scholarly journals Fault Signatures Obtained From Fault Implant Tests on an F404 Engine

1992 ◽  
Author(s):  
Richard W. Eustace ◽  
Bruce A. Woodyatt ◽  
Graeme L. Merrington ◽  
Tony A. Runacres
Keyword(s):  
Steady State ◽  
Diagnostic Techniques ◽  
Turbine Engines ◽  
Diagnostic Process ◽  
Gas Turbine Engines ◽  
Implant Tests ◽  
Increased Sensitivity ◽  
Transient Data ◽  
Fault Diagnostic ◽  
Fault Information

The fault diagnostic process for gas turbine engines can be improved if data acquired by an on-board engine monitoring system (EMS) are utilised effectively. In the commercial transport field, techniques are available to extract engine condition assessment information from steady-state EMS data. In a military environment, steady-state data are not always available, and therefore it is desirable to extract at least some of the information from transient data, such as during take-off. Fault signatures are presented for an F404 engine based on fault implant tests in a sea-level-static (SLS) test-cell. A comparison is then made between the fault coverage capabilities of fault diagnostic techniques based on the use of steady-state engine data with those using transient data. The important conclusions to emerge from this work are that for the range of faults examined, not only is there similar fault information contained within the transient data but the faults can be detected with increased sensitivity using these data.

Fault Signatures Obtained From Fault Implant Tests on an F404 Engine

1994 ◽  
Vol 116 (1) ◽  
pp. 178-183 ◽  
Author(s):  
R. W. Eustace ◽  
B. A. Woodyatt ◽  
G. L. Merrington ◽  
A. Runacres
Keyword(s):  
Steady State ◽  
Diagnostic Techniques ◽  
Turbine Engines ◽  
Diagnostic Process ◽  
Gas Turbine Engines ◽  
Implant Tests ◽  
Increased Sensitivity ◽  
Transient Data ◽  
Fault Diagnostic ◽  
Fault Information

The fault diagnostic process for gas turbine engines can be improved if data acquired by an on-board engine monitoring system (EMS) are utilized effectively. In the commercial transport field, techniques are available to extract engine condition assessment information from steady-state EMS data. In a military environment, steady-state data are not always available, and therefore it is desirable to exact at least some of the information from transient data, such as during take-off. Fault signatures are presented for an F404 engine based on fault implant tests in a sea-level-static (SLS) test cell. A comparison is then made between the fault coverage capabilities of fault diagnostic techniques based on the use of steady-state engine data with those using transient data. The important conclusions to emerge from this work are that for the range of faults examined, not only is there similar fault information contained within the transient data, but the faults can be detected with increased sensitivity using these data.

Rotordynamic Evaluation of an Advanced Multi-Squeeze Film Damper: Imbalance Response and Bladeloss Simulation

1991 ◽  
Author(s):  
J. F. Walton ◽  
H. Heshmat
Keyword(s):  
Steady State ◽  
Rotor System ◽  
Squeeze Film ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Flexible Rotor ◽  
High Eccentricity ◽  
Squeeze Film Damper ◽  
Wide Range ◽  
Damper Design

In this paper results of rotordynamic response and transient tests of a novel, high load squeeze film damper design, are presented. The spiral foil multi-squeeze film damper has been previously shown to provide two to four fold or larger increases in damping levels without resorting to significantly decreased damper clearances or increased lengths. By operating with a total clearance of approximately twice conventional designs, the non-linearities associated with high eccentricity operation are avoided. Rotordynamic tests with a dual squeeze film configuration were completed. As a part of the overall testing program, a flexible rotor system was subjected to high steady state imbalance levels and transient simulated bladeloss events for up to 0.254 mm (0.01 in) mass c.g offset or 180 gm-cm (2.5 oz-in) imbalance. The spiral foil multi-squeeze film damper demonstrated that the steady state imbalance and simulated bladeloss transient response of a flexible rotor operating above its first bending critical speed could be readily controlled. Rotor system imbalance sensitivity and logarithmic decrement are presented showing the characteristics of the system with the damper installed. The ability to accommodate high steady state and transient imbalance conditions make this damper well suited to a wide range of rotating machinery, including aircraft gas turbine engines.

