Gas Turbine of the Future

The Gas Turbine of the Future

Philip J. HaleyRolls-Royce Corporation

Indianapolis, Indiana

December 4, 2000

The gas turbine of the future

l Workshop: “Goals and Technologies for Future GasTurbine Engines”

l Technologies Are Only Important As They Service TheGoals

l The Goals Are Set By:n The Customersn The Regulatorsn The Competitors


l Our Commercial Customers Want:n Low Price (To Acquire, Operate, and Support)n Predictability of Engine Maintenancen Regulatory (Environmental) Compliancen Safety

l Our Military Customers Want:n Affordability (T/W, SFC, Flight Envelope, C.O.O. - 70%)

• C.O.O. = Development, Production, O & Sn Global Reach, Global Powern Reliability, Flexibility, Survivability


l Unanticipated Developments Which Could CauseTechnology Re-Directions:n Sudden Environmental Regulatory Changesn World Economics Changesn Public Reactions to Perceived Safety Issuesn Military Skirmishes, Wars


Business Drivers Impacting Technology Developmentl Historically, Governments Have Been the Leading Technology Sponsors

n Military Needs Pushed Envelopesn Shifting to Common Core, Joint (with Civil) Development Themes

l High Development/Certification Costsn Conflict With Stockholder Needsn Strategic Partnerships Help Address

l High Costs of Technical Competencen Industry Consolidationn Partnering With Universitiesn Outsourcing

l Customers’ (Civil and Military) Needs For Price/Affordability ExacerbateStress on Technology Funds


Some Key Technologies Likely to Change Furtherl Configuration, Designl Acousticsl Combustion/Emissionsl Controls & Diagnosticsl Coolingl Materials & Processing


Propfans provide high propulsive efficiency

90

80

70

60

500.5 0.6 0.7 0.8 0.9

Counter rotation

Prop fans

Single rotation

ModernTurbofan

Turboprop Prop

Flight mach number

Installedpropulsiveefficiency,

%


1000 oF Radial Magnetic Bearing

More electric engine

Complex mechanical powertrainreplaced by electrical power bus

Internal StarterGenerator

Magnetic Bearings


Aircraft noise issues

l Community noise levels in the vicinity of airports represent a growthbarrier for commercial aviation.

n More restrictive certification noise levels for aircraft will beimplemented in 2003

• 70 % of the current commercial fleet, including some of thenewest models, will be unable to comply with the most restrictiverule change under consideration

n Local airport regulations restrict access and levy heavier user feeson noisier aircraft

n Noise abatement operational procedures result in millions of dollarsof additional expense to the airlines yearly in terms of fuel and crewcosts


Aircraft noise issues (Continued)

l Lowering noise levels of the best current aircraft with today’s technology wouldlead to oversize, derated powerplants.

l Other technology areas have potential for negative impact upon noise.

n Reduced emissions combustion systems

n Highly loaded turbomachinery

l Dramatic reductions in engine noise will require fundamental changes to enginecycle and component architecture.

n Drastically reduced exhaust velocities to control jet mixing noise

n Fan designed for subsonic rotational speeds to eliminate noise related torotating shocks

Proprietary cross section deleted


Forward Swept Fan• Reduced “Buzzsaw” tones - shock retention• Reduced BPF tones - increased R-S spacing• Requires high strength, low density material

Reduced Airfoil Count Swept OGV• Reduced BPF tones• Reduced Fan broadband noise - reduced vane count

Optimized Forced Mixer• Reduced jet mixing noise

Alternate Cycles• UHBR, Geared Fans• Eliminate jet noise,minimize fan noise• Requires advanced materials, lightweight gear systems

Improved Acoustic Liner• Wider bandwidth• Optimum placement• Active/adaptive control


