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2004-03-04
Future civil aircraft enginesAnders Lundbladh
Volvo Aero Engines, Anders Lundbladh2004-03-04, Slide 2
Framtidens Civila Jetmotorer
10110 Utg. 1
Boeing ”superefficient airplane” 7E7
“Raked wingtip” from 777-
300ER and 767-400ER
Long pods for engines with mixed
flow ?
BPR~10
Nozzle from
CF34-10
Tail wedge from MD-11
Two lobe body gives more design
freedom for passanger and freight space
Composite technology form the
Sonic Cruiser
Long slender wings
A
A
A-A
7/8 seats wide
A
A
Volvo Aero Engines, Anders Lundbladh2004-03-04, Slide 3
Framtidens Civila Jetmotorer
10110 Utg. 1
0
50
100
150
200
250
300
350
400
450
0 2000 4000 6000 8000 10000 12000 14000 16000 18000
Range km
Sea
ts 7677E7A330B777757A310A300A330 ny motor
Range and passanger
777-200LR not built yet7E7-domestic
close to 757 & A300/310
7E7s long range leaves a regions around present 767
A330 (also with new engines) shorter range than 7E7
7E7 gives ”777-range” for 200-pass. class
New engine
Volvo Aero Engines, Anders Lundbladh2004-03-04, Slide 4
Framtidens Civila Jetmotorer
10110 Utg. 1
Engine Technology
• Basically builds on TRENT900/GP7000/GE90
• Small improvements possible on compressor and turbine
• Higher BPR ca 10, OPR 45-50
• Slowly moving fans• Much emphasis on low
weight, aluminum• More Electric Aircraft
• SFC approx 14.5 mg/Ns at cruise M=0.85• Ca 8% better than CF6-80 on B767/A330• Ca 2% better than TRENT900/GP7000/GE90-115
VAC ICC
RR TRENT 900
Volvo Aero Engines, Anders Lundbladh2004-03-04, Slide 5
Framtidens Civila Jetmotorer
10110 Utg. 1
Fuel consumption
0,02
0,025
0,03
0,035
0,04
0 2000 4000 6000 8000 10000 12000 14000 16000
block distance km
fuel
l/pa
ss k
m
Boeing 7E7 baselineBoeing 7E7 stretchBoeing 777 300ERBoeing 767 300ERAirbus 330 200Boeing 7E7 domesticBoeing 757 300Airbus 300 600RAirbus 310 300
domestic as 757 & 15-20% better than A300/310
7E7-baseline comsumes approx. 10-15% less than 767-300ER 9% less than A330-200 7E7-stretch comsumes approx.
14% less than A330-200 and 9% less than777-300ER
Volvo Aero Engines, Anders Lundbladh2004-03-04, Slide 6
Framtidens Civila Jetmotorer
10110 Utg. 1
How efficient is an engine ?
SFC = vflight /( FHV tot )
tot = core transfer propulsive
thermal
nacelleengineflplfuel D
D
LgmmSFCm /)(
.
Volvo Aero Engines, Anders Lundbladh2004-03-04, Slide 7
Framtidens Civila Jetmotorer
10110 Utg. 1
Engine type and exhaust velocity
MTU Geared Fan
BPR 14 vut=340 m/s
Rolls-Royce Turbofan
BPR 7-8 vut = 400 m/s
GE UnDucted Fan
BPR 25 vut=280 m/s
Volvo Aero Engines, Anders Lundbladh2004-03-04, Slide 8
Framtidens Civila Jetmotorer
10110 Utg. 1
2004-03-03 GasTurb 9.0
4
6
8
10
12
14
16
18
20
Sp.
Fue
l Con
sum
ptio
n [g
/(kN
*s)]
0 .2 .4 .6 .8 1 1.2
Mach Number
Mach Number = 0 ... 1 Design Bypass Ratio = 14 ... 7
14
7
1%
T4_D iterated for cp_val7=5.6ZP13q2 iterated for V18q8id=0.8Specific fuel consumption
SFC
mg/Ns
Turbofan BPR 7
Geared Fan
BPR 14
Unducted Fan
BPR 25
Shock losses from fan blades
Typical Cruise Speed M=0.78-0.85
Volvo Aero Engines, Anders Lundbladh2004-03-04, Slide 9
Framtidens Civila Jetmotorer
10110 Utg. 1
Aircraft/Engine-parameters Affecting Certification Noise Data
Measuring points
Approach Takeoff
Sideline
Sideline: Depends mainly on the emitted sound energy from the jet.The dominant factor is the total installed thrust and to some extent the jet specific thrust (jet velocity - although the variation from engine to engine is quite small)
Takeoff: Depends mainly on the speed of climb which sets the distance to the measuring station [1/d^2] and the power of the noise source (see sideline).The rate of climb is set by the excess thrust/weight
Approach: Correlates mainly with drag and thrust needed during approach
Heathrow noise classification based on mean of sideline and takeoffNight landing restrictions from 2002: 95.9 EPNdBA
2-engine aircraft has more installed thrust than 4-engine aircraft
2500 m from runway start 6500m from brake release
450 m off centre line
Volvo Aero Engines, Anders Lundbladh2004-03-04, Slide 10
Framtidens Civila Jetmotorer
10110 Utg. 1
Driving Forces in Airline Engine DesignStakeholder Needs and ”Wants”
• Travelers• safety, cost of travel, speed, cabin noise and air quality
• Airlines• safety, cost, fuel consumption, maintenance (cost)
• Aircraft integrators• airframe compatibility, thrust, size & weight
• Airport neighbors• safety, exterior noise
• Authorities, public• safety, environmentally impacting emissions
Volvo Aero Engines, Anders Lundbladh2004-03-04, Slide 11
Framtidens Civila Jetmotorer
10110 Utg. 1
Fuel Efficiency Trends & Factors
• Since the fifties the fuel consumption of jetliners has been decreased by more than 50% …
• … stemming from more efficient aircraft …• Better aerodynamics• More efficient packing• New lighter materials and improved construction
• … & more efficient engines …• Better materials & cooled turbines allowing higher
temperatures.• Optimizing for higher temps higher pressures.• Arrival and optimization of the bypass turbofan.
• … but configuration changes have been few component technology has been pressed close to the limit.
Volvo Aero Engines, Anders Lundbladh2004-03-04, Slide 12
Framtidens Civila Jetmotorer
10110 Utg. 1
New Engine ConfigurationsAdvantages
• Geared fans• Potentially lower weight
• Unducted fans (propfans)• Higher propulsive efficiency
• Heat exchanged cycles• Higher thermal efficiency through:
• recovery of unused thermal exhaust energy• decrease of compression work
• Constant volume combustion• Higher thermal efficiency
Volvo Aero Engines, Anders Lundbladh2004-03-04, Slide 13
Framtidens Civila Jetmotorer
10110 Utg. 1
Engine Cycle Selection
• Aim for low operating cost• Preliminary studies may aim to minimize
• engine+fuel weight• take off weight
• Engine cycle must be translated into fuel burn, engine weight, installation weight and drag• Engine layout may be used to compute engine weight
Volvo Aero Engines, Anders Lundbladh2004-03-04, Slide 14
Framtidens Civila Jetmotorer
10110 Utg. 1
The Positive Carousel Effect
Lower drag
Lower thrust
Smaller engines
Less mission fuel
Smaller,lighter, aircraft
Higher engine efficiency Higher specific power