A Generalized Fault Classification for Gas Turbine Diagnostics at Steady States and Transients

2007 ◽  
Vol 129 (4) ◽  
pp. 977-985 ◽  
Author(s):  
Igor Loboda ◽  
Sergiy Yepifanov ◽  
Yakov Feldshteyn
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Steady State ◽  
Gas Turbine ◽  
Diagnostic Techniques ◽  
Fault Classification ◽  
Diagnostic Process ◽  
Practical Realization ◽  
Transient Operation ◽  
Operational Conditions

Gas turbine diagnostic techniques are often based on the recognition methods using the deviations between actual and expected thermodynamic performances. The problem is that the deviations generally depend on current operational conditions. However, our studies show that such a dependency can be low. In this paper, we propose a generalized fault classification that is independent of the operational conditions. To prove this idea, the probabilities of true diagnosis were computed and compared for two cases: the proposed classification and the conventional one based on a fixed operating point. The probabilities were calculated through a stochastic modeling of the diagnostic process. In this process, a thermodynamic model generates deviations that are induced by the faults, and an artificial neural network recognizes these faults. The proposed classification principle has been implemented for both steady state and transient operation of the analyzed gas turbine. The results show that the adoption of the generalized classification hardly affects diagnosis trustworthiness and the classification can be proposed for practical realization.

Fault Diagnosis of Gas Turbine Engines From Transient Data

1989 ◽  
Vol 111 (2) ◽  
pp. 237-243 ◽  
Author(s):  
G. L. Merrington
Keyword(s):  
Fault Diagnosis ◽  
Gas Turbine ◽  
Sampling Rate ◽  
Diagnostic Information ◽  
Measurement Noise ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Input Output ◽  
Fault Parameters ◽  
Transient Data

The desirability of being able to extract relevant fault diagnostic information from transient gas turbine data records is discussed. A method is outlined for estimating the effects of unmeasured fault parameters from input/output measurements. The resultant sensitivity of the technique depends on the sampling rate and the measurement noise.

scholarly journals A Chambered Porous Damper for Rotor Vibration Control: Part II — Imbalance Response and Bladeloss Simulation

1991 ◽  
Author(s):  
J. Walton ◽  
M. Martin
Keyword(s):  
Steady State ◽  
Gas Turbine ◽  
Squeeze Film ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Turbine Engine ◽  
Wide Range ◽  
Squeeze Film Dampers ◽  
Damper Design ◽  
Control Part

In this paper, results of experimental rotordynamic evaluations of a novel, high load chambered porous damper design, are presented. The chambered porous damper concept was evaluated for gas turbine engine application since this concept avoids the non-linearities associated with high eccentricity operation of conventional squeeze film dampers. The rotordynamic testing was conducted under large steady state imbalance and simulated transient bladeloss conditions for up to 0.254 mm (0.01 in) mass c.g offset or 180 gm-cm (2.5 oz-in) imbalance. The chambered porous damper demonstrated that the steady state imbalance and simulated bladeloss transient response of a flexible rotor operating above its first bending critical speed could be readily controlled. Rotor system imbalance sensitivity and logarithmic decrement are presented showing the characteristics of the system with the damper installed. The ability to accommodate high steady state and transient imbalance conditions make this damper well suited to a wide range of rotating machinery, including aircraft gas turbine engines.

scholarly journals Transient Dynamics of Gas Turbine Engines

1993 ◽  
Author(s):  
A. R. Ganji ◽  
M. Khadem ◽  
S. M. H. Khandani
Keyword(s):  
Steady State ◽  
Differential Equations ◽  
Gas Turbine ◽  
Initial Conditions ◽  
Transient Behavior ◽  
Operating Point ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Linear Ordinary Differential Equations ◽  
General Methodology

Transient response of gas turbine engines depends on several parameters including engine type, components’ characteristics, and operational condition. This paper briefly describes the general methodology and approach for transient sensitivity analysis of various gas turbine engines, and the results of a computer program for analysis of the transient behavior of a single spool turbojet. Based on the method of intercomponent volumes, the general methodology applicable to transient analysis of any gas turbine based system has been developed. The method results in a set of stiff, time dependent non-linear ordinary differential equations (ODE) which can be solved by an appropriate ODE solver. The coefficients of the differential equations depend on the design and operational condition of the components represented by the component maps. The initial conditions of the ODE can be any steady state operating point of the engine. A steady state engine model provides these initial conditions. The program has the capability to match the components, and obtain a steady state operating point for the engine, accept a fuel protocol and predict the transient behavior of the engine. The program has produced satisfactory results for step, ramp and sinusoidal fuel inputs, as well as ramp variation in nozzle exit area.

