Performance Model “Zooming” for In-Depth Component Fault Diagnosis

2010 ◽  
Vol 133 (3) ◽  
Author(s):  
N. Aretakis ◽  
I. Roumeliotis ◽  
K. Mathioudakis
Keyword(s):  
Fault Diagnosis ◽  
Measurement Data ◽  
Engine Performance ◽  
Main Tool ◽  
Performance Model ◽  
Diagnostic Methods ◽  
Engine Model ◽  
Path Component ◽  
1D Model ◽  
Compressor Performance

A method giving the possibility for a more detailed gas path component fault diagnosis by exploiting the “zooming” feature of current performance modeling techniques is presented. A diagnostic engine performance model is the main tool that points to the faulty engine component. A diagnostic component model is then used to identify the fault. The method is demonstrated on the case of compressor faults. A 1D model based on the “stage stacking” approach is used to “zoom” into the compressors, supporting a 0D engine model. A first level diagnosis determines the deviation of overall compressor performance parameters while zooming calculations allow a localization of the faulty stages of a multistage compressor. The possibility to derive more detailed information with no additional measurement data is established by the incorporation of empirical knowledge on the type of faults that are usually encountered in practice. Although the approach is based on known individual diagnostic methods, it is demonstrated that the integrated formulation provides not only higher effectiveness but also additional fault identification capabilities.

Performance Model “Zooming” for In-Depth Component Fault Diagnosis

2010 ◽  
Author(s):  
N. Aretakis ◽  
I. Roumeliotis ◽  
K. Mathioudakis
Keyword(s):  
Fault Diagnosis ◽  
Measurement Data ◽  
Engine Performance ◽  
Main Tool ◽  
Performance Model ◽  
Diagnostic Methods ◽  
Performance Modelling ◽  
Engine Model ◽  
Path Component ◽  
Modelling Techniques

A method giving the possibility for a more detailed gas path component fault diagnosis, by exploiting the “zooming” feature of current performance modelling techniques, is presented. A diagnostic engine performance model is the main tool that points to the faulty engine component. A diagnostic component model is then used to identify the fault. The method is demonstrated on the case of compressor faults. A 1-D model based on the “stage stacking” approach is used to “zoom” into the compressors, supporting a 0-D engine model. A first level diagnosis determines the deviation of overall compressor performance parameters, while “zooming” calculations allow a localization of the faulty stages of a multistage compressor. The possibility to derive more detailed information with no additional measurement data is established, by incorporation of empirical knowledge on the type of faults that are usually encountered in practice. Although the approach is based on known individual diagnostic methods, it is demonstrated that the integrated formulation provides not only higher effectiveness but also additional fault identification capabilities.

scholarly journals Axial Compressor Mean-Line Analysis: Choking Modelling and Fully-Coupled Integration in Engine Performance Simulations

2021 ◽  
Vol 6 (1) ◽  
pp. 4
Author(s):  
Ioannis Kolias ◽  
Alexios Alexiou ◽  
Nikolaos Aretakis ◽  
Konstantinos Mathioudakis
Keyword(s):  
Axial Compressor ◽  
Engine Performance ◽  
Engine Model ◽  
Multi Stage ◽  
Transient Simulations ◽  
Full Knowledge ◽  
Compressor Performance ◽  
First Time ◽  
Performance Calculation ◽  
Fully Coupled

A mean-line compressor performance calculation method is presented that covers the entire operating range, including the choked region of the map. It can be directly integrated into overall engine performance models, as it is developed in the same simulation environment. The code materializing the model can inherit the same interfaces, fluid models, and solvers, as the engine cycle model, allowing consistent, transparent, and robust simulations. In order to deal with convergence problems when the compressor operates close to or within the choked operation region, an approach to model choking conditions at blade row and overall compressor level is proposed. The choked portion of the compressor characteristics map is thus numerically established, allowing full knowledge and handling of inter-stage flow conditions. Such choking modelling capabilities are illustrated, for the first time in the open literature, for the case of multi-stage compressors. Integration capabilities of the 1D code within an overall engine model are demonstrated through steady state and transient simulations of a contemporary turbofan layout. Advantages offered by this approach are discussed, while comparison of using alternative approaches for representing compressor performance in overall engine models is discussed.

