1. mission statement design requirements aircraft concept selection advanced technologies / concepts...
TRANSCRIPT
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Systems DesignReview
Dean Jones
Dustin Souza
Anthony Malito
Ricardo Mosqueda
Alex Fickes
Keyur Patel
Matt Dienhart
Danielle Woehrle
Nayanapriya Bohidar
N.E.R.D.New Environmentally Responsible Design
• Mission Statement
• Design Requirements
• Aircraft Concept Selection
• Advanced Technologies / Concepts
• Engine / Propulsion Modeling
• Constraint Analysis / Constraint Diagram
• Sizing Studies
• Initial Center of Gravity, Stability and Control Estimates
• Summary of Aircraft Concepts
Outline
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To design an environmentally responsible aircraft for the twin aisle commercial transport market with a capacity of 400 passengers, NASA’s N+2 capabilities, and an entry date of 2020-2025.
NASA’s N+2 technology benefits include:
• Reducing cumulative noise by 42 dB below Stage 4• Reducing take-off and landing NOx emissions to 75% below CAEP6 levels• Reducing fuel burn by 50%
– relative to “large twin-aisle performance” (777-200LR)• Reducing field length by 50% relative to the large twin-aisle
Mission Statement
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• Requirements• Threshold
Design Requirements
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Requirements Threshold Target Current
Cruise Mach 0.75 0.80 0.80
Range 3,000 nmi 4,000 nmi 4,000 nmi
Field Length(at sea level, MTOW) 8,300 ft 5,800 ft 6,500 ft
Field Length(@ 14K ft, +15°F) 18,000 ft 9,000 ft 11,100 ft
Fuel Burn* 33% reduction 50% reduction** -
NOx Emissions 50% below CAEP 6 75% below CAEP 6** -
Noise Reduction 32 dB cum. below Stage 4
42 dB cum. below Stage 4** -
Passenger Capacity 350 400 400
*Fuel burn reductions relative to B777-200LR** NASA ERA goal
Aircraft Concept Selection
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The “Pocket Protectors” (2 Variations UDF or GTF)
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Aircraft Concept Selection
Pros
• Increased aerodynamic efficiency for lower drag
• Decreased noise with engines mounted on top
• Lighter structure
Cons
• Increased manufacturing complexity
• Increased maintenance costs
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Aircraft Concept Selection
The “Side Part”
Pros
• Conventional design
• Decrease manufacturing cost
• Decrease maintenance cost
• Increase noise shielding
Cons
• Not as efficient as a Blended Wing Body design
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Aircraft Concept Selection
The “Suspenders”
Pros
• Semi-blended wing design
• Circular pressure vessels
• Maintenance and manufacturing complexity not as high as a BWB design
Cons
• Higher drag from increased surface area
Cabin Layouts
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The “Pocket Protectors”
The “Side Part” The “Suspenders”
Advanced Technologies
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Requirements UDF GTF Composites Wingtip Technology
Fly By Wireless
Trailing Edge Brushes
Electric Actuators
Laminar Flow Control
Active Noise Cancellation
Fuel Burn + + + + + - + +
Exterior Noise - + + + + +
NOX + +
Field Length
Empty Weight - - + - + - + - -
Cruise Speed -
Manufacturing Cost - - - - - -
Maintenance Cost - - - + - + - -
Pax/Crew Comfort - + +
Layout Complexity - - - -
Stability & Maneuverability
Minimum Ground Time
Aesthetics + + - -
Sigma -3 1 1 0 2 -4 3 -2 -3
Un-Ducted Fan (UDF)
• Offering minimal fuel consumption• Double digit SFC• 30% Reduction in fuel consumption and greenhouse gases• Offering speed and performance of a turbofan• Bigger in size, noisy, safety issues
Geared Turbofan (GTF)
• 12% reduction in fuel consumption• 35-50% reduction in CO2 and NOx• 50% reduction in noise• Bigger in size• Fuel consumption is an issue
Engine Concepts
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Rubber Engine Sizing
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Concepts T/TOGW Thrust Required TOGW EnginesRequired
Direct-Drive Engines
Required
Pocket ProtectorsWith UDF Engine 0.36 84837.6 235660.00 2.31 0.735798786
Pocket ProtectorsWith GTF Engine 0.28 75633.6 270120.00 2.06 0.655972246
Side Part UDF Engine 0.335 84406.6 251960.00 2.29 0.732060711
Suspenders UDF Engine 0.317 76977.1 242830.00 2.09 0.667624545
GTF(PW1400G @ 32K)
UDF(same as GTF)
Direct-Drive(GE90-115B)
36800 36800 115,300
50 60 70 80 90 100 110 120 130 140 1500
0.1
0.2
0.3
0.4
0.5
0.6
top of climb (1g steady, level flight, M = 0.8 @ h=34K, service ceiling)
sustained subsonic 2g manuever, 250kts @ h =10K
takeoff ground roll 4500 ft @ h = 5K, +15° hot day
landing braking ground roll 2000 ft @ h = 5K, +15° hot day
second segment climb gradient above h = 5K, +15° hot day
W0/S [lb/ft2]
TS
L/W
0
Constraint Analysis
