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Logan Waddell Morgan Buchanan Erik Susemichel Aaron Foster. Asgard Aviation System Definition Review. Craig Wikert Adam Ata Li Tan Matt Haas. Outline. Mission Statement Major Design Requirements Concept Selection Overview Pugh’s method Advanced Technologies - PowerPoint PPT Presentation
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ASGARD AVIATION SYSTEM DEFINITION
REVIEWLogan WaddellMorgan BuchananErik SusemichelAaron Foster
Craig WikertAdam AtaLi TanMatt Haas
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Outline Mission Statement Major Design Requirements Concept Selection
Overview Pugh’s method
Advanced Technologies Technologies incorporated Impact on sizing
Propulsion Selection Constraint Analysis
Major performance constraints Basic assumptions Constraint diagrams
Sizing Studies Design Mission Current Sizing Approach
Initial center of gravity, stability and control estimates Summary
3
Mission Statement
To design an environmentally responsibleaircraft 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 40% 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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Design Mission
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Aircraft Concept Selection
Eight Initial Concepts Pugh’s Method Two Result Concepts
Aircraft Concepts1 2 3
4 5 6
7 8
Pugh’s Method Process
• Eight designs were generated and sketched.• A baseline concept was chosen to be the reference or datum.• Each design was evaluated for each criterion
• Each design was assigned a ‘+’,’-’, or ‘s’ based from the datum.• All criteria was equally weighted.
• The ‘+’,’-’, and ‘s’ were totaled• The two concepts with the most ‘+’ were discussed and chosen• A second Pugh’s method was run with a different concept being the datum.• The results were collected as with the first run.• Two concepts were selected for further investigation.
Pugh’s Method (1st run)
DATUM
DATUM
Pugh’s Method (2nd run)
Concept Selection• Both concepts had best results from Pugh’s Method
•Tube and Wing design with advanced technologies
• Tube and Wing design• “H-tail” with two engines mounted in-
between• Swept back wings• Noise shielding• Technologies
• Winglets• Laminar Flow• Efficient Engine• Composite
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1
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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 Seating
No First Class (Low Cost Carriers)44 rows Economy
Class303 passengers
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Economy Class Section View
Fuselage Height = 16.5 feet
Aisle Height = 6.5 feet
Head Room = 5.5 feet
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1st Class Section View Seat Width = 23
inches
Cargo Area = 5 feet
Advanced TechnologySpiroid WingletsPros:• 6-10% reduction in fuel consumption (GII)• Improved climb gradient• Reduced climb thrust
• 3% derate (737-300), resulting in reduction of the noise footprint by 6.5% and NOx emissions by 5% (blended)
• Reduced cruise thrust • Improved cruise performance
• Direct climb• Good looks
Cons:• Additional weight > 1000lbs• Could distort under loads causing performance loss or aerodynamic problems• Complexity to manufacture• Unknown effects during icing conditions
Aviation Week & Space Technology, August 2, 2010. "Head Turning Tip" by William Garvey, "Inside Business Aviation" column, p60. http://www.b737.org.uk/winglets.htmhttp://www.aviationpartners.com/future.html
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Composite Materials 100 % Composite Aircraft
Lighter weight and stronger than Aluminum Modeled as 20% reduction in empty weight
Additional Benefits of Composite Materials Corrosion and fatigue benefits Reduce the amount of fasteners needed Composites used in acoustic damping Thermal transfer system Extended laminar flow
Disadvantages High costs Difficult crack detection
*http://www.designnews.com/article/14313-Boeing_787_Dreamliner_Represents_Composites_Revolution.php
*Boeing
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Advanced TechnologyLanding Gear Fairings Reduces the noise in the mid and high frequency
domain compared to the plain landing gear configuration up to 4.5 dB*
Reduces vortex shedding due to bluff-body nature of nose and main landing gear**
Modeled as increase in empty weight
*Molin, N. (2010). Perforated Fairings for Landing Gear Noise Control. Retrieved from eprints.soton.ac.uk: http://eprints.soton.ac.uk/43011/1/paper_vancouver_noabsolute_small.pdf** Bruner, D. S. (2010). N + 3 Phase I Final Review. NASA ERA (p. 94). Northrop Grumman.
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Hybrid Laminar Flow Control Active drag reduction technique Applied to wing, tail surfaces, and nacelles
can achieve a 15% drag reduction* Reduces fuel by ~ 5%** Increases cost of maintenance by ~ 2.8%** Increases DOC by ~0.8%** Increase in empty weight
*Clean Sky
*Archambaud, D. A. (2007). Laminar-Turbulent Transition Control. 2.** Joslin, R. D. (1998). Overview of Laminar Flow Control. NASA (p. 18). Langley Research Center.