Adaptation Application to Engine Modelling

2007 ◽  
Author(s):  
Jude Iyinbor
Keyword(s):  
Measurement Data ◽  
Engine Performance ◽  
Performance Model ◽  
Operating Conditions ◽  
Adaptation Process ◽  
Design Point ◽  
Component Map ◽  
Important Measurement ◽  
Unknown Component ◽  
Selection Of

The optimisation of engine performance by predictive means can help save cost and reduce environmental pollution. This can be achieved by developing a performance model which depicts the operating conditions of a given engine. Such models can also be used for diagnostic and prognostic purposes. Creating such models requires a method that can cope with the lack of component parameters and some important measurement data. This kind of method is said to be adaptive since it predicts unknown component parameters that match available target measurement data. In this paper an industrial aeroderivative gas turbine has been modelled at design and off-design points using an adaptation approach. At design point, a sensitivity analysis has been used to evaluate the relationships between the available target performance parameters and the unknown component parameters. This ensured the proper selection of parameters for the adaptation process which led to a minimisation of the adaptation error and a comprehensive prediction of the unknown component and available target parameters. At off-design point, the adaptation process predicted component map scaling factors necessary to match available off-design point performance data.

Development and Integration of Rain Ingestion Effects in Engine Performance Simulations

2014 ◽  
Vol 137 (4) ◽  
Author(s):  
I. Roumeliotis ◽  
A. Alexiou ◽  
N. Aretakis ◽  
G. Sieros ◽  
K. Mathioudakis
Keyword(s):  
Engine Performance ◽  
Velocity Slip ◽  
Droplet Surface ◽  
Performance Model ◽  
Droplet Breakup ◽  
Test Case ◽  
Case Scenario ◽  
Worst Case ◽  
Engine Model ◽  
Component Models

Rain ingestion can significantly affect the performance and operability of gas turbine aero-engines. In order to study and understand rain ingestion phenomena at engine level, a performance model is required that integrates component models capable of simulating the physics of rain ingestion. The current work provides, for the first time in the open literature, information about the setup of a mixed-fidelity engine model suitable for rain ingestion simulation and corresponding overall engine performance results. Such a model can initially support an analysis of rain ingestion during the predesign phase of engine development. Once components and engine models are validated and calibrated versus experimental data, they can then be used to support certification tests, the extrapolation of ground test results to altitude conditions, the evaluation of control or engine hardware improvements and eventually the investigation of in-flight events. In the present paper, component models of various levels of fidelity are first described. These models account for the scoop effect at engine inlet, the fan effect and the effects of water presence in the operation and performance of the compressors and the combustor. Phenomena such as velocity slip between the liquid and gaseous phases, droplet breakup, droplet–surface interaction, droplet and film evaporation as well as compressor stages rematching due to evaporation are included in the calculations. Water ingestion influences the operation of the components and their matching, so in order to simulate rain ingestion at engine level, a suitable multifidelity engine model has been developed in the Proosis simulation platform. The engine model's architecture is discussed, and a generic high bypass turbofan is selected as a demonstration test case engine. The analysis of rain ingestion effects on engine performance and operability is performed for the worst case scenario, with respect to the water quantity entering the engine. The results indicate that rain ingestion has a strong negative effect on high-pressure compressor surge margin, fuel consumption, and combustor efficiency, while more than half of the water entering the core is expected to remain unevaporated and reach the combustor in the form of film.

