Future civil aircraft engines Anders Lundbladh

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



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



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



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



10110 Utg. 1

How efficient is an engine ?

SFC = vflight /( FHV tot )

tot = core transfer propulsive

thermal

nacelleengineflplfuel D

D

LgmmSFCm /)(

.



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



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



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



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



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.



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



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



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

Documents

Future civil aircraft engines Anders Lundbladh