analysis shows that the developed diagnostic and prognostic approach has great potential to provide an estimation of engine remaining useful life before next major overhaul for gas turbine engines experiencing a typical slow degradation.

Fuel Flexibility in LM2500 and LM6000 Dry Low Emission Engines

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
John Blouch ◽  
Hejie Li ◽  
Mark Mueller ◽  
Richard Hook
Keyword(s):  
Gas Turbine ◽  
Operating Conditions ◽  
Inert Gases ◽  
Effect Of Temperature ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Kinetics Analysis ◽  
Fuel Flexibility ◽  
Low Emission ◽  
Commercial Operation

The LM2500 and LM6000 dry-low-emissions aeroderivative gas turbine engines have been in commercial service for 15 years and have accumulated nearly 10 × 106 hours of commercial operation. The majority of these engines utilize pipeline quality natural gas predominantly comprised of methane. There is; however, increasing interest in nonstandard fuels that contain varying levels of higher hydrocarbon species and/or inert gases. This paper reports on the demonstrated operability of LM2500 and LM6000 DLE engines with nonstandard fuels. In particular, rig tests at engine conditions were performed to demonstrate the robustness of the dual-annular counter-rotating swirlers premixer design, relative to flameholding with fuels containing high ethane, propane, and N2 concentrations. These experiments, which test the ability of the hardware to shed a flame introduced into the premixing region, have been used to expand the quoting limits for LM2500 and LM6000 gas turbine engines to elevated C2+ levels. In addition, chemical kinetics analysis was performed to understand the effect of temperature, pressure, and fuel compositions on flameholding. Test data for different fuels and operating conditions were successfully correlated with Damkohler number.

Fuel Flexibility in LM2500 and LM6000 Dry Low Emission Engines

2011 ◽  
Author(s):  
John Blouch ◽  
Hejie Li ◽  
Mark Mueller ◽  
Richard Hook
Keyword(s):  
Gas Turbine ◽  
Operating Conditions ◽  
Inert Gases ◽  
Effect Of Temperature ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Kinetics Analysis ◽  
Fuel Flexibility ◽  
Low Emission ◽  
Commercial Operation

The LM2500 and LM6000 dry-low-emissions (DLE) aeroderivative gas turbine engines have been in commercial service for 15 years and have accumulated nearly 10 million hours of commercial operation. The majority of these engines utilize pipeline quality natural gas predominantly comprised of methane. There is, however, increasing interest in nonstandard fuels that contain varying levels of higher hydrocarbon species and/or inert gases. This paper reports on the demonstrated operability of LM2500 and LM6000 DLE engines with nonstandard fuels. In particular, rig tests at engine conditions were performed to demonstrate the robustness of the dual-annular counter-rotating swirlers (DACRS) premixer design, relative to flameholding with fuels containing high ethane, propane, and N2 concentrations. These experiments, which test the ability of the hardware to shed a flame introduced into the premixing region, have been used to expand the quoting limits for LM2500 and LM6000 gas turbine engines to elevated C2+ levels. In addition, chemical kinetics analysis was performed to understand the effect of temperature, pressure, and fuel compositions on flameholding. Test data for different fuels and operating conditions were successfully correlated with Damkohler number.

scholarly journals Approaches to the Prevaporized-Premixed Combustor Concept for Gas Turbines

1975 ◽  
Author(s):  
L. J. Spadaccini ◽  
E. J. Szetela
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Bluff Body ◽  
Porous Plate ◽  
Operating Conditions ◽  
Fuel Oil ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Operational Conditions ◽  
Lean Combustion

An experimental investigation was performed to evaluate a combustor concept which is applicable to gas turbine engines and is believed to offer valuable pollution control advantages relative to the conventional liquid-fuel-spray approach. It involves fuel prevaporization, premixing and lean combustion and may be applied to the design of combustors for aircraft, industrial or automotive powerplants. Two types of bluff-body flameholders, viz. porous-plate and drilled-plate, were evaluated for use as flame stabilizers within the combustor. Tests were conducted under sets of steady-state operational conditions corresponding, respectively, to applications in a low-pressure regenerative-cycle and high-pressure nonregenerative-cycle automobile gas turbine engines. The data acquired can be used to design gas turbine combustors having predicted performance characteristics which are better than those required to meet the most stringent automobile emissions regulations of the Federal “Clean Air Act.” Fuel prevaporization can be accomplished either externally, prior to admission into the engine airstream, or internally by the airstream itself. In support of the prevaporization concept, the feasibility of vaporizing No 2 fuel oil in a heat exchanger which is external to the engine was investigated. Tests conducted at representative operating conditions indicated that a deposit of 0.01 0-in. thickness was collected on the vaporizer wall after 50 hr of operation. A much shorter period of cleaning with hot air was sufficient to remove the deposit.