GAS TURBINE EMISSIONS ARE REGULATED TOINCREASINGLY STRINGENT LEVELS, IN BOTH AIRCRAFTAND INDUSTRIAL APPLICATIONS

25 ppm NOx 9/5 ppm NOx15/9 ppm NOxIndustrial

CAEP 4CAEP 2 Cruise and Climb Emissions LimitsAircraft

2000 2005 2010 2015 2020 2025

APPROACHES• Advanced Fuel Mixers

• Novel Configurations (i.e. Variable Geometry, Fuel Staging)• Advanced Cooling• Instability & Noise Control Methods

Advanced analytical combustor design systemSIGNIFICANTLY MORE ACCURATE MODELS (Turbulence/Chemistry, Spray, Atomization, etc)

PROBABILITY DENSITY FUNCTION METHOD

Conventional Models Fail for Premixed Combustors

Accurate Simulation of Production Combustors

3D FLOW ANALYSES WITH ROLLS-ROYCE PRECISE

COMPREHENSIVE FUEL INJECTION MODEL

All Key Liquid Fuel Spray Processes Modeled

MSA-cds2

Exit Temperature Traverse

1600

14001200

1000800

600

400

Te mp e rature (K)CONVENTIONAL (EBU) MODEL

16001400

1200

1000800

600400

Radial Swirler

LEAN PREMIXED LOW EMISSIONS COMBU STOR

Combus to r Te m pe rature (K)P DF MODEL RES ULTSPremixing Module

Main fuel

AirPilo t fue l

Filming

Air Ligam ents

S pray dis pers ion

Multicompone nt

atomizationS e condary

Fuel Evaporation

The gas turbine of the futurePremixed/prevaporized combustion system


Controls and diagnostics offer payoffs towards key customer - drivengoalsThemes:

• Simplicity Yields Reliability and Low Cost• Advanced Diagnostics Predict Maintenance Needs• Active Controls Improve Performance and Life

Likely Technical Developments:• Distributed Controls Using Low-Cost Electronics• Sensors for Fundamental Parameters and Health Monitoring• Non-Linear Engine Models to Minimize Sensors• Fuel Pump/Metering Simplicity, Robustness, and Safety• Diagnostics/Prognostics for Performance Trending• Intelligent Sensing of Operator Intent• Active Controls: Turbine Tip Clearance, Mag Bearings, Combustion Stability,

Compressor Stall, Vibration, Multivariable Integration

0

0.2

0.4

0.6

0.8

1

1960 1970 1980 1990 2000 2010 2020

Rel

ativ

e Te

mpe

ratu

re C

apab

ility

Cos

t ($)

Uncooled

Radial Cooling

Impingement Cooling

Film cooling

Advanced Film Cooling

Castcool

Single CrystalTranspirational Cooling

The gas turbine of the futureTurbine cooling technology has greatly enabled performance & reliability


Materials remain the single greatest barrier, and enabler, for gas turbine performance.

• Thrust/weight has increased 4X+ since 1950 - materials are single greatest contributor

• Reliability and cost are materials driven, and integrally interwoven with performance.

• The time lapse between major materials innovation and application is typically 15-25 years.

VSJ-1723

The gas turbine of the futureCoatings will continue to yield high payoffsagainst oxidation, corrosion, and erosion.


Year

1940 1960 1980 2000 2020

DemonstratorTechnology

ProductionTechnology

CoatedTurbineBlades

CooledTurbineBlades

UncooledTurbineBlades

Tem

pera

ture

cap

abili

ty

CMC(?)

SC NiAISC CastAlloysDS Cast

AlloysCast AlloysWrought Alloys

Turbine temperature progression reflects materials,cooling design, and aerodynamics


Metal matrix composites can yield significant weight payoffs.

AADC IHPTET compressor featuring Ti mmc blings


Ceramics offer potential step jumps in temperature and weight,but significant design challenges

Si3N4 turbine rotor after 1000-hour cyclic durability test


Phil’s Prognosisl Cyclel Suspension/Lubricationl Environmentall Controls & Diagnosticsl Materialsl Predictabilityl Minimized C.O.O.

Gas Turbine of the Future

Documents

n n n n low price

n n n affordability

envelopes n

crew costs n

engine noise

military customers

commercial customers

technology funds