Adaptive modeling of aircraft engine performance degradation model based on the equilibrium manifold and expansion form

2013 ◽  
Vol 228 (8) ◽  
pp. 1246-1272 ◽  
Author(s):  
Xiaofeng Liu ◽  
Ye Yuan ◽  
Jing Shi ◽  
Lei Zhao
Keyword(s):  
Engine Performance ◽  
Aircraft Engine ◽  
Performance Degradation ◽  
Adaptive Modeling ◽  
Degradation Model ◽  
Model Based ◽  
Equilibrium Manifold ◽  
Expansion Form

Environmental Influences on Engine Performance Degradation

2010 ◽  
Author(s):  
Tobias Wensky ◽  
Lutz Winkler ◽  
Jens Friedrichs
Keyword(s):  
Environmental Effects ◽  
Environmental Influences ◽  
Engine Performance ◽  
Aircraft Engine ◽  
Performance Degradation ◽  
Gas Temperature ◽  
Engine Model ◽  
Regional Effects ◽  
Time Calculation ◽  
Exhaust Gas Temperature

Environmental influences have an increasing effect on the performance degradation and durability of modern aircraft engines. The study provides information on environmental effects using in-flight engine data and results of engine overhauls performed at MTU Maintenance. According to these investigations global regions are classified into erosive and anthropogenic polluted areas. Both types of regional effects significantly degrade performance and engine durability. The investigation, which is based upon the in-flight data taken from Engine Trend Monitoring (ETM), provides one approach for the estimatation of environmental effects on aircraft engine performance degradation. The results of the monitored engines provide detailed information on the environmental effects atlocal airports. The Exhaust Gas Temperature (EGT) that has been measured under flight conditions is compared with a calculated EGT of a calibrated fully thermodynamic gas path engine model (MOPS). Therefore, the EGT also serves as an indicator for performance degradation, increase of specific fuel consumption and the need for on-wing maintenance actions. Further information provided by the engine shop visit data at MTU Maintenance allows for an estimation of environmental influences on durability and overhaul costs. The on-wing time of maintained shop visit data is compared with a model for on-wing time calculation, whereas variations in durability were observed and analyzed under the aspects of environmental influences. Depending on the variations, corrections were made by defining the factors contributing to the classifications of environmental effects. These corrective factors provide information on reduced durability and increased operating costs. The result of the ETM performance degradation analysis shows significant variations in engine performance degradation as a result of specific regional operation. The analyses of maintenance data as well as performance degradation measured by ETM show remarkable environmental effects on engine durability and an increase in maintenance costs.

Nonlinear System Modeling based on System Equilibrium Manifold

2018 ◽  
Vol 35 (4) ◽  
pp. 395-402 ◽  
Author(s):  
X. F. Liu ◽  
D. X. Zhang ◽  
N. Y. Xue
Keyword(s):  
Nonlinear System ◽  
System Modeling ◽  
Equilibrium Points ◽  
Nonlinear Behavior ◽  
Aircraft Engine ◽  
Good Precision ◽  
Nonlinear System Modeling ◽  
Equilibrium Manifold ◽  
System Equilibrium ◽  
Expansion Form

Abstract The main objective of the present paper is to provide an approximate method for nonlinear system with a family of equilibrium points (EPs). By investigating the system’s equilibrium manifold (EM) and its expansion form, a class of nonlinear system is modeled analytically. The property of the EM expansion form and the effect of mapping design and parameterizing method to the model have been discussed. Then an approximate nonlinear model for aircraft engine was applied, followed by an identification procedure for aircraft engine. It is shown that the modeling method based on system’s EM can not only comply with the system physical characteristics, but also satisfy the accuracy of modeling requirement. Numerical simulations are given to demonstrate the good precision in capturing the nonlinear behavior of nonlinearities and a simpler structure.

scholarly journals Optimal Tuner Selection for Kalman Filter-Based Aircraft Engine Performance Estimation

2009 ◽  
Vol 132 (3) ◽  
Author(s):  
Donald L. Simon ◽  
Sanjay Garg
Keyword(s):  
Kalman Filter ◽  
Estimation Error ◽  
Engine Performance ◽  
Aircraft Engine ◽  
Operating Conditions ◽  
Performance Estimation ◽  
Experimental Simulation ◽  
Tuning Parameter ◽  
Estimation Accuracy ◽  
On Line