Prediction of CO Emission Index for Aviation Gas Turbine Combustor Using Flamelet Generated Manifold Combustion Model

2021 ◽  
Author(s):  
Saurabh Patwardhan ◽  
Pravin Nakod ◽  
Stefano Orsino ◽  
Rakesh Yadav ◽  
Fang Xu ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Liquid Fuel ◽  
Operating Conditions ◽  
Turbine Engines ◽  
Combustion Model ◽  
Gas Turbine Engines ◽  
Gas Turbine Combustor ◽  
Flamelet Generated Manifold ◽  
Emission Index ◽  
Co Emission

Abstract Carbon monoxide (CO) has been identified as one of the regulated pollutants and gas turbine manufacturers target to reduce the CO emission from their gas turbine engines. CO forms primarily when carbonous fuels are not burnt completely, or products of combustion are quenched before completing the combustion. Numerical simulations are effective tools that allow a better understanding of the mechanisms of CO formation in gas turbine engines and are useful in evaluating the effect of different parameters like swirl, fuel atomization, mixing etc. on the overall CO emission for different engine conditions like idle, cruise, approach and take off. In this paper, a thorough assessment of flamelet generated manifold (FGM) combustion model is carried out to predict the qualitative variation and magnitude of CO emission index with the different configurations of a Honeywell test combustor operating with liquid fuel under idle condition, which is the more critical engine condition for CO emission. The different designs of the test combustor are configured in such a way that they yield different levels of CO and hence are ideal to test the accuracy of the combustion model. Large eddy simulation (LES) method is used for capturing the turbulence accurately along with the FGM combustion model that is computationally economical compared to the detailed/reduced chemistry modeling using finite rate combustion model. Liquid fuel spray breakup is modeled using stochastic secondary droplet (SSD) model. Four different configurations of the aviation gas turbine combustor are studied in this work referring to earlier work by Xu et al. [1]. It is shown that the FGM model can predict CO trends accurately. The other global parameters like exit temperature, NOx emissions, pattern factor also show reasonable agreement with the test data. The sensitivity of the CO prediction to the liquid fuel droplet breakup model parameters is also studied in this work. Although the trend of CO variation is captured for different values of breakup parameters, the absolute magnitude of CO emission index differs significantly with the change in the values of breakup parameters suggesting that the spray has a larger impact on the quantitative prediction of CO emission. An accurate prediction of CO trends at idle conditions using FGM model extends the applicability of FGM model to predict different engine operating conditions for different performance criteria accurately.

Resultant Benefits of Standardized Overhaul Packages for LM2500 Propulsion Gas Turbine Engines in U.S. Navy Applications

2004 ◽  
Author(s):  
Matthew J. Driscoll ◽  
Joseph Picozzi
Keyword(s):  
Gas Turbine ◽  
Condition Based Maintenance ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
General Electric ◽  
Turbine Engine ◽  
Gas Generators ◽  
Useful Life ◽  
And Performance ◽  
Unites States

This paper discusses the Unites States Navy’s program to standardize repair and overhaul packages/workscopes for their LM2500 propulsion gas turbine engines. The General Electric LM2500 gas turbine engine is utilized for main propulsion aboard the Navy’s newest surface combatants including the FFG 7, DD 963, CG 47 and DDG 51 class ships. The Navy employs a condition based maintenance philosophy for its fleet of 450 LM2500 engines; removing engines from ships only when in place corrective actions can no longer be effected. Consequently, most LM2500 gas generators and power turbines have exhausted much of their useful life once they arrive at the depot for overhaul. Beginning in 1999, NAVSEA implemented a standardized workscope for these engines to ensure post repair life and performance goals were achieved. This paper discusses the contents of the standardize repair package and the resultant benefits and metrics associated with its execution at both military and commercial facilities.

An Overview of Selected Prognostic Technologies With Application to Engine Health Management

2006 ◽  
Author(s):  
Michael J. Roemer ◽  
Carl S. Byington ◽  
Gregory J. Kacprzynski ◽  
George Vachtsevanos
Keyword(s):  
Gas Turbine ◽  
Management System ◽  
High Performance ◽  
Health Management ◽  
Remaining Useful Life ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Prognostic Information ◽  
Generic Set ◽  
Engine Systems

The DoD has various vehicle platforms powered by high performance gas turbine engines that would benefit greatly from predictive health management technologies that can detect, isolate and assess remaining useful life of critical line replaceable units (LRUs) or subsystems. In order to meet these needs for next generation engines, dedicated prognostic algorithms must be developed that are capable of operating in an autonomous and real-time engine health management system software architecture that is distributed in nature. This envisioned prognostic and health management system should allow engine-level reasoners to have visibility and insight into the results of local diagnostic and prognostic technologies implemented down at the LRU and subsystem levels. To accomplish this effectively requires an integrated suite of prognostic technologies that can be applied to critical engine systems and can capture fault/failure mode propagation and interactions that occur in these systems, all the way up through the engine and eventually vehicle level. In the paper, the authors will present a generic set of selected prognostic algorithm approaches that can be applied to gas turbine engines, as well as provide an overview of the required reasoning architecture needed to integrate the prognostic information across the engine.

scholarly journals Strain Isolated Ceramic Coatings for Gas Turbine Engines

1985 ◽  
Author(s):  
R. P. Tolokan ◽  
J. B. Brady ◽  
G. P. Jarrabet
Keyword(s):  
Thermal Shock ◽  
Gas Turbine ◽  
Ceramic Coatings ◽  
Operating Conditions ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Shock Testing ◽  
Temperature Capability ◽  
Fiber Metal ◽  
Cooling Air

Plasma sprayed ceramic coatings are used in gas turbine engines to improve component temperature capability and cooling air efficiency. Strain isolated ceramic coatings offer improved coating life and increased insulating capability. A low modulus fiber metal strain isolator between ceramic and metal backing acts to reduce the stress on the ceramic during thermal cycling. Strain isolated coatings can tolerate greater ceramic thickness and broader operating conditions than nonstrain isolated coatings when subjected to thermal shock. Ceramic coatings are durable only within a narrow range of operating conditions. Coating designs should be based on real operating conditions for success. Thermal shock testing is useful for evaluating ceramic coatings if test and sample design are representative of the intended application.

Sign in / Sign up

Export Citation Format

Share Document