Andrew Bradley FRAeS

An aero-engine vision of 2020Andrew Bradley FRAeSChief Design Engineer - Research & TechnologyRolls-Royce plc

November 2004

Reduce fuel consumption and CO2emissions by 50%

Targets are for new aircraft and whole industry relative to 2000The ACARE targets represent a doubling of the historical rate of improvement…

Reduce NOXemissions by 80%

Reduce perceived external noise by 50% (30db Cumulative)

* Advisory Council for Aerospace Research in Europe

Overall ACARE* environmental targets for 2020

Meeting the 50% fuel burn target needs changes in all areas

Contributions to CO2 Reduction

-50%

-40%

-30%

-20%

-10%

0%

Engines Airframe Air traffic management

and operations

Possible design solutions

Meeting the 30dB noise target needs changes in all areas

Contributions to noise reduction

-30dB

-20dB

-10dB

0dB

Aircraft & engine sources

Airframe perf.

Operations

Possible design solutions

Reduce fuel consumption and CO2emissions by 20%

Targets are for new engines and whole industry relative to 2000The ACARE targets represent a doubling of the historical rate of improvement…

Reduce NOXemissions by 80%

Reduce perceived external noise by 18 dB Cumulative

* Advisory Council for Aerospace Research in Europe

Engine ACARE* environmental targets for 2020

Turbofan Engine

Propulsive efficiencyThermal and

transfer efficiency

0.40

0.50

0.60

SFC

0.4

0.6

0.55

0.5

0.45

0.85

0.8

0.75

All parameters at35000 ft, 0.80 Mn

Affect on Future Product Capability

Propulsive Efficiency

Thermal * Transfer Efficiency

90’s

Recent engines

Current designs

Turbofan Engine

Pressure(atmospheres)

0

40Temperature (degrees C)

0

1500

Factors influencing thermal efficiency

10 20 30 40 50 60 70

65

60

55

50

45

40

Ther

mal

Effi

cien

cy

Overall Pressure Ratio

1400

1600

1800

2000

2200

TET (K)

Component efficiency 0.85

1960’s

1970’s1980’s

1990’s2020Target

Emissions constraints

At idle:Combustor pressure and temperature are low, and primary zone is weak (high AFR)

— inhibits chemical reaction which creates CO and UHCs

NOx & smoke reaction rate

10 20 30 40 50Air/fuel ratio (AFR)

+ve

-ve

Smoke

NOxDecreasing temperature

Primaryzone

Secondaryzone

At high power:Combustor temperature and pressure are high and primary zone is rich (low AFR) a fuel-rich mixture creates

smoke which is burned off in secondary zone

secondary combustion creates NOx establishing a trade with smoke

Forcing down emissions through innovation

Single-annular combustor70% CAEP 2

55% CAEP 2

Double-annular combustor

Main

Pilot

40% CAEP 2

Direct injection, lean burn single-annular combustor

EEFAE - ANTLE - proving technology for 2008

Trent 500 baseline engine with new technologies incorporated

Combustor• Lean burn

• Staged combustor



Controls• Distributed systems

• Fuel pump

Controls• Distributed systems

• Fuel pump

Health monitoring• Intelligent sensors

•Advanced EHM

Health monitoring• Intelligent sensors

•Advanced EHM

HP compressor• 5 stages

• Blisks

HP compressor• 5 stages

• Blisks

Whole engine• Increased temperatures

and pressures

Whole engine• Increased temperatures

and pressures

Oil system• Oil pump

• Air riding carbon seals• Brush seals

Oil system• Oil pump

• Air riding carbon seals• Brush seals

Accessory gearbox• Bearings

• Seals

Accessory gearbox• Bearings

• SealsIP turbine• Cooled

• Structural NGV• Variable capacity

IP turbine• Cooled

• Structural NGV• Variable capacity

LP turbine• 4 stages

• Novel construction

LP turbine• 4 stages

• Novel construction

HP turbine• Reduced blade numbers• Increased temperatures

•Contra-rotating

HP turbine• Reduced blade numbers• Increased temperatures

•Contra-rotating

ANTLE = Advanced Near-Term Low

Emissions

EU and UK government funded

EEFAE – CLEAN for 2012 - 2015

LPT•High speed

LPT•High speed





Recuperator• Heat exchanger

Recuperator• Heat exchanger

Compressor• Active-surge control

Compressor• Active-surge control

CLEAN = ComponentvaLidator for

Environmentally-Friendly Aero-eNgine

HP core and LPT with new technologies incorporated

Engine technology development

2004

FP5 FP62017

Engine validation

Development

201320092005

SILENCE(R)

Thermal efficiency

POA

VITAL

EEFAE(CLEAN / ANTLE)

