A Gas Turbine Engine Model of Transient Operation Across the Flight Envelope

2011 ◽  
Author(s):  
Reza Rezvani ◽  
Metin Ozcan ◽  
Brian Kestner ◽  
Jimmy Tai ◽  
Dimitri N. Mavris ◽  
...  
Keyword(s):  
Neural Net ◽  
Transient Operation ◽  
Turbofan Engine ◽  
Turbine Engine ◽  
Engine Model ◽  
Complex Models ◽  
Model Execution ◽  
Transient Models ◽  
Fidelity Model ◽  
Good Agreement

This paper introduces a method to create engine transient models that retain the fidelity and non-linearity of complex models as well as simplicity and speed of lower fidelity linearized models. The method is based on the design of experiments (DOE) and neural network methodology to create an analytic non-linear model of engine transient operation which has the potential to be used in on-board and off-board applications. The feed forward neural net models were created for a high fidelity model of high bypass turbofan engine (truth model). The performance of the neural net models was verified against the truth model. The verification results showed good agreement between the output of the neural net models and the truth model. Initial investigations also showed a significant reduction in the model execution time.

An Analytical Approach to Gas Turbine Engine Model Linearization

2011 ◽  
Author(s):  
Gi-Yun Chung ◽  
Manuj Dhingra ◽  
J. V. R. Prasad ◽  
Richard Meisner ◽  
Steven Sirica
Keyword(s):  
Linearization Method ◽  
Perturbation Scheme ◽  
Proof Of Concept ◽  
Turbofan Engine ◽  
Turbine Engine ◽  
Reduced Order ◽  
Engine Model ◽  
Concept Validation ◽  
Model Linearization ◽  
Distance To The Boundary

This paper presents analytical linearization schemes of a reduced order aero-thermodynamic model of the generic back end of a turbofan engine. The proposed linearization scheme has advantages of flexibility and reusability over the commonly used linearization method based on the numerical perturbation scheme. Also, a blending algorithm employing the distance to the boundary as the weight has been incorporated into the linearization scheme to capture the change of the flow behaviour near bifurcating boundaries. The proposed linearization scheme is developed and applied to a back end model of a generic turbofan engine with bifurcations corresponding to choked/unchoked boundaries. This model is also used for proof of concept validation test.

Robust Kalman Filter Thrust Estimation in a Turbofan Engine

2006 ◽  
Author(s):  
Mattias Henriksson ◽  
Dan Ring
Keyword(s):  
Kalman Filter ◽  
Kalman Filters ◽  
Filter Design ◽  
The Other ◽  
Turbofan Engine ◽  
Turbine Engine ◽  
Engine Model ◽  
Lower Accuracy ◽  
Robust Kalman Filter ◽  
Linearization Point

This article will present that a robust Kalman filter design has a favorable property, when applied on thrust estimation on a low bypass turbofan gas turbine engine, compared to the regular Kalman filter design. This property is a larger operation range in parameters around the linearization point. On the other hand, the robust Kalman filter has marginally lower accuracy at the linearization point. This paper will present a method for describing the uncertainties in the engine model for use in the design of a robust Kalman filter. Both a regular Kalman filter and a robust Kalman filters are evaluated through simulations around a linearization point by using simulations of a nonlinear military turbofan engine.

An Efficient Transient Simulation Method for a Volume Dynamics Model

2018 ◽  
Author(s):  
Masahiro Kurosaki ◽  
Minoru Sasamoto ◽  
Kentaro Asaka ◽  
Keiko Nakamura ◽  
Daiki Kakiuchi
Keyword(s):  
Integration Method ◽  
Simulation Method ◽  
Euler Method ◽  
Test Model ◽  
Dynamics Model ◽  
Engine Operation ◽  
Turbine Engine ◽  
Engine Model ◽  
Influence Coefficients ◽  
Transient Simulations

This paper presents an efficient numerical integration method for a volume dynamics model in gas turbine engine transient simulations. It is a modified implicit Euler method that allows a time increment that would not be stable with the explicit Euler method. The Jacobian matrix of a nonlinear engine model is evaluated along the steady state engine operation line and scheduled as a function of the corrected shaft speed in advance, eliminating the necessity of computing during the simulation. The proposed method was applied to transient simulations of a compressor rig test model composed of a compressor, a nozzle with variable geometry and a volume placed between them. The eigenvalues of the simplified volume dynamics were analytically derived. It is shown that they are functions of the characteristic time of the volume defined by mass present in the volume divided by mass flow rate flowing into and out of the volume and dimensionless influence coefficients of nearby components.

