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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
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Logan Waddell Morgan Buchanan Erik Susemichel Aaron Foster Asgard AviationSystem Definition Review Craig Wikert Adam Ata Li Tan Matt Haas
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
Mission Statement To design an environmentally responsible aircraft that sufficiently completes the “N+2” requirements for the NASA green aviation challenge.
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
Aircraft Concept Selection • Eight Initial Concepts • Pugh’s Method • Two Result Concepts
Aircraft Concepts 1 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
Concept Selection • Both concepts had best results from Pugh’s Method 1 • 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 2
Two Class System • Seating • 4 rows 1st Class • 34 rows Economy Class • 250 passengers • Seat Pitch • 39 inches 1st Class • 34 inches Economy Class • Seat Width • 23 inches 1st Class • 19 inches Economy Class
One Class System • Seating • No First Class (Low Cost Carriers) • 44 rows Economy Class • 303 passengers
Economy Class Section View • Fuselage Height = 16.5 feet • Aisle Height = 6.5 feet • Head Room = 5.5 feet
1st Class Section View • Seat Width = 23 inches • Cargo Area = 5 feet
Advanced Technology Spiroid Winglets • Pros: • 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.htm http://www.aviationpartners.com/future.html
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 *Boeing *http://www.designnews.com/article/14313-Boeing_787_Dreamliner_Represents_Composites_Revolution.php
Advanced Technology Landing 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.
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 *Archambaud, D. A. (2007). Laminar-Turbulent Transition Control. 2. ** Joslin, R. D. (1998). Overview of Laminar Flow Control. NASA (p. 18). Langley Research Center. *Clean Sky
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
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
Engine Sizing cont. • Compared aircraft concepts to Bombardier C-series airplane that will be powered by Pratt & Whitney GTF engines
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
Technologies cont. • Noise Reduction Technologies • Swept/Leaned Stators • Scarf Inlet • Chevron Nozzle Images Courtesy of NASA Research
Technologies cont. • Liquid Hydrogen Fuel • Provides more energy and reduces fuel weight • Combustion of LH2 : • H2 + O2 + N2 = H2O + N2 + NOx • No CO2 emissions/lower NOx emissions • Drawbacks: • Fuel must be stored in cryogenic tank • Added tank structure could cause fuselage to be less aerodynamic
Constraint Analysis & Diagrams • Performance Constraints • Basic Assumptions • Constraint Diagrams
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
Updates Since SRR • Conventional with New Technologies
Basic Assumption for Concept 1Conventional with New Technologies
Constraint Diagrams for Concept 1 TSL/W0 =0.32 W0/S =106 [lb/ft2]
Updates Since SRR • Conventional H-tail with Engines Mounted in Between
Basic Assumption for Concept 2Conventional H-tail with Engines Mounted in Between
Constraint Diagrams for Concept 2 TSL/W0 =0.35 W0/S =98 [lb/ft2]
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
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
Sizing Code • Using MATLAB software, first order method from Raymer • Used several inputs to determine the size of pre-existing aircraft for validation
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
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
Validation • Boeing 767-200ER • Passenger Capacity: 224 • Range: 6,545 nmi • Crew: 2 • Cruise Mach: 0.8 • Max Fuel Capacity: 16,700 gal
Validation continued • The sizing code predictions are accurate • The error factor for the takeoff weight is:
Selected Concept Predictions Tube and wing with new technology L/Dcruise = 17.2, AR = 7.8 Tube and wing with H-Tail L/Dcruise = 16.9, AR = 7.8
Center of Gravity, Stability, and Control Estimates Center of Gravity Neutral Point
Tail Sizing • Current Approach • Using Raymer Equations (6.28) and (6.29)
Concept 1 Concept 2 767-300 • Length: 180’ 180’ 3’’ • Wing Span: 157’ 156’ 1’’ • Height: 51’ 51’ • Fuselage Height: 17’ 17’ 9’’ • Fuselage Width: 16’ 16’ 6’’
Concept 2 Concept 1 767-300 • Length: 180’ 180’ 3’’ • Wing Span: 165’ 156’ 1’’ • Height: 45’ 51’ • Fuselage Height: 17’ 17’ 9’’ • Fuselage Width: 16’ 16’ 6’’
Design Requirements Compliance Matrix
Next Steps • Finalize Sizing Code • Complete Component Weights • Determine Aircraft details • Noise • Cost • Stability and Control