A linear point design methodology for minimizing the error in on-line Kalman filter-based aircraft engine performance estimation applications is presented. This technique specifically addresses the underdetermined estimation problem, where there are more unknown parameters than available sensor measurements. A systematic approach is applied to produce a model tuning parameter vector of appropriate dimension to enable estimation by a Kalman filter, while minimizing the estimation error in the parameters of interest. Tuning parameter selection is performed using a multivariable iterative search routine that seeks to minimize the theoretical mean-squared estimation error. This paper derives theoretical Kalman filter estimation error bias and variance values at steady-state operating conditions, and presents the tuner selection routine applied to minimize these values. Results from the application of the technique to an aircraft engine simulation are presented and compared with the conventional approach of tuner selection. Experimental simulation results are found to be in agreement with theoretical predictions. The new methodology is shown to yield a significant improvement in on-line engine performance estimation accuracy.

A Flight Simulation Vision for Aeropropulsion Altitude Ground Test Facilities

2005 ◽  
Vol 127 (1) ◽  
pp. 8-17 ◽  
Author(s):  
Milt Davis ◽  
Peter Montgomery
Keyword(s):  
System Performance ◽  
Engine Performance ◽  
Aircraft Engine ◽  
Flight Simulation ◽  
Propulsion System ◽  
Test Facility ◽  
Flight Testing ◽  
Test Environment ◽  
Ground Test ◽  
Aircraft System

Testing of a gas turbine engine for aircraft propulsion applications may be conducted in the actual aircraft or in a ground-test environment. Ground test facilities simulate flight conditions by providing airflow at pressures and temperatures experienced during flight. Flight-testing of the full aircraft system provides the best means of obtaining the exact environment that the propulsion system must operate in but must deal with limitations in the amount and type of instrumentation that can be put on-board the aircraft. Due to this limitation, engine performance may not be fully characterized. On the other hand, ground-test simulation provides the ability to enhance the instrumentation set such that engine performance can be fully quantified. However, the current ground-test methodology only simulates the flight environment thus placing limitations on obtaining system performance in the real environment. Generally, a combination of ground and flight tests is necessary to quantify the propulsion system performance over the entire envelop of aircraft operation. To alleviate some of the dependence on flight-testing to obtain engine performance during maneuvers or transients that are not currently done during ground testing, a planned enhancement to ground-test facilities was investigated and reported in this paper that will allow certain categories of flight maneuvers to be conducted. Ground-test facility performance is simulated via a numerical model that duplicates the current facility capabilities and with proper modifications represents planned improvements that allow certain aircraft maneuvers. The vision presented in this paper includes using an aircraft simulator that uses pilot inputs to maneuver the aircraft engine. The aircraft simulator then drives the facility to provide the correct engine environmental conditions represented by the flight maneuver.

scholarly journals An Integrated Approach for Aircraft Engine Performance Estimation and Fault Diagnostics

2013 ◽  
Vol 135 (7) ◽  
Author(s):  
Donald L. Simon ◽  
Jeffrey B. Armstrong
Keyword(s):  
Kalman Filter ◽  
Engine Performance ◽  
Aircraft Engine ◽  
Fault Isolation ◽  
Performance Estimation ◽  
Estimation Accuracy ◽  
Fault Diagnostics ◽  
Tuning Parameters ◽  
Performance Deterioration ◽  
Health Parameters

A Kalman filter-based approach for integrated on-line aircraft engine performance estimation and gas path fault diagnostics is presented. This technique is specifically designed for underdetermined estimation problems where there are more unknown system parameters representing deterioration and faults than available sensor measurements. A previously developed methodology is applied to optimally design a Kalman filter to estimate a vector of tuning parameters, appropriately sized to enable estimation. The estimated tuning parameters can then be transformed into a larger vector of health parameters representing system performance deterioration and fault effects. The results of this study show that basing fault isolation decisions solely on the estimated health parameter vector does not provide ideal results. Furthermore, expanding the number of the health parameters to address additional gas path faults causes a decrease in the estimation accuracy of those health parameters representative of turbomachinery performance deterioration. However, improved fault isolation performance is demonstrated through direct analysis of the estimated tuning parameters produced by the Kalman filter. This was found to provide equivalent or superior accuracy compared to the conventional fault isolation approach based on the analysis of sensed engine outputs, while simplifying online implementation requirements. Results from the application of these techniques to an aircraft engine simulation are presented and discussed.

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