Future Aerospace Technologies
Jon Clare
Professor of Power Electronics
Director of GE Aviation SMARTPACT UTSP
Some Key Activities in Engineering
at Nottingham
• Rolls Royce UTC in Gas Turbine Transmissions
• Advanced Manufacturing Technology
– Precision Manufacturing Centre (PMC)
• Centre of Excellence for Customised Assembly (CECA)
• Composite Materials
• George Green Institute for Electromagnetic Research
• Non-destructive Evaluation
• More Electric Aircraft
– Power Electronics, Machines and Control Group
– GE Aviation UTSP in Advanced Electrical Power and Actuation
• Total portfolio of Aerospace Research in Engineering > £30M
Rolls-Royce UTC in Gas Turbine
Transmission Systems
• UTC founded in 1997 – led by Professor Tom
Hyde (Mechanical, Materials & Manufacturing
Engineering)
• Currently employs 9 research fellows and 19
postgraduate researchers
• 17 academics involved from three schools across
the Faculties of Science and Engineering
• Funding income from a mixture of TSB, EU,
EPSRC and Industry
Rolls-Royce UTC in Gas Turbine
Transmission Systems
• Three main areas of research relating to transmissions,
structures, dynamics and fluids (oil system)
• Example activities include:
– new advanced materials, novel designs for shafts, couplings,
support structures and casings,
– dynamic behaviour of high performance gearboxes
– performance of the oil systems and the design of seals to
prevent oil leaking from the transmission system.
Rolls-Royce UTC in Gas Turbine
Transmission Systems
Geometry definition
Loading definition:
Major & minor cycles
• Characterisation of aeroengine transmissions
materials and components for fretting wear and
fatigue
Automated spline
meshing tool
Material and surface
properties:
 Fatigue parameter
 Wear coefficient
 Friction Coefficient
ABAQUS
FE analysis
• Development of simplified ‘look-and-see’ tests for
complex applications, e.g. splines under multiaxial
loading
Post-processing
prediction tools
Plain Fatigue
()
• Development of validated computational method
for prediction of fatigue, fretting fatigue and wear
in simple and complex aeroengine components
and materials
Fretting damage
(, )
Fretting
Wear
Fretting
Fatigue
Multiple, parallel
45o plain fatigue
cracks
Axial Load
Tooth
18
Fd
1
Tooth
1
Tooth
2
Tooth
3
Spline plain fatigue failure
Step
Torque
2
Tmax
Tmean
Tmin
Step
Bending
Load
+B
B2
Spline fretting fatigue failure
3
Step
B1
-B
1
2
3
4
5
6
Advanced Manufacturing
Technology
Led by Professor Svetan Ratchev & Professor Nabil Gindy
(Mechanical, Materials & Manufacturing Engineering)
Research areas include:
Polymer composites
Intelligent process monitoring & control
Laser processing
Metal deposition
Conventional and unconventional machining
Precision assembly
Large scale assembly
Partners include:
Airbus UK, Alsthom, BAE Systems,
Bombardier, Boeing, Bosch, EADS, Ford, GE
Aerospace, Matra BAE Dynamics, Rolls-Royce,
Siemens
Advanced Manufacturing
Technology
Large Scale Assembly
• Assembly and joining of large aircraft
structures
• Distributed network based control
system
 Inbuilt intelligence for task optimisation
 Does not require fixtures and reference
points
 Supports integration of multiple
metrology and robot systems
Advanced Manufacturing
Technology
Precision Manufacturing
Centre (PMC)
World-class centre of research centre in:
• High Precision Manufacturing/Assembly
• Reconfigurable Assembly Systems
• Active Fixturing Systems
• Manufacturing Process Modelling
• Product to Service Transformation
Collaborations include (not exhaustive):
• Rolls Royce, BAE Systems, EADS, MBDA
Missile Systems, Volvo Aerospace, Philips,
Electrolux, GlaxoSmithKline, AstraZeneca,
Unilever, Sun Microsystems, Bosch
• Includes Centre of Excellence in Customised
Assembly (CECA)
Project portfolio in excess of £2.5 Million
Our Know-How
Your Advantage
Composite Materials
• Led by Professor Andy Long (Mechanical,
Materials & Manufacturing Engineering)
• Polymer Composites Group focus on economic
(out-of-autoclave) manufacture, mechanical
performance and recycling.
• Key focus of aerospace work is on “Textile
Composites”
• Research team of around 45 staff/students, with
a current grant portfolio of ~£5M.