A Generalized Fault Classification for Gas Turbine Diagnostics on Steady States and Transients

2006 ◽  
Author(s):  
Igor Loboda ◽  
Sergey Yepifanov ◽  
Yakov Feldshteyn
Keyword(s):  
Neural Networks ◽  
Artificial Neural Networks ◽  
Steady State ◽  
Gas Turbine ◽  
Correct Diagnosis ◽  
Diagnostic Techniques ◽  
Operating Conditions ◽  
Fault Classification ◽  
Diagnostic Process ◽  
Transient Operation

Gas turbine diagnostic techniques are often based on the recognition methods using the deviations between actual and expected thermodynamic performances. The problem is that the deviations depend on real operating conditions. However, our studies show that such a dependency can be reduced. In this paper, we propose the generalized fault classification that is independent of the operating conditions. To prove this idea, the averaged probabilities of the correct diagnosis are computed and compared for two cases: the proposed classification and the traditional one based on the fixed operating conditions. The probabilities are calculated through a stochastic modeling of the diagnostic process, in which a thermodynamic model generates deviations that are induced by the faults. Artificial neural networks recognize these faults. The proposed classification principle has been realized for both, steady state and transient operation of the gas turbine units. The results show that the acceptance of the generalized classification practically does not reduce the diagnosis trustworthiness.

Rotordynamic Evaluation of an Advanced Multisqueeze Film Damper—Imbalance Response and Blade-Loss Simulation

1993 ◽  
Vol 115 (2) ◽  
pp. 347-352 ◽  
Author(s):  
J. F. Walton ◽  
H. Heshmat
Keyword(s):  
Steady State ◽  
Rotor System ◽  
Squeeze Film ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Flexible Rotor ◽  
Squeeze Film Damper ◽  
Wide Range ◽  
Damper Design ◽  
Blade Loss

In this paper results of rotordynamic response and transient tests of a novel, high load squeeze film damper design are presented. The spiral foil multisqueeze film damper has been previously shown to provide two to fourfold or larger increases in damping levels without resorting to significantly decreased damper clearances or increased lengths. By operating with a total clearance of approximately twice conventional designs, the nonlinearities associated with high-eccentricity operation are avoided. Rotordynamic tests with a dual squeeze film configuration were completed. As a part of the overall testing program, a flexible rotor system was subjected to high steady-state imbalance levels and transient simulated blade-loss events for up to 0.254 mm (0.01 in.) mass c. g. offset or 180 g-cm (2.5 oz-in.) imbalance. The spiral foil multisqueeze film damper demonstrated that the steady-state imbalance and simulated blade-loss transient response of a flexible rotor operating above its first bending critical speed could be readily controlled. Rotor system imbalance sensitivity and logarithmic decrement are presented showing the characteristics of the system with the damper installed. The ability to accommodate high steady-state and transient imbalance conditions make this damper well suited to a wide range of rotating machinery, including aircraft gas turbine engines.

scholarly journals Simulation of Aircraft Gas Turbine Engines

1990 ◽  
Author(s):  
I. H. Ismail ◽  
F. S. Bhinder
Keyword(s):  
Steady State ◽  
Computer Program ◽  
Gas Turbine ◽  
Performance Characteristics ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Steady State Operation

The paper describes a computer program to simulate aircraft gas turbine engines. The program has been written for IBM compatible micro computers and is modular in its approach. Either analytical equations or detailed performance characteristics of individual components are used to model the steady state operation of the complete engine.

Simulation of Aircraft Gas Turbine Engines

1991 ◽  
Vol 113 (1) ◽  
pp. 95-99 ◽  
Author(s):  
I. H. Ismail ◽  
F. S. Bhinder
Keyword(s):  
Steady State ◽  
Computer Program ◽  
Gas Turbine ◽  
Performance Characteristics ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Steady State Operation

The paper describes a computer program to simulate aircraft gas turbine engines. The program has been written for IBM-compatible microcomputers and is modular in its appraoch. Either analytical equations or detailed performance characteristics of individual components are used to model the steady-state operation of the complete engine.

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