logan waddell morgan buchanan erik susemichel aaron foster craig wikert adam ata li tan matt haas 1
Post on 19-Dec-2015
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ASGARD AVIATION CONCEPTUAL DESIGN
REVIEWLogan WaddellMorgan BuchananErik SusemichelAaron Foster
Craig WikertAdam AtaLi TanMatt Haas
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Outline1. Project mission2. Selected concept3. Sizing code results
• Modeling assumptions
4. Major Design Tradeoffs• Carpet plots
5. Aircraft description6. Aerodynamics
• Airfoil selection• High-lift devices
7. Performance• V-n diagram
8. Propulsion• Engine description
9. Structures• Configuration layout
10.Weights and Balance• Center of gravity location
11.Stability and Control12.Noise13.Cost14.Summary
3
Mission Statement
To design an environmentally responsible
aircraft that sufficiently completes the “N+2”
requirements for the NASA green aviation
challenge.
4
Major Design Requirements
Noise (dB) 42 dB decrease in noise
NOx Emissions 75% reduction in emissions below CAEP 6
Aircraft Fuel Burn 50% Reduction in Fuel Burn
Airport Field Length 50% shorter distance to takeoff
*
*ERA. (n.d.). Retrieved 2011, from NASA: http://www.aeronautics.nasa.gov/isrp/era/index.htm
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Selected Concept
Twin-aisle configuration, ~250 passengers with a two-class configuration
Wing loading: 108 lb/ft^2
Wing AR: 7.8
Wing sweep: 31˚
T/W: 0.32
6
Aircraft Concept Walk-around
Spiroid Winglets
Technology Suite
Geared Turbo Engines
Scarf Inlets
Chevron Nozzle
Landing Gear Fairings
Advanced Composites
Spiroid Winglets
Hybrid Laminar Flow ControlConventional VerticalStabilizer
Advanced Composite Materials
Wing Mounted Engines
7
Sizing Code Using MATLAB
software, first order method from Raymer
Used inputs to determine the size of pre-existing aircraft for validation
8
Incorporating Drag Drag values affect
fuel fraction weights which affect the fuel weight
Drag buildup equation used to predict drag
Wave drag uses Lock’s fourth power law
Included in the equation are the parasitic, induced, and wave drag
9
Component Weights
Component Weight (lb)
Fuselage 45,723
Wings 51,396
Vertical Tail 2,224
Horizontal Tails 5,494
Engines 25,200
Main Landing Gear 14,972
Nose Landing Gear 2,641
Empty weight buildup from Raymer text.
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Validation
Boeing 767-200ERPassenger
Capacity: 224Range: 6,545 nmiCrew: 2Cruise Mach: 0.8Max Fuel Capacity:
16,700 gal
11
Validation continued
Actual Prediction % Error
Gross Takeoff Weight
395,000 [lb] 426,560 [lb] 7.99
Empty Weight Fraction
.46684 .45765 1.97
The sizing code predictions are accurate
The error factor for the takeoff weight is:
12
Selected Concept Predictions
Take Off Gross Weight [lb]
Empty Weight Fraction
Wempty [lb] Wfuel [lb] Wpayload [lb] Wcrew [lb]
309050 .478 147650 105000 55000 1400
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Fixed Design Parameter Values
Parameter Value
Cd0 0.0198
Cl (cruise) 0.5185
L/D (cruise) 15.4654
Thickness to Chord Ratio
Sweep angle 31
14
Engine Modeling
ሺ𝑻𝑺𝑳𝑺ሻ𝒓𝒖𝒃𝒃𝒆𝒓 = (𝑾𝟎 )𝒓𝒖𝒃𝒃𝒆𝒓 [ሺ𝑻𝑺𝑳𝑺ሻ(𝑾𝟎 ) ]𝒏𝒆𝒏𝒈𝒊𝒏𝒆 𝑺𝑭= 𝑻𝑺𝑳𝑺ሺ𝑻𝑺𝑳𝑺ሻ𝒃𝒂𝒔𝒆𝒍𝒊𝒏𝒆
Used NASA Geared Turbofan tabular data to scale engine to desired propulsion characteristics
Scale factor is based on SLS thrust from tabular data Scale factors also implemented for technologies
Concept AircraftMTOW
(lbs)TSL/W0
# of engines
Max SLS Thrust (lbf)
Scale Factor
Baseline CS300ER 139600 0.335 2 23369 n/a
1Conventional
w/tech 309050 0.32 2 49448 2.116
2 H-Tail 316240 0.35 2 55342 2.368
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Engine Modeling Scale Factor used to size up all
performance data in NASA fileEx.