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Engine Selection Engine type: Geared Turbofan Gearbox allows fan to run at lower speeds than
compressor and turbine, improving efficiency. Provides 12%-15% improvement in fuel burn
range, 50% NOx emissions reduction, and 20 dB decrease from level 4 noise standards
Courtesy of Tosaka Courtesy of Airliners.net
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Engine Sizing Approach Using NASA Geared Turbofan data to
approximate baseline performance of engine
Plan to use data to find fuel flow and SFC curve fit predictions as function of Mach #, altitude, and throttle setting
Will need to use adjustment factors to size engine to thrust requirements of aircraft
Also adjustment factors for implemented technologies will also need to be incorporated
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Engine Sizing cont.
Concept Aircraft MTOW (lbs) # of engines Max SLS Thrust (lbf) Scale Factor
Baseline CS300ER 139,600 2 23,369 n/a
2 H-Tail 273,000 2 45,701 1.96
3 Double Fuselage 300,000 2 50,220 2.15
4 Strut-Based High Wing 280,000 2 46,872 2.01
ሺ𝑻𝑺𝑳𝑺ሻ𝒓𝒖𝒃𝒃𝒆𝒓 = (𝑾𝝋 )𝒓𝒖𝒃𝒃𝒆𝒓 [ሺ𝑻𝑺𝑳𝑺ሻ𝒃𝒂𝒔𝒆𝒍𝒊𝒏𝒆(𝑾𝝋 )𝒃𝒂𝒔𝒆𝒍𝒊𝒏𝒆]𝒏𝒆𝒏𝒈𝒊𝒏𝒆 𝑺𝑭= 𝑻𝑺𝑳𝑺
ሺ𝑻𝑺𝑳𝑺ሻ𝒃𝒂𝒔𝒆𝒍𝒊𝒏𝒆
Compared aircraft concepts to Bombardier C-series airplane that will be powered by Pratt & Whitney GTF engines
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Technologies for Improvement Orbiting Combustion Nozzle (R-Jet Engineering) Combustor employs rotating blades inside inner casing Uses 25% less fuel and cuts CO2 and NOx emissions
by 75% Reduces size and weight of engine while producing
same thrust
24
Technologies cont. Noise Reduction Technologies
Swept/Leaned StatorsScarf InletChevron Nozzle
Images Courtesy of NASA Research
25
Technologies cont. Liquid Hydrogen Fuel
Provides more energy and reduces fuel weightCombustion of LH2 :
○ H2 + O2 + N2 = H2O + N2 + NOx
○ No CO2 emissions/lower NOx emissionsDrawbacks:
○ Fuel must be stored in cryogenic tank○ Added tank structure could cause fuselage to be
less aerodynamic Jet A LH2
density 840 kg/m^3 67.8 kg/m^3
specific energy 48.2 MJ/kg 143 MJ/kg
autoignition temp 210 C 571 C
26
Constraint Analysis & Diagrams Performance Constraints Basic Assumptions Constraint Diagrams
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Major Performance Constraint Analysis
top of climb (1g steady, level flight, M = 0.8 @ h=35K, service ceiling)
landing braking ground roll @ h = 5K, +15° hot day
second segment climb gradient above h = 5K, +15° hot day
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Updates Since SRR Conventional with New Technologies
Parameters SRR SDRAspect Ratio 8 7.8
Parasite Drag 0.01 0.016
CL max 1.9 (take off) 2.3 (land) 1.65 (take off) 1.9 (land)L/D max 3.1 17.2Take-off Ground Roll 3,348 ft 4,500 ftLanding Ground Roll 1,500 ft 2,000 ft
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Basic Assumption for Concept 1 Conventional with New TechnologiesMajor Constraints AssumptionsAspect Ratio 7.8
Parasite Drag (CD0) 0.016
Engine Lapse Rate/SFC 0.374
Oswald Efficiency Factor 0.8
Flight Velocity Cruise:0.8 M; Take-Off: 145 ktas; Landing: 135 ktas; Stall: 110 ktas
CL max 1.65 (take off) 1.9 (land)
Take-off Ground Roll 4.500 ft
Landing Ground Roll 2,000 ft
L/D max 17.2
We/W0 0.474
Cruise Altitude 35,000 ft
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Constraint Diagrams for Concept 1
TSL/W0
=0.32
W0/S =106 [lb/ft2]
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Updates Since SRR Conventional H-tail with Engines
Mounted in Between
Parameters SRR SDRAspect Ratio 8 7.8
Parasite Drag 0.015 0.02
CL max 2 (take off) 2.4 (land) 1.8 (take off) 2 (land)L/D max 4.1 18Take-off Ground Roll 3,000 ft 3,500 ftLanding Ground Roll 1,550 ft 1,700 ft
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Basic Assumption for Concept 2 Conventional H-tail with Engines Mounted in Between
Major Constraints AssumptionsAspect Ratio 7.8
Parasite Drag (CD0) 0.02
Engine Lapse Rate/SFC 0.374
Oswald Efficiency Factor 0.8
