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Keep it simple, dummy
New York City, April 3, 2007
CFMI Proprietary
Basic Jet Propulsion
THRUST = mV
Massflowm
Speed V
CFMI Proprietary
Different Types of Aircraft Propulsion
PROPELLER PROPULSION
HYBRID PROPULSION
JET PROPULSION
CFMI Proprietary
First Look at a Jet Engine
A big pipe
The fan
CFMI Proprietary
The Fan
The fan sucks airfrom the outside
The fan
Air
CFMI Proprietary
The Jet Engine Principle
The fuel brings the energy to the system
Compressor Combustor
Fuel
Turbine
The turbine drives the compressor
Air
CFMI Proprietary
THE CYCLE
Part of E3 used to drive the compressor
Why Does it Work? Compressor
1
Turbine
3
Entropy
Energy
E3
Energy E1 << Energy E3
Rest of E3 used to generate thrust
Combustor
2
Fuel
E1
Constant pressure linemax pressure in engine
2 3
Constant pressure lineambient pressure
1« 0 »
OUTSIDE AIR « 0 »
m
V
CFMI Proprietary
Jet Engine Differences
Turbojet engine1 shaftSmall diameter
Modern commercialjet engine2 or 3 shaftsLarge diameter
CFMI Proprietary
The Concept of By-pass Ratio
3
3
2
2
By-pass ratio =Mass flow / mass flow3 2
Increase in by-pass ratio improves SpecificFuel Consumption (SFC)TRUST ME!
1Air
CFMI Proprietary
Jet Engine Differences
Thrust = mV
Flow m
VLow by-passratio engine
Flow mV
High by-passratio engine
Low mass flow mHigh speed V
High mass flow mLow average speed V
CFMI Proprietary
1
1
2
2
3
3
Front view
Aft looking forwardBy pass ratio schematic
LOW FLOW
HIGH SPEED
HIGH FLOW, LOW SPEED
2 GENERATES 20% OF THE THRUST
3 GENERATES 80% OF THE THRUST
CFMI Proprietary
All About By-pass RatioLow by-passratio engine
High by-passratio engine
By-pass ratios have increased over timeCurrent engines: By-pass ratios 5 to 6
Low by-pass ratio engine
High by-pass ratio engine
-20%
SFCSFC: Fuel burntby engine ona test stand
New/future engines: By-pass ratio 10
Characterizes quality of the
engine
CFMI Proprietary
Noise Signature
High by-passratio engine
High by-passratio engine
Low by-passratio engineLow by-passratio engine
High by-pass ratio improves noise signature
CFMI Proprietary
GROUND CLEARANCE
By-pass Ratio Limitations
By-pass ratio can be limited by installation on A/C
CFMI Proprietary
By-pass Ratio Limitations
By-pass ratio can be limited by fuel burn
Fuel burn (FB) is the fuelburnt over
a given mission
Fuel burn depends on:- SFC (engine quality): - Drag :
Drag
Weight
- Weight :
FBFBFB
CFMI Proprietary
Going Beyond the CompromiseFuel Burn
Improvement
NoiseImprovement
Technologyjump
INCREASE IN BYPASS RATIO
A380 ENGINES
OPTIMIZED FOR NOISE RATHER THAN FUEL
BURN
CFMI Proprietary
The Maximum Cycle Temperature
Maximum temperature
CFMI Proprietary
The Plus of Increasing Max Cycle Temperature
1960 1970 1980 1990 2000 2010 YEAR
Max
imum
cyc
le te
mpe
ratu
re
Maximum metal temperature
Increasing max cycle temperaturesimproves Specific Fuel ConsumptionTRUST ME!