Technology Data AdjustmentOrbiting Combustion Nozzle
Performance Characteristic Adjustment FactorNOx Emissions 0.75Fuel Burn 0.85
𝑺𝑭𝑪𝒓𝒖𝒃𝒃𝒆𝒓 = 𝑺𝑭𝑪𝒃𝒂𝒔𝒆𝒍𝒊𝒏𝒆(𝑺𝑭)−.𝟏
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Design Mission
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Typical Design Mission
Average flight in the continental United States is 650 nm
Typical design missionChicago to New YorkApproximately 618 nmConnects two major citiesTypical route carries 212 passengers
○ 85% load factor
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“Basic” Carpet Plot
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Constraint Cross PlotsTakeoff Ground Roll(dTO < 5000 ft) Cross Plot
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Constraint Cross PlotsLanding Braking Ground Roll(dL < 2000 ft) Cross Plot
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Constraint Cross PlotsTop Of Climb (TOP >= 100 ft/min) Cross Plot
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Final Carpet Plot
Design Point W/S[lb/ft^2] T/S W0
108 0.32 309050
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Other Trade-offs
Geared Turbofan: Less Fuel Weight vs. More Drags
Hybrid Laminar Flow Control: 12-14% Less Drags vs. 2.8% More Cost
Landing Fairing: Reduce noise vs. More Weight
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•Length: 180’ 186’•Wing Span: 167’ 197’•Height: 51’ 56’•Fuselage Height: 17’ 19’ 7’’•Fuselage Width: 16’ 18’ 11’’
787-8Our concept
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Two Class System
Seating4 rows 1st Class34 rows Economy
Class250 passengers
Seat Pitch39 inches 1st Class34 inches Economy
Class Seat Width
23 inches 1st Class19 inches Economy
Class
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One Class System
SeatingNo First Class
(Low Cost Carriers)44 rows Economy
Class303 passengers
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Airfoil Selection Supercritical airfoils to be used for all
wing and stabilizer sectionsStill used for transonic aircraft*Reduce wave dragIncrease fuel storage space
Airfoil would be designed to meet design goalsCruise CL = 0.5185, L/D = 15.4654
*http://adg.stanford.edu/aa241/intro/futureac.html
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Divergent Trailing Edge Airfoil
Separation bubble employed to generate more lift at trailing edge
New technology being developed with advances in CFD Not much concrete data at this time
Potentially plausible for N+3 goals
http://adg.stanford.edu/aa241/intro/futureac.html
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High-Lift Devices
Slats, Triple-slotted flapsUsed for reliability
Lift coefficients for different configurationsTakeoff CL = 1.3Landing CL = 2.5
Landing and takeoff speeds set at 175 mph (152 kts), 15% faster than stall
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Performance
V-n (Loads) Diagram
Performance Summary
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V-n (Loads) Diagram
n=+2.11n=-1
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Performance Summary
Performance Summary Values
Best Range Velocity 473 knots
Best Endurance Velocity 412 knots
Stall Speed 132 knots (no flaps)
Maximum Speed during Climb
191 knots
Maximum Speed during Cruise
M = 0.8
Takeoff Distance (ground roll)
4,500 ft
Landing Distance (ground roll)
1700 ft
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Propulsion Engine type: High-Bypass Geared Turbofan
Bypass Ratio: 14.5-14.7 Fan Pressure Ratio: 1.4-1.6 Overall Pressure Ratio: 42 SLS Thrust: 49,450 lbs Dry Weight: 9590 lbs
Improvement Technologies Orbiting Combustion Nozzle
Improves fuel burn/reduces emissions Scarf Inlet
Redirects/Decreases fan noise Chevron Nozzle
Reduces low frequency exhaust noise
Courtesy of Airliners.net
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Other Technology Effects
Chevron Nozzle Mixing flows can have adverse effect on thrust
Scarf Inlet Greatly increases engine nacelle weight Reduces inlet efficiency
Orbiting Combustion Nozzle Thrust does not take a huge hit due to
converging/diverging exit Lack of need for diffusers and stators on either
end of compressor reduce weight of engine
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Engine Performance Specific Fuel Consumption
0 0.1 0.2 0.3 0.4 0.5 0.60
0.050.1
0.150.2
0.250.3
0.350.4
0.450.5
Full Throttle Sea Level SFC
NASA Data
Rubber Engine
Rubber w/Tech
Mach Number
SF
C (
1/h
r)
0.5 0.55 0.6 0.65 0.7 0.75 0.8 0.850.3
0.35
0.4
0.45
0.5
0.55
Partial Throttle Cruise SFC
NASA Data
Rubber Engine
Rubber w/Tech
Mach Number
SF
C (
1/h
r)