Future programmes

Commercialisation

TRL 5 / TRL6

TRL6

TRL5

TRL5

TRL6

TRL8

Noise & Nacelle

HP Core low NOx

Architecture/Cycle

LP Core & Noise

Objective of VITAL

-10%

-5%

0%

5%

10%

15%

20%

25%

30%

4 5 6 7 8 9 10 11 12 13 14

EIS up to 80's

EIS 90's

BPR

∆ Weight/Thrust

EIS 80ÊÕs T

rend

EIS 90ÊÕs T

rend

BREAKTHROUGH

BR

EAK

THR

OU

GH

Weight breakdown of high BPR three shaft turbofan

Proportion of totalFan rotor & casing 18%

IP Comp. 5%Structures 15%

Shafts 3%LP Turb. 16%Nacelle 22%

Core & externals 21%100%

0%

10%

20%

30%

40%

7 9 11 13 15

Bypass ratio

% o

f dat

um e

ngin

e w

eigh

t

Fan systemIP comp.StructureShaftsLP turb.NacelleHP core & controls

Weight trends of subsystems

0%

100%

200%

300%

400%

7 9 11 13 15Bypass ratio

Fan tip radiusLP shaft torqueHPT bore radiusHPT rim radiusCore mass

Effect of BPR & shaft torque on core mass

50% torque increase of LP shaft at dia. avoids 200% mass increase

EU VITAL programme

DDTF engineDDTF engine

GTF engineGTF engine

CRTF engineCRTF engine

DDTF fan

High Speedbooster

Low Speedbooster

Low noise OGV

Variable Nozzle

Contrarotating

fan

CR Turbinestudy

Noise optimisedVHBR fans

Lightweightnovel materials

Lightweightcontainment

case

Specific to a VITALengine concept

Applicable to all 3 VITALengine concepts

Fan/IGVinteraction

Low NoiseTurbine

LightweightTurbine

High Torqueshaft

Lightweightstructures

Manufacturingtechniques

Also applicable to otherindustries

LightweightNacelle

Noise benefit from increased BPR

DDTF or GTFCRTF

REFERENCE LEVEL(pre 2000 engines)

VITAL OBJECTIVES

-20

-15

-10

-5

0

5

4 8 12 16BPR

DDTFCRTF

NOISE (Cumulative - EPNdB)

Currenttechnologies limit

DDTF or GTFCRTF


VITAL OBJECTIVES

-20

-15

-10

-5

0

5

4 8 12 16BPR

DDTFCRTF


DDTF or GTFCRTF


VITAL OBJECTIVES

-20

-15

-10

-5

0

5

4 8 12 16BPR

DDTFCRTF


Currenttechnologies limitCurrenttechnologies limit

University lead modelling work

Assessing impact of VITAL technologiesCombines

– Atmospheric modelling– Routes/ fleet mix– Aircraft performance– Engine performance

- Parametric– Engine weight

- Parametric– Engine emissions– Economic modelling

Optimiser software seeks ‘sweet spot’ for any scenario

Mission NOX modelling

Latest in evolution of Trent series of engines

Achieves improvements in line with ACARE goals

Trent 1000

-20%

-15%

-10%

-5%

0%

2000 2004 2008 2012 2016 2020Fuel

con

sum

ptio

n pe

r uni

t thr

ust a

t cru

ise

Trent 895

Trent 900

Trent 500

ACARE TARGET

Fuel consumption (and CO2) reduction

Trent 1000 prediction

0%

20%

40%

60%

80%

100%

2000 2004 2008 2012 2016 2020

NO

x em

issi

ons

rela

tive

to C

AEP2

Trent 895

Trent 1000 prediction

Trent 900

Trent 556

ACARE TARGET

NOx emissions reduction

-10

-8

-6

-4

-2

0

2000 2004 2008 2012 2016 2020Ave

rage

airc

raft

nois

e co

rrect

ed fo

r airc

raft

wei

ght (

dB)

Trent 800 powered aircraft

Predicted Trent 1000 powered aircraft

Trent 900 powered aircraftTrent 500 powered aircraft

ACARE TARGET

Aircraft noise reduction

Summary

There is significant potential for technology to further reduce the environmental impact of aviationACARE targets focus on noise, NOx and fuel burn (CO2 emissions) Good progress is being made towards these targets by combining the efforts of allSustained and increased levels of investment in technology will be required to achieve ACARE goals

But……although they are extremely challenging, are the ACARE goals sufficient for sustainable aviation?

An aero-engine vision of 2020Andrew Bradley FRAeSChief Design Engineer - Research & TechnologyRolls-Royce plc

November 2004

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Andrew Bradley FRAeS