Development of Gas Turbine Performance Models using a

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LABORATORY OF THERMAL TURBOMACHINESNATIONAL TECHNICAL UNIVERSITY OF ATHENS http://www.ltt.mech.ntua.gr

ASME GT-2005-68678 Development of Gas Turbine Performance Models using a Generic Simulation Tool

Development of Gas Turbine Performance Models using a Generic Simulation Tool

Laboratory of Thermal TurbomachinesNational Technical University of Athens

A. Alexiou K. Mathioudakis

http://www.ltt.mech.ntua.gr

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Development of Gas Turbine Performance Models using a Development of Gas Turbine Performance Models using a Generic Simulation ToolGeneric Simulation Tool

§ Object-Oriented Gas Turbine Performance Modelling

§ Features of Simulation Tool

§Modelling Methods

§ Application Example

§ Engine Dynamics

§ Frequency Response

§ Adaptation to Test Data

§ Conclusions


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Object_OrientedObject_Oriented Gas Turbine Performance ModellingGas Turbine Performance ModellingObject-Oriented Programming (OOP) Features§ Encapsulation

§ Inheritance

§ Abstraction

§ Polymorphism

§ Aggregation

OOP Advantages§ Supports flexible and modular design

§ Facilitates code re-use

§Makes code evolution and maintenance easier

§ Provides user-friendly interface


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Object_OrientedObject_Oriented Gas Turbine Performance ModellingGas Turbine Performance ModellingGasTurbPredefined gas turbine configurations

Matlab-SimulinkNot fully OO

GSPOnly the developer can create new components

NPSS / OnyxRestricted availability

Use a commercially available general purpose OO simulation tool to model gas turbine components from which to build any engine configuration using a flexible and user-friendly interface


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§Modelling Methods


§ Engine Dynamics



§ Conclusions


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Features of Simulation ToolFeatures of Simulation Tool

Compressor

Duct

COMPONENT

PORT

§ Software COMPONENT = mathematical description of engine component

§ Components are joined together through their PORTS

§ PORTS define the set of variables transferred between connections

Component Code Component Icon


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Features of Simulation ToolFeatures of Simulation Tool

COMPONENTS are stored in a LIBRARY

Library files

Library elements

Library icons


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Features of Simulation ToolFeatures of Simulation ToolA PARTITION is created to define the mathematical model

Selecting Boundary

Conditions

Selecting Algebraic Variables


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Features of Simulation ToolFeatures of Simulation ToolDifferent EXPERIMENTS can be

made for a PARTITION

Initial Values for Dynamic & Algebraic Variables

Boundary Condition Values

Reporting

Steady State Calculation

Integration


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Main Window of Simulation ToolMain Window of Simulation Tool

Workspace Area

Output Area

Editing Area


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Graphical Component CreationGraphical Component Creation

Symbol Libraries Palette

Edit Area

Data Editor


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Graphical Output from SimulationGraphical Output from Simulation

Watch Variables

AreaPlotting

Area

Output Area


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§Modelling Methods


§ Engine Dynamics



§ Conclusions


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Modelling Methods: Component HierarchyModelling Methods: Component Hierarchy

GAS FUEL SHAFT FORCE

PORTS

COMPONENTS

ATMOSPHERE BLEED REINTRODUCTIONMIXER NOZZLEGasInGasOut

BURNER GasChannel

LPT_Exhaust

DUCT

INLET

GasTurbo

Compressor

Turbine

HPC

FAN

VOLUME DYNAMICS


PORTS


PORTS

COMPONENTS

ATMOSPHERE BLEED REINTRODUCTIONMIXER NOZZLEGasInGasOut

BURNER GasChannel

LPT_Exhaust

DUCT

INLET

GasTurbo

Compressor

Turbine

HPC

FAN

VOLUME DYNAMICS


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Shaft Dynamics

Gas Dynamics:• Conservation of Mass

• Conservation of Momentum

• Conservation of Energy

Heat Soakage• HP compressor (blades and casing)• Combustion (casing) • HP turbine (blades and casing)

Tm)(Tg*As*hdt

dTm*M*c

LK / * Re*C*0.0201 h

p

0.8

−=

=

2

602*

dtdXN*XN*JPW

π

=∆

( ) ( )[ ]