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Engine Performance
500.00 550.00 600.00 650.00 700.00 750.00 800.000.00
2000.00
4000.00
6000.00
8000.00
10000.00
12000.00
14000.00
16000.00
18000.00
Available vs. Required Thrust (35k feet)
Thrust Available
Thrust Required
Polynomial (Thrust Required)
Velocity (ft/s)
Th
rus
t (l
bf)
450.00 550.00 650.00 750.00 850.000.00
5000.00
10000.00
15000.00
20000.00
25000.00
Available vs. Required Thrust (30k feet)
Thrust Available
Thrust Required
Polynomial (Thrust Required)
Velocity (ft/s)
Th
rus
t (l
bf)
0.00 100.00 200.00 300.00 400.00 500.00 600.000.00
10000.0020000.0030000.0040000.0050000.0060000.0070000.0080000.0090000.00
100000.00
Available vs. Required Thrust (Takeoff)
Thrust Available
Thrust Required
Velocity (ft/s)
Th
rus
t (l
bf)
0.00 100.00200.00300.00400.00500.00600.000.00
50000.00
100000.00
150000.00
200000.00
250000.00
Available vs. Required Thrust (Landing)
Thrust Available
Thrust Required
Velocity (ft/s)
Th
rus
t (l
bf)
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Engine Performance Emissions Reduction/Fuel Burn Savings
LTO NOx Emissions
CAEP 6 Standard 83 g/kN
75% below CAEP 6 20.75 g/kN
Original Engine Deck 54 g/kN
% Improvement 34.9%
Rubber Engine 21.1 g/kN
% Improvement 74.6%
Fuel Burn (Cruise)
RB-211 (757) 7023 lb/hr
Rubber GTF Engine 3841 lb/hr
% Reduction 45.31%
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Structures: Load Paths
•Wing-fuselage intersection (Wing box)
•Pylons
•Tail Intersections
•Fuselage
•Landing gear
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Structures: Wing Box
Wing-fuselage intersection (Wing box)
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Structures: Engine Pylons
Engine pylons
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Structures: Landing Gear
Landing Gear Integration
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Structures: Material Selections
Composite Fuselage
(Carbon Laminate)
Composites on leading edges for laminar flow
Aluminum and Fiberglass wings
Titanium for pylons
Steel for elevator, rudder, and landing gear
Total MaterialsCompositesAluminumTitanium Steel
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Weights and Balance
Aircraft Group Weights Statement
Description of Empty Weight Prediction
Location of Center of Gravity
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Empty Weight Prediction Method Equations for a/c components from
Raymer Each component function of designed
gross weight Summation of component weights
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CG and Neutral Point
Center of Gravity: Components included in CG calculation
Fuselage, wing, horizontal tail, vertical tail, nacelles, engines, and landing gears
Other weights put in center of vehicle Crew, passengers, payload, furnishings,
etc. Neutral Point: 87.6 ft from nose
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Center of Gravity Travel
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Stability and Control
Static Longitudinal Stability Lateral Stability
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CG and Longitudinal Stability
CG from Nose [ft] Weight [lb] Static Margin
EW 84.32 147650 14.6%
OEW 84.0 214550 16%
OEW+fuel 82.18 254050 24.1%
MTOW 83.30 309050 19.1%
MTOW-fuel 85.46 204050 9.5%
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Tail Sizing
Current ApproachUsing Raymer Equations (6.28) and (6.29)
Concept 1
Tail area 815 ft2
Vertical Tail area 660 ft2
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Control Surface Sizing
Control Surface
Surface Area [ft2]
Aileron 476
Elevator 149
Rudder 198
Raymer Figure 6.3 – Aileron Sizing Raymer Table 6.5 – Elevator Sizing
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Noise Reduction Technologies
Geared turbofan engine Approximate 20% in noise Engine developed twice as powerful as anything presently built,
10% reduction in noise used Compared to Boeing 777-200ER with GE 90-90B engines, this
is a 9 dB decrease Chevron nozzle
Reduces noise up to 2.5 dB Due to engine size, reduction assumed to be 1 dB
Scarf Inlet No concrete data could be found, noise reduction assumed to
be 1 dB Landing Gear Fairings
Reduce noise by 2 dB
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Boeing 777-200LR Noise Data
http://adg.stanford.edu/aa241/noise/noise.html
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Conclusion on Noise For Stage 4 standards, noise generated must be
less than 90 dB in any given test. To meet N+2 requirements, the cumulative margin
between the noise generated and 90 dB must be at least 42 dB.