Optimal Control of Turbine Engines

1979 ◽  
Vol 101 (2) ◽  
pp. 117-126 ◽  
Author(s):  
R. L. DeHoff ◽  
W. Earl Hall
Keyword(s):  
Optimal Control ◽  
Optimal Design ◽  
Control Design ◽  
Multivariable Control ◽  
Turbine Engines ◽  
Linear Modeling ◽  
Turbofan Engine ◽  
Turbine Engine ◽  
Design Procedures ◽  
Modeling Techniques

Multivariable control design for turbine engines has been studied for over 20 years. In the last 10 years, the application of linear, optimal design techniques has produced a number of turbine engine controllers. A group of these design procedures is described and a discussion of the procedures’ performance, complexity and implementation is presented. The design of a full-envelope controller for the F100 turbofan engine based on linear, optimal synthesis and locally linear modeling techniques is discussed. A perspective of optimal control design for turbine engines is presented and the future is examined.

scholarly journals Multi-Fidelity Simulation of a Turbofan Engine With Results Zoomed Into Mini-Maps for a Zero-D Cycle Simulation

2004 ◽  
Author(s):  
Mark G. Turner ◽  
John A. Reed ◽  
Robert Ryder ◽  
Joseph P. Veres
Keyword(s):  
Boundary Conditions ◽  
Fluid Dynamic ◽  
Thermodynamic Cycle ◽  
High Fidelity ◽  
Operating Characteristics ◽  
Cycle Model ◽  
Turbofan Engine ◽  
Engine Model ◽  
Cycle Simulation ◽  
Component Models

A Zero-D cycle simulation of the GE90-94B high bypass turbofan engine has been achieved utilizing mini-maps generated from a high-fidelity simulation. The simulation utilizes the Numerical Propulsion System Simulation (NPSS) thermodynamic cycle modeling system coupled to a high-fidelity full-engine model represented by a set of coupled 3D computational fluid dynamic (CFD) component models. Boundary conditions from the balanced, steady-state cycle model are used to define component boundary conditions in the full-engine model. Operating characteristics of the 3D component models are integrated into the cycle model via partial performance maps generated from the CFD flow solutions using one-dimensional meanline turbomachinery programs. This paper high-lights the generation of the highpressure compressor, booster, and fan partial performance maps, as well as turbine maps for the high pressure and low pressure turbine. These are actually “mini-maps” in the sense that they are developed only for a narrow operating range of the component. Results are compared between actual cycle data at a take-off condition and the comparable condition utilizing these mini-maps. The mini-maps are also presented with comparison to actual component data where possible.

New Model Based Gas Turbine Fault Diagnostics Using 1D Engine Model and Nonlinear Identification Algorithms

2009 ◽  
Author(s):  
Seyyed Hamid Reza Hosseini ◽  
Hiwa Khaledi ◽  
Mohsen Reza Soltani
Keyword(s):  
Gas Turbine ◽  
Diagnostic System ◽  
Gas Turbine Engine ◽  
Fault Model ◽  
Fault Identification ◽  
Identification System ◽  
Turbine Engine ◽  
Engine Model ◽  
Exhaust Temperature ◽  
Model Based

Gas turbine fault identification has been used worldwide in many aero and land engines. Model based techniques have improved isolation of faults in components and stages’ fault trend monitoring. In this paper a powerful nonlinear fault identification system is developed in order to predict the location and trend of faults in two major components: compressor and turbine. For this purpose Siemens V94.2 gas turbine engine is modeled one dimensionally. The compressor is simulated using stage stacking technique, while a stage by stage blade cooling model has been used in simulation of the turbine. New fault model has been used for turbine, in which a degradation distribution has been considered for turbine stages’ performance. In order to validate the identification system with a real case, a combined fault model (a combination of existing faults models) for compressor is used. Also the first stage of the turbine is degraded alone while keeping the other stages healthy. The target was to identify the faulty stages not faulty components. The imposed faults are one of the most common faults in a gas turbine engine and the problem is one of the most difficult cases. Results show that the fault diagnostic system could isolate faults between compressor and turbine. It also predicts the location of faulty stages of each component. The most interesting result is that the fault is predicted only in the first stage (faulty stage) of the turbine while other stages are identified as healthy. Also combined fault of compressor is well identified. However, the magnitude of degradation could not be well predicted but, using more detailed models as well as better data from gas turbine exhaust temperature, will enhance diagnostic results.

