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How the More Electric Aircraft is influencing
a More Electric Engine and More!
Electrical Technologies for Aviation of the Future
Tokyo, 26-27 March, 2015
David Koyama
Director of Engineering & Technology– Rolls-Royce Japan
2
The Present –
Key driving factor
Why the More Electric Aircraft has changed the gas turbine
The Future –
Key Driver
How the all Electric Aircraft will impact the propulsion system
The move to a More Electric Engine Contents
3
Aerospace Industry Challenges
Overall ACARE* Environmental Targets for 2020
The ACARE targets represent a doubling of the historical rate of improvement…
* Advisory Council for Aerospace Research in Europe
Targets are for new aircraft and whole industry relative to 2000
Reduce fuel consumption and CO2 emissions by 50%
Reduce NOX emissions by 80%
Reduce perceived external noise by 50%
The move to a More Electric Engine Present - Key driver
4
Increase propulsion system efficiency
RNP FMS/engine integration
Increase thermal efficiency
Increase transmission efficiency
Nacelle
Power management
Increase propulsion efficiency
Optimized climb
Reduce thrust
requirement
Increase L/D
Reduce weight
Reduce holding
Improve routing to avoid headwinds
Fly fewer miles
Operator / Air Traffic Management
Routes to fuel burn reduction
Airframer
Propulsion system supplier
5 How the More Electric Aircraft has changed the Gas Turbine
IN: Fuel Start air OUT: Thrust HP air Wing anti-ice air Electricity Hydraulics
Fuel
Start air
Electricity (hotel mode)
Cabin air (hotel mode)
Air
Hydraulics
Cabin air
Pneumatic
Wing anti-
ice
ECS
RAT
APU
Cabin air HP air
Electricity,
Hydraulics
(emergency)
Conventional More electric
IN: Fuel Electric start OUT: Thrust Electricity
Fuel
Electric start
Electricity (hotel
mode only)
Cabin air
Air
Options Electrical actuation
Cabin air
Electrical
wing anti-
icing
New
APU
design
Bleed
Deleted
RAT
ECS
Increased complexity of system control including Engine
6 How the More Electric Aircraft has changed the
Gas Turbine
1980 2000 1990 2020 2030 2010
Po
we
r R
eq
uir
em
en
ts [
kW]
500
1000
1500
2000
Hybrid / All Electric Aircraft
More Electric Aircraft
B787
A380
F4 - 60kW
F35
F14
Conventional
B767
Progression of Aircraft Electrical Power Requirements
7
Power Optimised Aircraft Project
• 43 European aerospace partners
The objectives were:
• To test candidate technologies
• To find out what are the critical design issues associated with installing these technologies.
• The engine test was to prove the capability of these technologies it was not a product
demonstrator
Examples of Previous Rolls-Royce Experience
SEED (Small Electric Engine Demonstrator)
• Single Spool Core Demonstrator Engine
on Build Stand
• The first in-house Rolls-Royce engine
with embedded electric start
8
The Trent 1000 has been tailored for the Boeing 787 Dreamliner™
Built on the success of the Trent family, the Trent 1000 offers airline operators a unique combination.
• Trent family experience
• Advanced technology
• Smart design
The move to a More Electric Engine
Trent 1000 – Tailored for the More Electric Aircraft
9
Unique to 3-shaft architecture
• Fuel savings on short range
• Best Compressor Operability
• Lower idle thrust
• Lower noise
Challenges surrounding Electrical to Mechanical stiffness
• Sustained Torsional oscillation
• Increased integration of
systems
The move to a More Electric Engine
Intermediate Pressure Power Off-Take
10
• Novel Starter Generator • Electrical Accessories • Electric Actuators • Advanced Bearings • Potential to remove the
Accessory Gearbox • Can be Bled or Bleedless
engine
The move to a More Electric Engine
Key technology components
11 The move to a More Electric Engine
The main challenges
Rolls-Royce Proprietary Information Page 11 of 5
Technology
• x1 order of magnitude for
Thermal Integration
• X2 order of magnitude for
Power Electronics
• X3 order of magnitude for
Technology
Risk
• Customer has zero tolerance to
programme delay
12
Potential targets
• Aircraft movements are emission-free when taxiing.
• Air vehicles are designed and manufactured to be recyclable.
• Europe is established as a centre of excellence on sustainable alternative fuels
Targets are for new aircraft and whole industry relative to 2000
Reduce fuel consumption and CO2 emissions by 75%
Reduce NOX emissions by 90%
Reduce perceived external noise by 65%
The move to the More Electric Engine & more!
Future Key driver – New ACARE Targets for 2050
13 The move to the More Electric Engine & more!
The S-Curve of Technology Cycles
14 Innovate UK DEAP Project
• Distributed Electrical Aerospace Propulsion (DEAP) is a 2-year
Innovate UK co-funded collaborative research project between:
- Airbus Group Innovations (Project Lead)
- Rolls-Royce Strategic Research Centre
- Cranfield University
- With the collaboration of Cambridge and Manchester
Universities
E-Thrust concept (shown at
Paris 2013 and Farnborough
2014 Air Shows)
15 Distributed Propulsion with Boundary Layer Ingestion
Distributed Propulsion Benefits
1. Maximises opportunity for BLI
2. Facilitates of installation of low specific thrust propulsion
3. Structural efficiency/optimised propulsion system weight
4. Minimises asymmetric thrust, reducing vertical fin area
5. Reduced jet velocity & jet noise
Benefit of BLI:
Improves overall vehicle propulsive efficiency
by reenergising low energy low momentum
wake flow
Page 18
Viscous drag build up with BLI(Cores under wing) CDviscous 47.4
CDviscous (upper) 26.3
CDviscous (ingested ) -10.67
CDviscous (slot) 2.3
CDfriction (upstream of slot) 7.8
CDviscous = CDfriction + CDform
Totals:
CDviscous 46.83
CDviscous -0.57
% Aircraft drag = -0.4%
Page 18
Viscous drag build up with BLI(Cores under wing) CDviscous 47.4
CDviscous (upper) 26.3
CDviscous (ingested ) -10.67
CDviscous (slot) 2.3
CDfriction (upstream of slot) 7.8
CDviscous = CDfriction + CDform
Totals:
CDviscous 46.83
CDviscous -0.57
% Aircraft drag = -0.4%
Conventional
Ideal BLI
16 Flight Cycle Benefits
A typical flight cycle can be characterised by its very asymmetric
form
Hybrid Systems could deliver benefits in the design of the
propulsion system by optimising the propulsion system for the
different requirements
17
E-Thrust Superconducting Machine
Magnetic “Pucks” on superconducting motor rotor
Electrical cables with concentric cryogenic cooling fluid
Superconducting motor stator
18 Challenge – High Power Airworthy Cryogenics
• There are no high power (>1 kW available cooling power) aerospace cryocoolers currently in existence
• Aerospace designs typically designed for IR missile sensors and satellite instrument cooling are in the multi-Watt range; Distributed Propulsion with superconducting technology will require multi-kilowatt capacity designs.
• Non-aerospace versions capable of delivering the cooling power required are very heavy and bulky.
• This design weighs 8 tonnes, and provides 25 kW of cooling power at 77 K
• At 1 MW required input power, the cooler has a specific mass of 8 kg/kW and an overall efficiency of just 2.5 %
• NASA have outlined goals to cut this down to below 3 kg/kW input.