Estimates give a 9 dB deficit from Stage 4, with a cumulative noise reduction of 27 dB. Goal is NOT met.
Plenty of noise reduction technology is in development, but none would be ready by 2025.
54
Cost Prediction* the accuracy of results obtained with these models for commercial aircraft is questionable
0 50 1001502002503003504004500
1000
2000
3000
4000
5000
6000
Airframe cost (RDT&E)
Airframe cost (RDT&E)
Number of aircraft produced
Co
st p
er A
ircr
aft
(Mil
lio
ns)
Non-Recurring Costs• Engineering• Tooling• Development support• Flight tests
Recurring Costs• Engineering• Tooling• Manufacturing• Material• Quality Assurance
•Increase cost by ~ 20% to account for all new technologies
* Analysis from NASA Airframe cost model
Airframe cost in 2011$, millions
# A/c Non-recurringRecurring cost Total Cost Cost per A/C
1 4495.35 1147.7 5643.05 5643.0510 4495.35 3561.55 8056.9 805.6950 4495.35 7981 12476.35 249.527
100 4495.35 11382.7 15878.05 158.7805200 4495.35 16350.7 20846.05 104.23025400 4495.35 23703.8 28199.15 70.497875
1000 4495.35 39477.2 43972.55 43.97255
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Cost Prediction
Example case if producing 200 A/C
Would have to sell each aircraft for $104M to break even
Using the modified DAPCA IV Cost Model (costs in 2011 dollars)*Increased cost by 20% to account for technologies
•Production of 200 aircraft
•RDT&E + Flyaway = $34.1208 B
•Would have to sell 200 aircraft for $170.6 M each to breakeven
Airframe cost
# A/c Non-recurringRecurring cost Total Cost Cost per A/C
1 4495.35 1147.7 5643.05 5643.0510 4495.35 3561.55 8056.9 805.6950 4495.35 7981 12476.35 249.527
100 4495.35 11382.7 15878.05 158.7805200 4495.35 16350.7 20846.05 104.23025400 4495.35 23703.8 28199.15 70.497875
1000 4495.35 39477.2 43972.55 43.97255
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Cost: Operations and Maintenance
• Fuel costs Price: ~$5.50 / gallon Jet A (2011 price)
•Crew Salaries
•Maintenance
•InsuranceCommercial: add approx. 1-3% to cost of operations *Raymer
•Depreciation~ 4.0% total value per year
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Cost: Operations and MaintenanceIn 2011$
Cockpit Crew: $912.66 /block hour (domestic) $1003.15 / block hour (international)
Cabin crew: ~$647.14 /block hour (domestic) ~$841.07 / block hour (international)
Landing fee: $679.5 / trip
Maintenance labor: 3.64 MMH/FH airframe 6.84 MMH/TRIP Engine
Maintenance material: $85.74/ flight hour airframe $1416.12/trip Engine
* Advanced subsonic Airplane design & Economic Studies (NASA)
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Summary of Final Design
•Tube and Wing design with advanced technologies•Swept back wings• Technologies
• Spiroids• Laminar Flow• Geared Turbofan• Composite Materials
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Compliance MatrixDesign
Requirements Units Target Threshold Final Design Compliant
Range Nautical Miles
4,000 3,600 4,000 Yes
Payload Passengers 250 230 250 Yes
Cruise Mach # - 0.8 0.72 0.8 Yes
Takeoff Ground Roll
ft 7,000 9,000 4,500 Yes
Landing Ground Roll
ft 6,000 6,500 1,700 Yes
Fuel Burn lb/hr 4,250 4,500 3,841 Yes
Emissions(NOx) g/kN thrust 15 (-75%) 22 21.1(-74.6%) No
Noise (Cumulative)
dB -42 -32 -27 No
60
Design Requirements Plausible?
Fuel Burn ~ Possible Field Length ~ Possible Emissions ~ Very difficult but can be
possible Noise ~ Not possible for N+2
Noise shieldingEngine configuration
61
Future Work
More detailed sizing code/calculations
Aircraft ModelBuild 3-D model
Work with airlines to receive feedback
Enter NASA competition