CFMI Proprietary
The Minuses of Increasing Max Cycle Temperature
HOT• Hotter engine burns more parts
Higher maintenance costs
• Nitrogen oxides (NOx) are produced at high temperature
NOx vs CO2 =A real challenge
NOx
SFC/CO2
High pressureturbine
NOxSFC/CO2
Max cycle temperature
ALTERNATIVE IS MORE SOPHISTICATED MATERIAL BUT MORE EXPENSIVE
CFMI Proprietary
The Green House Effect: Climate Change
CFMI Proprietary
Air Quality
OZONE + NOx + PARTICLES +CO + UHC
INDEX 3
INDEX 7
?VERY SMALL
LEVELS
CFMI Proprietary
Engine Main Operational Cost Drivers
4001T-07/01
Take-off+
climb
Cruise
Descent1 Take-off = 1 cycle1 Take-off = 1 cycle
• Maintenance cost
Typical Simplified mission
• Life Limited Parts (LLP) cost
• Fuel Burn
Mainly related to number of cycles(engine deterioration mostly occurs at T/O)
Only related to number of cycles
Cruise length is main driver
ENGINE COST OF OPERATION :
A MIX OF MAINTENANCE COST, LLP & FUEL COSTS
CFMI Proprietary
Maintenance / LLP costs are 30% of the cost
Long Range vs Short/Medium Range Missions
4002T-09/99
Long range A/C
Fuel Burn is main driver
Short/medium range A/C
Cruise
1 cycle1 cycle
1cycle
1cycle
1cycle
1cycle
1cycle
1cycle
1cycle
1cycle
1cycle
1cycle
1cycle
1cycle
6 to 12 hours
1 to 2 hours / cycle
• Low number of cycles
• High number of cycles
• Cruise is main part of the mission
• Short cruise
T/O+
climb
Cruise
Descent
T/O+
climb
Descent
FOR SHORT / MEDIUM RANGE AIRCRAFT,
CYCLE RELATED COSTS ARE VERY STRONG DRIVERS
CFMI Proprietary
Maintenance Cost and Design
4455T-04/02
HOT SECTION MATERIAL COST :
60%OF TOTAL
MATERIAL COST
* Excl. Fees, tests and LLPs
SHOP VISIT COST (SVC)*
HOT SECTION MATERIAL COST = 36% of SVCMATERIAL COST (rest of the engine) = 24% of SVCLABOUR = 30% of SVCREPAIRS = 10% of SVC
AND
TOTAL MATERIAL COST : 60%
OF SHOP VISIT COST*
HOT SECTION COST IS MAIN DRIVER
FOR SHOP VISIT COST
CFMI Proprietary
Engine Architecture
Burns more fuel2 to 3%
Burns more parts20% more
expensive shop visit
Single Stage HP Turbine
Two-Stage HP Turbine
Both can do the job but are not equivalentOn paper, both should have similar time on wing
More hot section parts
CFMI Proprietary
The effect of fuel priceSingle aisle, high cycle A/C
1 stage HPT better 2 stage HPT better
Today
Fuel cost2 stage HPT
vs 1 stage HPT
MaintenanceCost 2 stage HPTvs 1 stage HPT
Cost2 stage HPT
vs 1 stage HPT
Cost
Fuel cost$/gallon
3
CFMI Proprietary
One Architecture, One Application
CFM56 PW6000V2500
BR715
New V2500
CF6 PW4000
CF34-3 CF34-8CF34-10
GE90
JT9D Trent 700* Trent 800* Trent 900/1000*
Narrow BodyNarrow Body(Short & medium range)
Regional jetRegional jet(Short range)
Wide BodyWide Body(Long range)
SaM146
Two stage HP Turbine
GP7000
1965 1975 1985 1995 2005
Certification Date
future Design change
PW2000Design change
Single stage HP Turbine
Design change???
New CFM
GEnX
HIG
H C
YCLE
LOW
CYC
LE
CFMI Proprietary
Becoming Global Over Time
The 90’sCOST OF
OWNERSHIPThe 80’s
SFC
The 70’sTHRUST
The 2000’sSUSTAINABLE DEVELOPMENT
EnvironmentalIssues
Superimposed
CFMI Proprietary
SFCsystem
Emissions
Maintenance cost
The 2000’sIntegration Cycle
Acquisition cost
Noise
Architecture
Optimize System with Constraints• Regulations/Taxes/Charges• Minimize Cost of Ownership
Sust Dev industrial process
Environmental Issues Now Part Of The Equation
CFMI Proprietary
Make It Simple, Dummy
HotCold
Cold
Big
Big
Small
>
>
2 Big
2 Cold
1 Small
1 Hot
LOW CO2LOW FUEL
BURN
LIGHT
LOW FUELCONSUMPTION
LOW NOx
COLD
HOT
BIGCOLD
LOWMAINTENANCE
COST
SMALL
BIG
LOW NOISE
CFMI Proprietary
CFMI Proprietary
CFMI Proprietary
We Have A Secret Dream……
Remember: Big engine, innovative installation
We may not be there yet !!!
CFMI Proprietary