Group 1F Final Design Review

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Group 1F Final Design Review
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Contents of presentation

• PDR Review
• BWB Advantages
• Risks Identified
• Aerodynamics
• Stability
• Structures
• Materials
• Cargo Layout
• Performance
• Propulsion
• Noise and Emissions
• Systems
• Economics
• Family Concept
• Conclusion

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PDR Review

• Successive iterations
• Identification and tracking of risks

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BWB Advantages

• Economic
• 15 DOC improvement on A380F
• Fuel burn accounts for a lower proportion of COC
• Environmental
• Aerodynamically more efficient due to lower
  surface wetted area
• Structurally more efficient
• 86 Payload/OWE compared to 60 for A380F
• Reduced fuel burn hence lower emissions
• Society
• Wing shields engine noise from ground
• Lack of high lift devices reduces noise on
  takeoff and landing
• 15 dB noise reduction when compared to a standard
  configuration
• Future development
• Strategic advantage to company to have a BWB
  aircraft for future development of aircraft

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Risks identified

• Stability
• Reduced damping due to lack of empennage
• Difficulty controlling longitudinal moments
• Control
• Aerodynamic cross-coupling of control surfaces
• Large control surfaces hence large control
  surface moments
• Structures
• Pressure loads must be resisted in bending
• Fabrication complex geometries
• Extensive use of composites
• Low CL max
• Lack of flaps leads to a low CLmax high
  approach speed

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Tornado VLM

• Tornado Vortex Lattice Method
• MATLAB based invisid incompressible CFD program
• Prandtl-Glauert correction used for M gt 0.3
• Gives good estimates of aerodynamic forces,
  moments derivatives
• Enabled quick alterations of the design to be
  tested
• Empirical methods
• Used to find parasitic and wave drag, stall and
  buffet properties
• Reality check results produced by Tornado

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Aerofoil selection
Inboard Modified Eppler 339

• Reflex aerofoil
• Negative camber at rear improves stability
• t/c modified to increase internal capacity
• Compromise between lift, interior capacity

Outboard NACA(2)0410

• Supercritical aerofoil
• Good high speed performance
• High Cl and low Cd
• Good buffet characteristics
• Delays onset of transonic effects

Reflex
Supercritical
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Aerodynamic performance

• Elliptical lift distribution minimised induced
  drag
• Triangular lift distribution minimised wave drag
• Compromise between distributions

Lift distribution
Cruise L/D 22.5
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Stability

• A BWB design has inherent stability issues both
  longitudinally and laterally by virtue of being a
  tailless aircraft

• Major design driver Statically Stable

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Stability

• A BWB design has inherent stability issues both
  longitudinally and laterally by virtue of being a
  tailless aircraft

• Major design driver Statically Stable

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Stability

• A BWB design has inherent stability issues both
  longitudinally and laterally by virtue of being a
  tailless aircraft

• Major design driver Statically Stable

• Wings moved forward
• Sweep added sweep

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Stability
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Stability
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Dynamic Stability
Side Slip due to Aileron deflection
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Dynamic Stability
Response
Time (s)
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Structures

• Non-cylindrical Fuselage requires pressure loads
  to be carried in bending
• Fuselage idealised as section from a single cargo
  row
• FE Analysis of different structural
  configurations was carried out

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Structures

• Curved pressure barriers selected for weight,
  robustness and lower deflection, despite greater
  manufacturing difficulties
• Fuselage is built around this cellular concept
• Diffusive wing joint results in a lower overall
  airframe weight than conventional aircraft,
  despite extra fuselage structure.

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Structures

• Conventional internal wing structure
• Leading edge used as a pressure barrier
• Rear wing spar and fuselage frames take landing
  gear loads
• Pressure fuselage, aft fuselage and wings
  assembled separately

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Materials

• CFRP Fuselage to reduce fatigue penalty
• CFRP Wing
• Carbon Fibre/Aluminium Joints avoided where
  possible

CFRP Sandwich CFRP Laminate Titanium
Alloy Fiberglass Aluminium
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Landing Gear

• 6446 Main Gear Configuration
• Margin for 20 heavier derivative

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Cargo Layout
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Weights and Balance
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Take-off Performance
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Performance
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Performance
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Engine Integration
10o
Cascade thrust reverser
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Noise

• Engines
• Wing shielding
• High BPR
• Chevrons
• Advanced acoustic liners
• Rotor Sweep

• Airframe
• Landing gear fairings

• Operations
• Continuous Descent Approach

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Emissions
Lean Pre-mixed Pre-vaporised (LPP) Combustor
Main
Pilot
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Systems Architecture
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System Control
Data and DC Routers
Main Core
Hazard Control Computer
Low Speed Data Links (1-100Kb/s
Backup Core
MIL-C-26482 - 12-10 For fast and reliable
connection
High speed Data Links (1Gb/s)
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Fuel Systems
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Power Systems
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Economics
Non-recurring Costs 23,336 M
Profit per a/c 77.29 M
Manufacturing costs 227.56 M
Acquisition Price 304.8 M
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Economics
More efficient COC distribution ? 22.9 COC
reduction
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Economics
15.2 DOC Reduction
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Economics
16.3 DOC Reduction
16.3 DOC Reduction
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Economics
747-8F
A380-F
747-400F
BWB
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Family Concepts

• Systems redesign minimal
• Structural redesign restricted to middle section
• Less commonality between the derivatives
• To increase payload by 20
• Breach Code-F Regulation
• Current landing gear sized for larger derivative
• Stability augmentation may be necessary
• Fourth engine needed
• To decrease payload by 20
• Change to centre structure necessary

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Conclusions

• There are challenges associated with Blended Body
  aircraft
• These challenges have been met and we have
  designed a viable aircraft which meets the
  specification
• The G1F-BWB is
• Quiet
• Environmentally friendly
• Highly efficient
• Low Direct Operating Costs
• The G1F-BWB will revolutionise the freighter
  market

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• THANK YOU