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Constraint assumptions
L/D = 23.9CL max = 2.16CD0 = 0.0075
e = 0.9AR = 12
αcruise = 0.322αloiter = 0.739Vcruise = 0.8 M
VTO = 256.9 ft/sVapproach = 283.1 ft/s
Pocket Protector
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Altitude (ft) Mach Aspect
RatioTO Ground
Roll (ft)Braking Ground Roll (ft)
34000 0.8 12 4500 200034000 0.8 12 4000 200034000 0.8 12.5 4000 2000
Wo/S(lb/ft2)
TSL/Wo
115 0.27105 0.27100 0.26
Altitude(ft) Mach Aspect
RatioTO Ground
Roll (ft)Braking Ground Roll (ft)
34000 0.8 12 4500 200034000 0.8 12 5800 250034000 0.8 12.5 6000 2500
Wo/S(lb/ft2)
TSL/Wo
90 0.36108 0.36115 0.35
Pocket Protector
High Hot Operating Conditions : H = 14K + 15°
Constraint Analysis
Normal Operating Conditions
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Constraint assumptions
L/D = 19.7CL max = 1.8CD0 = 0.015
e = 0.8AR = 9
αcruise = 0.322 αloiter = 0.838 Vcruise = 0.8 M
VTO = 240.6 ft/sVapproach = 265.05 ft/s
50 60 70 80 90 100 110 120 130 140 1500
0.1
0.2
0.3
0.4
0.5
0.6
top of climb (1g steady, level flight, M = 0.8 @ h=34K, service ceiling)sustained subsonic 2g manuever, 250kts @ h =10Ktakeoff ground roll 5800 ft @ h = 5K, +15° hot daylanding braking ground roll 2000 ft @ h = 5K, +15° hot daysecond segment climb gradient above h = 5K, +15° hot day
W0/S [lb/ft2]
TS
L/W
0
Constraint Analysis
Side Part
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Altitude(ft) Mach Aspect
RatioTO
Ground Roll (ft)
Braking Ground Roll (ft)
34000 0.8 9 4500 2000
34000 0.8 9 4500 2300
34000 0.8 9.5 4500 2000
Wo/S(lb/ft2) TSL/Wo
108 0.33
120 0.33
115 0.32
Altitude(ft) Mach Aspect
RatioTO
Ground Roll (ft)
Braking Ground Roll (ft)
34000 0.8 9 4500 2000
34000 0.8 9 6000 2500
34000 0.8 9.5 6000 2800
Wo/S(lb/ft2) TSL/Wo
84 0.43
108 0.43
118 0.41
Side Part - Normal Operating Conditions
High Hot Operating Conditions- H = 14K +15°
Constraint Analysis
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50 60 70 80 90 100 110 120 130 140 1500
0.1
0.2
0.3
0.4
0.5
0.6
top of climb (1g steady, level flight, M = 0.8 @ h=34K, service ceiling)sustained subsonic 2g manuever, 250kts @ h =10Ktakeoff ground roll 4500 ft @ h = 5K, +15° hot daylanding braking ground roll 2000 ft @ h = 5K, +15° hot daysecond segment climb gradient above h = 5K, +15° hot day
W0/S [lb/ft2]
TS
L/W
0
Constraint assumptionsL/D = 21.8CL max = 2.45CD0 = 0.0138e = 0.75AR = 10.5αcruise = 0.323αloiter = 0.739Vcruise = 0.8 MachVTO = 260.9 ft/s @ sea levelVapproach = 268.1 ft/s @ sea level
Constraint Analysis
Suspenders
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Altitude(ft) Mach Aspect
RatioTO
Ground Roll (ft)
Braking Ground Roll (ft)
34000 0.8 10.5 4500 2000
34000 0.8 10.5 4000 2300
34000 0.8 12.5 4500 2000
Wo/S (lb/ft2)
TSL/Wo
117 0.32
105 0.32
107 0.28
Altitude(ft) Mach Aspect
RatioTO
Ground Roll (ft)
Braking Ground Roll (ft)
34000 0.8 10.5 4500 2000
34000 0.8 10.5 6000 4000
34000 0.8 12.5 4500 2000
Wo/S(lb/ft2)
TSL/Wo
92 0.41
125 0.41
85 0.35
Suspenders - Normal Operating Conditions
High Hot Operating Conditions- H = 14K +15°
Constraint Analysis
Sizing Study
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• Simple to Initial• L/D calculations implement results from trade studies• Component weight build-up method included in code
(Raymer, eqs.15.46 – 15.59)
• Component build-up technique underway for drag prediction
(Raymer, eq. 12.24)
• Best current predictions
Concepts TOGW (lb) OEW (lb) Wfuel (lb)
The “Pocket Protectors” 235,660 91,540 54,720
The “Side Part” 251,960 97,480 65,070
The “Suspenders” 242,830 94,160 59,270
•Validation
Sizing Study
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2,500 3,000 3,500 4,000 4,500 5,000 5,500100000.00
150000.00
200000.00
250000.00
300000.00
350000.00
400000.00
450000.00
500000.00
550000.00
600000.00
B737-700
B767-200
B777-200
Range Comparison
RangeLinear (Range)Pocket ProtectorsSide PartSuspenders
Range (nmi)
TOGW
(lb)
100 150 200 250 300 350 400 450 5000.00
100000.00
200000.00
300000.00
400000.00
500000.00
600000.00
B737-700
B767-200
B777-200
Passenger Comparison
PaxLinear (Pax)Pocket ProtectorsSide PartSuspenders
Pax
TOGW
(lb)
Center of Gravity Estimates
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Concept Center of Gravity (% a/c length)
Static Margin Threshold
Static MarginTarget
Pocket Protector 53% 5% 8%
Side Part 61% 5% 8%
Suspenders 59% 5% 8%
Control Sizing Approach
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• Tailless Concepts– Aerodynamic Center Location– Wing Sweep Tradeoffs
• Traditional Tail Concepts– Tail Area
• Implementing New Technologies
• Geometry Sizing
- Component weight distribution
- Drag build-up
• Stability Analysis
• Internal layout and subsystems
• Noise prediction
• Concept refinement
Next Steps
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