Validation of a Mixed Flow Turbofan Performance Model in the Sub-Idle Operating Range

2003 ◽  
Author(s):  
Claus Riegler ◽  
Michael Bauer ◽  
Holger Schulte
Keyword(s):  
Steady State ◽  
Engine Performance ◽  
Performance Model ◽  
Maximum Power ◽  
Development Programs ◽  
Mixed Flow ◽  
Typical Application ◽  
Operating Range ◽  
Engine Model ◽  
Lighting Conditions

During turbofan development programs the evaluation of steady-state and transient engine performance is usually achieved by applying full thermodynamic engine models at least in the operating range between idle and maximum power conditions, but more recently also in the sub-idle operating range, e.g. for steady-state windmilling behavior and for starting, relight and shut down scenarios. The paper describes the setup, and in more detail the validation, of a full thermodynamic engine model for a two-spool mixed flow afterburner turbofan which is capable to run from maximum power down to zero speed and zero flow conditions in steady-state and transient mode. The validation is performed by using the model-based performance analysis procedure called ANSYN even in windmilling operation. Once the steady-state sub-idle model is validated the extension to transient sub-idle capability is achieved by simply adding the effects of rotor moment of inertia of the spools, while heat soakage effects are rather negligible without heat release in the burner. Especially lighting conditions in the burner are produced by such a validated sub-idle model inherently due to reliable data calculated at the burner entry station. The variety of applications of a validated full thermodynamic engine model is large. The performance data delivered is highly reliable and very consistent because the full operating range of the engine is covered with one model, and by appropriate means of speeding up the calculation even real-time capability may be achieved. In the paper synthesized data for an engine dry crank is compared to real engine test data as one typical application.

Sensitivity Analysis of an Aircraft Engine Model Under Consideration of Dependent Variables

2021 ◽  
Author(s):  
Julian Salomon ◽  
Jan Göing ◽  
Sebastian Lück ◽  
Matteo Broggi ◽  
Jens Friedrichs ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Engine Performance ◽  
Aircraft Engine ◽  
Interaction Effects ◽  
Performance Model ◽  
Engine Model ◽  
Overall Performance ◽  
Input Variables ◽  
The One ◽  
The Impact

Abstract In this work the impact of combined module variances on the overall performance of a high-bypass aircraft engine is investigated. Therefore, a comprehensive sensitivity analysis on the example of a turbofan engine performance model is provided by means of Kucherenko indices. Direct influences of selected model inputs on key model outputs as well as influences due to interaction effects between these input variables are identified. The selected input variables of the performance model are partly subject to considerable dependencies that are taken into account by the Kucherenko indices. The results confirm known direct influences of deterioration effects on the key performance parameters of the aircraft engine on the one hand, and provide profound insights into complex interaction effects between the components and their impact on the V2500-A1 aircraft engine performance on the other.

Effects of Anti-Icing System Operation on Gas Turbine Performance and Monitoring

2001 ◽  
Author(s):  
K. Mathioudakis ◽  
A. Tsalavoutas
Keyword(s):  
Gas Turbine ◽  
Engine Performance ◽  
Performance Model ◽  
False Alarms ◽  
System Operation ◽  
Diagnostic Ability ◽  
Engine Model ◽  
On Line ◽  
Industrial Gas Turbine ◽  
Engine Condition

The effect of operation of compressor bleed anti-icing on the performance of an industrial gas turbine is analysed. The effect of putting this system in operation is first qualitatively discussed, while the changes on various performance parameters are derived by using a computer engine performance model. The main point of the paper is the study of the effect of anti-icing system operation on parameters used for engine condition monitoring. It is shown that operation of the anti-icing system causes an apparent modification of such parameters, which may reduce the diagnostic ability of an on-line monitoring system and produce false alarms. It is shown that by incorporating the effect of anti-icing system operation into a diagnostic engine model, such problems can be avoided and the diagnostic ability of the system is not influenced by anti-icing activation. The analysis presented is substantiated through experimental data from a twin shaft gas turbine operating in the field.