Flight Velocity Cruise:0.8 M; Take-Off: 155 ktas; Landing: 140 ktas; Stall: 110 ktas
CL max 1.8 (take off) 2 (land)
Take-off Ground Roll 3,500 ft
Landing Ground Roll 1,700 ft
L/D max 18
We/W0 0.474
Cruise Altitude 35,000 ft
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Constraint Diagrams for Concept 2
TSL/W0
=0.35
W0/S =98 [lb/ft2]
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Trade Studies of Performance Requirements
Trade Studies are ongoing Current Trade-offs
Conventional with New Technologies
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 Conventional H-tail with Engines Mounted in Between
Improved Control at Low Airspeed and Taxiing vs. More Drags Smaller Vertical Stabilizer vs. Heavier Horizontal Tail
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Sizing Code Incorporation Using NASA Geared Turbofan data to
approximate baseline performance of engine
Plan to use data to find fuel flow and SFC curve fit predictions as function of Mach #, altitude, and throttle setting
Will need to use adjustment factors to size engine to thrust requirements of aircraft
Also adjustment factors for implemented technologies will also need to be incorporated
36
Sizing Code Using MATLAB
software, first order method from Raymer
Used several inputs to determine the size of pre-existing aircraft for validation
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Status of Sizing Code Currently the code calculates
coefficients of lift and drag needed for fuel burn predictions
Future work needed includes the component weight build up
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Incorporating Drag Drag values affect
the sizing and are necessary in order to predict the takeoff weight
Included in the equation are the parasitic, induced, and wave drag
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Validation Boeing 767-200ER
Passenger Capacity: 224
Range: 6,545 nmiCrew: 2Cruise Mach: 0.8Max Fuel Capacity:
16,700 gal
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Validation continued
Actual Prediction % Error
Gross Takeoff Weight
395,000 [lb] 421,170 [lb] 6.63
Empty Weight Fraction
.46684 .45925 1.63
The sizing code predictions are accurate
The error factor for the takeoff weight is:
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Selected Concept Predictions
Tube and wing with H-Tail
Take Off Gross Weight[lb]
Empty Weight Fraction
Wempty
[lb]Wfuel
[lb]Wpayload
[lb]Wcrew
[lb]
266239 .474 126267 83572 55000 1400
Tube and wing with new technology
Take Off Gross Weight[lb]
Empty Weight Fraction
Wempty
[lb]Wfuel
[lb]Wpayload
[lb]Wcrew
[lb]
269895 .474 127918 85577 55000 1400
L/Dcruise = 17.2, AR = 7.8
L/Dcruise = 16.9, AR = 7.8
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Center of Gravity, Stability, and Control Estimates
Center of Gravity
Neutral Point
Tube and Wing Tube and Wing aft engines
CG ~ 55% of fuselage CG ~ 70% of fuselage
SM ~10% SM: ~ 5 %
43
Tail Sizing Current Approach
Using Raymer Equations (6.28) and (6.29)
Concept 1 Concept 2Tail area 815 ft2 1100 ft2
Vertical Tail area 660 ft2 600 ft2
Concept 1
•Length: 180’ 180’ 3’’ •Wing Span: 157’ 156’ 1’’•Height: 51’ 51’•Fuselage Height: 17’ 17’ 9’’•Fuselage Width: 16’ 16’ 6’’
Concept 2 767-300
Concept 2
•Length: 180’ 180’ 3’’ •Wing Span: 165’ 156’ 1’’•Height: 45’ 51’•Fuselage Height: 17’ 17’ 9’’•Fuselage Width: 16’ 16’ 6’’
767-300Concept 1
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Design Requirements
Requirement Unit Target Threshold
Conventional a/c with new
Tech Compliant
conventional a/c with H-
Tail, aft engines
Range naut. miles 4000 3600 3900 Yes 3800 Yes
Payload pax 250 230 250 Yes 250 Yes
Cruise Mach # - 0.8 0.72 0.8 Yes 0.8 Yes
Take Off Ground Roll ft 7000 9000 4500 Yes 3500 Yes
Landing Ground Roll ft 6000 6500 2000 Yes 1700 Yes
Emissions g/kN thrust 15 22 - N/A - N/A
Noise (Cum.) dB -42 -32 - N/A - N/A
Compliance Matrix
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Next Steps Finalize Sizing Code Complete Component Weights Determine Aircraft details
NoiseCostStability and Control