( ) ( ) ( )[ ]QPWH*WH*W*Volume

1pH*dtd

FA*pV*WA*pV*W*L1

dtdw

VolumeWW

dtd

outin

bodyoutin

outin

++−=−ρ

++−+=

−=

ρ

Modelling Methods: Dynamic ModellingModelling Methods: Dynamic Modelling


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§Modelling Methods


§ Engine Dynamics



§ Conclusions


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Specific Application Case: Turbofan ModelSpecific Application Case: Turbofan Model

HPCATMOSPHERE

BURNER

HPT

LPT

MIXER

Pt

INLET

FAN_TIP

FAN_ROOT

Pt

NOZZLE

F

DUCT_LP15 DUCT_BYPA

DUCT_LP26

BLEED_1 RET_1 RET_2

RET_3

BLEED_2

RET_4

LPT_Exhaust

FGN SFC EPR

VOLUMEDYNAMICS

2

1

12 13

263

41 42

49

6

8

2

1

12 13

263

41 42

49

6

8


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-0.50

-0.40

-0.30

-0.20

-0.10

0.00

0.10

0.20

P13 T13 W1 P26 T26 P3 T3 XNHP P41 T41 P6 T6 XNLP FGN

% D

IFFE

REN

CE

SLS

TOC

2

1

12 13

263

41 42

49

6

8

2

1

12 13

263

41 42

49

6

8

Model Comparison for SLS and TOC CasesModel Comparison for SLS and TOC Cases


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Corrected Flow

Pres

sure

Rat

io

OOMRTM

Model Comparison for Steady State Cases at SLSModel Comparison for Steady State Cases at SLS


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Corrected Flow

Pres

sure

Rat

io

OOMRTM

DECELACCEL

STEADY

0 2 4 6 8 10TIME (s)

WF

ACCELDECEL

Model Comparison for Transient CasesModel Comparison for Transient Cases


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§Modelling Methods


§ Engine Dynamics



§ Conclusions


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0

20

40

60

80

100

120

140

0 2 4 6 8 10TIME (s)

THR

UST

-6

-5

-4

-3

-2

-1

0

% D

iffer

ence% Difference

SD + VD + Heat Soakage

Shaft Dynamics

(SD)

SD + Volume Dynamics (VD)

0 2 4 6 8 10TIME (s)

WF

Engine Dynamics: Effect on ThrustEngine Dynamics: Effect on Thrust


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-10

-8

-6

-4

-2

0

2

4

6

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5TIME (s)

XM

AR

SD -

XM

AR

SD+V

D

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

FUEL VARIATION WITH TIME

WF

Gas Dynamics Effects on Compressor Surge Gas Dynamics Effects on Compressor Surge Margin during a Fuel SpikeMargin during a Fuel Spike


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§Modelling Methods


§ Engine Dynamics



§ Conclusions


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-3

-2.5

-2

-1.5

-1

-0.5

0

0.5

1

1 10 100

LOG [FREQUENCY (Hz)]

LOG

(GA

IN)

W1XNHPP3T6FGN

Gain = A0 / A0,f=0.01Hz

0

0.2

0.4

0.6

0.8

1

1.2

700 710 720 730 740 750 760 770 780 790 800Time (s)

WFE

(kg/

s)

WFE=0.7+0.4*sin(2pft)

Gain Variation with Frequency for Sinusoidal Fuel InputGain Variation with Frequency for Sinusoidal Fuel Input


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§Modelling Methods


§ Engine Dynamics



§ Conclusions


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Adaptive Performance Modeling: PrincipleAdaptive Performance Modeling: Principle

Actual Engine

Engine Model

Do data match?

Adjust model Parametersthrough MFs

Measured variables / Available Data

Predicted variables


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Adaptation to Test Data: Adaptation to Test Data: Implementation in OOPImplementation in OOP

Specifying Adaptation Factors

Specifying Measured Quantities


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Sample Results: Sample Results: Estimated Values of Adaptation Factors from Measurements Simulating a Deteriorated Engine

-2.5

-2

-1.5

-1

-0.5

0

0.5

1

SW12 SE12 SW2 SE2 SW26 SE26 SW41 SE41 SW49 SE49


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ConclusionsConclusions

§ An Object-Oriented simulation environment was used to create a re-usable library of gas turbine components

§ A model of a typical civil two-spool turbofan engine was developed by connecting the appropriate components from the library through an advanced graphical user interface

§ Both steady state and transient simulation results agreed well with those produced by an industry-accepted model

§ The ease of incorporating dynamic effects into the model and implementing adaptation factors (for matching a model to given measurements) was demonstrated

§ The approach presented allows for quick implementation of new models and rapid analysis of results


Documents

Development of Gas Turbine Performance Models using a