Bayesian Network Approach for Gas Path Fault Diagnosis

2004 ◽  
Vol 128 (1) ◽  
pp. 64-72 ◽  
Author(s):  
C. Romessis ◽  
K. Mathioudakis
Keyword(s):  
Fault Diagnosis ◽  
Diagnostic Procedure ◽  
Deterministic Model ◽  
Probabilistic Approach ◽  
Engine Performance ◽  
Performance Model ◽  
Jet Engine ◽  
Turbine Performance ◽  
Gas Path Fault ◽  
Set Up

A method for solving the gas path analysis problem of jet engine diagnostics based on a probabilistic approach is presented. The method is materialized through the use of a Bayesian Belief Network (BBN). Building a BBN for gas turbine performance fault diagnosis requires information of a stochastic nature expressing the probability of whether a series of events occurred or not. This information can be extracted by a deterministic model and does not depend on hard to find flight data of different faulty operations of the engine. The diagnostic problem and the overall diagnostic procedure are first described. A detailed description of the way the diagnostic procedure is set-up, with focus on building the BBN from an engine performance model, follows. The case of a turbofan engine is used to evaluate the effectiveness of the method. Several simulated and benchmark fault case scenarios have been considered for this reason. The examined cases demonstrate that the proposed BBN-based diagnostic method composes a powerful tool. This work also shows that building a diagnostic tool, based on information provided by an engine performance model, is feasible and can be efficient as well.

Instructing the Principles of Gas Turbine Performance Monitoring and Diagnostics by Means of Interactive Computer Models

2000 ◽  
Author(s):  
K. Mathioudakis ◽  
A. Stamatis ◽  
A. Tsalavoutas ◽  
N. Aretakis
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Performance Monitoring ◽  
Measurement Data ◽  
Engine Performance ◽  
Performance Model ◽  
Operating Conditions ◽  
Engine Operation ◽  
Turbine Performance ◽  
Engine Components

The paper discusses how the principles employed for monitoring the performance of gas turbines in industrial duty can be explained by using suitable Gas Turbine performance models. A particular performance model that can be used for educational purposes is presented. The model allows the presentation of basic rules of gas turbine engine behavior and helps understanding different aspects of its operation. It is equipped with a graphics interface, so it can present engine operating point data in a number of different ways: operating line, operating points of the components, variation of particular quantities with operating conditions etc. Its novel feature, compared to existing simulation programs, is that it can be used for studying cases of faulty engine operation. Faults can be implanted into different engine components and their impact on engine performance studied. The notion of fault signatures on measured quantities is clearly demonstrated. On the other hand, the model has a diagnostic capability, allowing the introduction of measurement data from faulty engines and providing a diagnosis, namely a picture of how the performance of engine components has deviated from nominal condition, and how this information gives the possibility for fault identification.

scholarly journals Methods of Fault Diagnosis in Fiber Optic Current Transducer Based on Allan Variance

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Lihui Wang ◽  
Gang Chen ◽  
Jianfei Ji ◽  
Jian Sun ◽  
Jiabin Qian ◽  
...  
Keyword(s):  
Fault Diagnosis ◽  
Fiber Optic ◽  
High Reliability ◽  
Measurement Data ◽  
Allan Variance ◽  
Diagnostic Methods ◽  
Statistical Characteristics ◽  
Health State ◽  
Analysis Model ◽  
Calculation Results

To ensure low failure and high reliability of fiber optic current transducers (FOCTs), it is urgent to study methods of condition monitoring and fault diagnosis in FOCT. Faults in FOCT have statistical characteristics. With the analyzing of time domain and frequency domain features in fiber optic current transformers’ measurement data, we establish correspondence between the physical characteristics of key components in transformer and data features and then build diagnostic analysis model based on Allan variance. According to the Allan variance calculation results, we can diagnose fiber optic current transformer’s health state and realize faults location. Experiment results show that diagnostic methods based on Allan variance are accurate and effective to identify fault features.

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