Composite Materials
“Virtual testing” for textile composites
Reinforcement model
generated using our TexGen
schema & used for predictive
modelling of composites
processing and performance
Dry fabric/prepreg mechanics
- To predict material formability
Resin flow/permeability
-To enable simulation of
resin infusion
http://texgen.sourceforge.net
Composite mechanical properties
Composite Materials
3D woven reinforcements for aerospace composites
Ave. Stress (GPa)
These offer significant benefits including:
• enhanced delamination resistance & damage tolerance
• automated manufacture of “thick”, reinforcements with
complex geometries
0.1
0.09
0.08
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0
Resin failure
Weft
Warp
Through thickness
Warp/weft
failure
Binder failure
0
0.001
0.002
0.003
0.004
0.005
0.006
Applied Strain
Unit cell FEA with continuum damage model to
predict stress-strain up to final failure
Carbon multilayer structure
with integral pockets
Carr Reinforcements Ltd
“TexGen” model of
orthogonal weave
unit cell
0.007
George Green Institute for
Electromagnetic Research (GGIEMR)
• Led by Prof Christos Christopoulos
(School of Electrical and Electronic
Engineering
• 50 researchers, £1M funding per
annum
• Aerospace activities include:
– FLAVIIR (BAES/EPSRC)
– MOET (Airbus/EU)
– Marie-Curie (THALES/EU)
– HIRF SE (Alenia/EU)
GGIEMR – Technical Areas
• Characterization of EM
environment through
measurements and
simulations
• Establishment of
performance criteria for
immunity and emissions
• Signal integrity and
functional performance
• Intra-system noise and its
impact on data transmissions
• Impact of modulation and
coding on system
performance
GGIEMR Example - Towards a
Wireless Aircraft
• Copper weight in modern military aircraft
600-1000 kg
• 2-engine wide-body civil aircraft: 81miles
• 4-engine large civil aircraft: 329 miles
• Disadvantages
–
–
–
–
complexity
vulnerability
lack of flexibility
most of the time wires carry no signals!
• Research
– Can we use wireless channels on which we
multiplex a multitude of data to be
distributed throughout the aircraft?
• Technical issues
– costs, security
– Hybrid systems: mix of copper, wireless,
fibre etc
Non-destructive Evaluation
• Applied Optics Group, School of Electrical and
Electronic Engineering
–
Prof Mike Somekh, Dr Matt Clark, Prof Richard
Challis
• Cheap Optical Transducers (CHOTS – laser
ultrasound)
–
–
Application to analysis of microstructures and
defects in inaccessible areas (eg turbine blades)
Robust, cheap and remote communications
• Group hosts the UK Centre for Non-destructive
Evaluation
–
Location and characterisation of micro-porosity in
carbon-fibre reinforced composite structures
(Airbus)
Surface picture of 45mm2 area of a
titanium alloy.
Colour scale indicates the phase
velocity of the Surface Acoustic
Waves.
More Electric Aircraft (MEA) Research
• Power Electronics, Machines and Control Group
– Led by Prof Jon Clare
– Group of 90 researchers, £9.5M research portfolio
• Major MEA activities
– GE Aviation/EPSRC Strategic Partnership in “Advanced Electrical Power
and Actuation”
• Director Prof Jon Clare
• Collaboration with Heat Transfer Group (M3) and Warwick
– MOET EU FP6 Project
• Nottingham activity led by Prof Patrick Wheeler
• Collaboration with Heat Transfer Group (M3) and GGIEMR
– CLEAN SKY EU FP7 “Joint Technology Initiative”
• Nottingham are “Associate Members” led by Prof Patrick Wheeler
• Collaboration with Heat Transfer Group (M3) and GGIEMR
• Expected project budget circa £8M at Nottingham (50% funding)
– BOEING
• Power conversion research
• Total portfolio of Aerospace activities > £6M
Power Sources – “Conventional”
Aircraft
Jet Fuel
Propulsion
Thrust ( 40MW)
Gearbox driven
generators
Electrical
200kW
High pressure
air “bled” from
engine
Gearbox driven
hydraulic pump
Pneumatic
Hydraulic
1.2MW
240kW
Total “non-thrust” power  1.7MW
Fuel pumps
and oil pumps
on engine
Mechanical
100kW
Power Users – “Conventional”
Aircraft
– Electrical
• Avionics
• Cabin (lights, galley, in-flight entertainment
etc)
• Lights, pumps, fans
• 115V, 400Hz AC
– Pneumatic
• Cabin pressurisation
• Air conditioning
• Icing protection
– Hydraulic
• Flight control surface actuation
• Landing gear extension/retraction and
steering
• Braking
• Doors
– Mechanical
• Fuel and oil pumps local to engine
“More Electric Aircraft” Concept
Jet Fuel
Rationalisation of
power sources and
networks
Propulsion
Thrust
“Bleedless” engine
Engine driven
generators
Existing electrical
loads
ELECTRICAL
Cabin pressurisation
Air conditioning
Icing protection
Expanded electrical network
ELECTRICAL
Flight control actuation
Landing gear/ Braking
Doors
New electrical loads
Electrical system power  1MW
ELECTRICAL
Fuel pumping
Engine Ancillaries
“More Electric Aircraft” – Some
Motivations
– Removal of hydraulic system
• reduced system weight
• ease maintenance
– “Bleedless” engine
• improved efficiency
– Desirable characteristics of electrical systems
• controllability
– power on demand
• re-configurability
– maintain functionality during faults
• advanced diagnostics and prognostics
– more intelligent maintenance
– increased aircraft availability
• OVERALL
– Reduced operating costs
– Reduced fuel burn
– Reduced environmental impact
Some MEA Research Themes
• Aircraft Electrical Power System Design
• Power Conversion
• Actuation Systems
• Advanced Switching Technologies
• Heat Transfer Technologies
Aircraft Electrical Power System
Design
CHALLENGES
ISSUES
– Up to 10 times increase in
electrical power with MEA
– Optimum system
configuration
– Reliability/Availability
SG1
HVAC 1-1
ATRU 1
11
HVAC 2-3
HVAC 1-2
WIPS 1
ATU 1
11
ATRU 2
MCU 1
11
BBCU 1
11
28V DC
Loads
MCU 2
MCU 3
ECSM2
ECSM3
BBCU 2
11
BCRU 2
11
DC ESS 1
DC ESS 2
ETOPS 1
HOT ESS 1
SHD E-DC-1
ETOPS 2
HOT ESS 2
SHD E-DC-2
BAT 3
MCU 4
11
ECSM4
28V DC
Loads
AC ESS 2
AC ESS 1
BAT 2
ATRU 4
11
HVDC 2-4
HVDC 2-3
BCRU 1
11
BAT 1
WIPS 2
115V AC
Loads
HVDC 1-2
ECSM1
HVAC 2-4
ATU 2
11
ATRU 3
115V AC
Loads
HVDC 1-1
SG4
SG3
SG2
BAT 4
– Transient effects due to
large loads
– Stable operation
– Generation technology
– Power quality
– AC or DC system?