scholarly journals A Parametric Starting Study of an Axial-Centrifugal Gas Turbine Engine Using a One-Dimensional Dynamic Engine Model and Comparisons to Experimental Results: Part 1 — Model Development and Facility Description

1998 ◽  
Author(s):  
A. Karl Owen ◽  
Anne Daugherty ◽  
Doug Garrard ◽  
Howard C. Reynolds ◽  
Richard D. Wright
Keyword(s):  
Gas Turbine ◽  
Initial Conditions ◽  
Model Development ◽  
Ground Level ◽  
Gas Turbine Engine ◽  
Calibration Data ◽  
Gas Generator ◽  
Turbine Engine ◽  
One Dimensional ◽  
Engine Model

A generic one-dimensional gas turbine engine model, developed at the Arnold Engineering Development Center, has been configured to represent the gas generator of a General Electric axial-centrifugal gas turbine engine in the six kg/sec airflow class. The model was calibrated against experimental test results for a variety of initial conditions to insure that the model accurately represented the engine over the range of test conditions of interest. These conditions included both assisted (with a starter motor) and unassisted (altitude windmill) starts. The model was then exercised to study a variety of engine configuration modifications designed to improve its starting characteristics and thus quantify potential starting improvements for the next generation of gas turbine engines. This paper discusses the model development and describes the test facilities used to obtain the calibration data. The test matrix for the ground level testing is also presented. A companion paper presents the model calibration results and the results of the trade-off study.

Feasibility Study of a Radical Vane-Integrated Heat Exchanger for Turbofan Engine Applications

2020 ◽  
Author(s):  
Isak Jonsson ◽  
Carlos Xisto ◽  
Hamidreza Abedi ◽  
Tomas Grönstedt ◽  
Marcus Lejon
Keyword(s):  
Heat Exchanger ◽  
Gas Turbine ◽  
Conceptual Design ◽  
Feasibility Study ◽  
Compact Heat Exchanger ◽  
Turbofan Engine ◽  
Turbine Engine ◽  
Compression System ◽  
Last Stage ◽  
Pressure Compressor

Abstract In the present study, a compact heat exchanger for cryogenically fueled gas turbine engine applications is introduced. The proposed concept can be integrated into one or various vanes that comprise the compression system and uses the existing vane surface to reject core heat to the cryogenic fuel. The requirements for the heat exchanger are defined for a large geared-turbofan engine operating on liquid hydrogen. The resulting preliminary conceptual design is integrated into a modified interconnecting duct and connected to the last stage of a publicly available low-pressure compressor geometry. The feasibility of different designs is investigated numerically, providing a first insight on the parameters that govern the design of such a component.

scholarly journals Impact of Modeling Simplifications on Lightning Strike Simulation for Aeroengine

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Yi-fan Qian ◽  
Zhi-feng Ye ◽  
Hai-bo Zhang
Keyword(s):  
Simulation Analysis ◽  
Simulation Software ◽  
Simplified Model ◽  
Lightning Strike ◽  
Electromagnetic Simulation ◽  
Experimental Conditions ◽  
Turbofan Engine ◽  
Engine Model ◽  
Simulation Results ◽  
The Difference

With the development of electromagnetic simulation software and affordable hardware, it is allowed for us to complete simulations for EMC purposes. However, simulation demands will be immense when simulations for models with complex structures, especially aircraft components, have to be solved. Hence, it is meaningful to investigate how to minimize the computational demands. One of the solutions to reduce the simulation expense is the simplification for the simulated model. But the simplified model should be guaranteed to provide credible simulation results which do not deviate from the original model apparently. Generally, the difference between the simulation results and experimental data is estimated, or if the experimental conditions are not achieved, the comparison between the simplified model and the original one has to be analyzed, at least. This paper explores the electromagnetic simulation of a turbofan engine encountering lightning strike. With the simplifications of different components on the turbofan engine, the influences on induced currents of engine controller cables are simulated and analyzed based on the transmission-line matrix method. A combining method of components removal and geometric structure simplification is proposed to simplify the whole engine model. Simplified components include compressor, combustion chamber, turbine, and nozzle. The effects of different simplification methods are quantified, and the rationality of the simplified model is verified by simulation analysis.

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