– Voltage level
– System topology
– System weight
– Operation with faulted
sub-system
– Maintenance
Aircraft Electrical Power System
Design
500
RESEARCH EXAMPLES
studies
• Architecture studies
– System operation
• Intelligent load management
• Re-configurability
– Diagnostics and Prognostics
• Component level
– Power semiconductors
• Equipment level
– Motor drives
• System level
• Intelligent maintenance
400
350
Capacitance (uF)
– Modelling and analysis
• Electrical system modelling
• Stability and power quality
0 Hz
450
100 Hz
200 Hz
300 Hz
400 Hz
Stable Region
900 Hz
300
250
200
Unstable Region
150
100
Blue: AC Distribution System
Red : DC Distribution System
50
0
0
50
100
Power (kW)
150
Aircraft Electrical Power System
Design
Aircraft systems reliability & availability - Aircraft operators and end
users are demanding increasing levels of reliability and availability resulting in
lower operating costs. Measuring and predicting the health of electrical power
systems is critical to this objective
CHALLENGES
– Failures are easy to identify
– Impaired functionality
(health) is less easy to
measure
OPPORTUNITIES
– Development of algorithms
to measure health of
components and systems
– Development of methods to
predict expected life of
components and systems
Power Conversion
CHALLENGES
– Generated electrical power
characteristics do not match
the load requirements
– Power conversion needed for
matching
– All electrical power (>1MW)
must
be processed at least once by
“Power Electronics”
– Power Electronics is a key
enabling technology
GENERIC ISSUES
– Power density
• Impacts equipment weight
– Reliability and fault tolerance
• Flight critical loads
– Efficiency
• Impacts on weight and fuel
– Cooling (thermal management)
• Critical issue for reliability
and weight
Power Conversion
CHALLENGING APPLICATIONS
– New high power electrical loads
• Environmental control system
(>100kW)
– New flight critical electrical loads
• Primary actuation
• Landing gear extension and
retraction
• Fuel pumping
RESEARCH EXAMPLES
– New power converter
technologies
• Higher power density
• High reliability
– Power quality
• Active filtering
– Mechanical and thermal
integration
• Power converter/load
integration
• Optimised system weight
Actuation Systems
CHALLENGES
– Elimination of hydraulics
• Electro-Mechanical Actuators
– High reliability
• Flight critical applications
– Intermittent operation
– System weight
RESEARCH EXAMPLES
– Novel electrical motors
• New topologies/materials
• High power/torque density
• Optimised for application
– Optimum integration of motor
and load
• Elimination of gearboxes
• Reduction of weight
– Advanced thermal management
• Cope with intermittent operation
– Holistic design of
motor/load/power converter
• Maximise system efficiency
• Minimise system weight
Advanced Switching Technologies
& Heat Transfer Technologies
Solid State Switching - The application of solid state based switch
technology to replace electro-mechanical technology provides many benefits but
also presents design challenges
CHALLENGES
– Fault current performance
– Switching density volume, weight and
thermal performance
OPPORTUNITIES
– Application of emerging
semiconductor technologies
– Development of improved
silicon level and device level
thermal management
solutions
– Replacement of electromechanical contactors with
solid state devices
– Reduction in aircraft cooling
requirements
Summary
• Nottingham has an extensive portfolio of World Class
research developing Future Aerospace Technologies
• Industrial partnerships are a vital aspect of the research
• Partners range from large global companies to SMEs
• Research is multi-disciplinary with strong collaboration
between Schools and with other academic partners
• The UNTR and other recent initiatives will provide
increased focus, cohesion and identity for Aerospace
Research across the University
• This presentation has hopefully given an impression of the
breadth and strength of Aerospace Research in
Engineering – but is not exhaustive!