Logan Waddell Morgan Buchanan Erik Susemichel Aaron Foster Craig Wikert Adam Ata Li Tan Matt Haas 1

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 2

Mission Statement To design an environmentally responsible aircraft that sufficiently completes the “N+2” requirements for the NASA green aviation challenge. 3

Major Design Requirements  Noise (dB) 42 dB decrease in noise  NO x Emissions 75% reduction in emissions below CAEP 6  Aircraft Fuel Burn 40% Reduction in Fuel Burn  Airport Field Length 50% shorter distance to takeoff * 4 *ERA. (n.d.). Retrieved 2011, from NASA:

Design Mission 5

Aircraft Concept Selection  Eight Initial Concepts  Pugh’s Method  Two Result Concepts 6

Aircraft Concepts

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 (1 st run)

Pugh’s Method (2 nd 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 2 1

Two Class System  Seating 4 rows 1 st Class 34 rows Economy Class 250 passengers  Seat Pitch 39 inches 1 st Class 34 inches Economy Class  Seat Width 23 inches 1 st Class 19 inches Economy Class 12

One Class System  Seating No First Class (Low Cost Carriers) 44 rows Economy Class 303 passengers 13

Economy Class Section View  Fuselage Height = 16.5 feet  Aisle Height = 6.5 feet  Head Room = 5.5 feet 14

1 st Class Section View  Seat Width = 23 inches  Cargo Area = 5 feet 15

Advanced Technology Spiroid Winglets Pros: 6-10% reduction in fuel consumption (GII) Improved climb gradient Reduced climb thrust 3% derate ( ), 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, "Head Turning Tip" by William Garvey, "Inside Business Aviation" column, p

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 17 * *Boeing

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 18 *Molin, N. (2010). Perforated Fairings for Landing Gear Noise Control. Retrieved from eprints.soton.ac.uk: ** 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 19 *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.

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 20 Courtesy of TosakaCourtesy 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 21

Engine Sizing cont. ConceptAircraftMTOW (lbs)# of enginesMax SLS Thrust (lbf)Scale Factor BaselineCS300ER139,600223,369n/a 2H-Tail273,000245, Double Fuselage300,000250, Strut-Based High Wing280,000246,  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 23

Technologies cont.  Noise Reduction Technologies Swept/Leaned Stators Scarf Inlet Chevron Nozzle 24 Images Courtesy of NASA Research

Technologies cont.  Liquid Hydrogen Fuel Provides more energy and reduces fuel weight Combustion of LH 2 : ○ H 2 + O 2 + N 2 = H 2 O + N 2 + NO x ○ No CO2 emissions/lower NOx emissions Drawbacks: ○ Fuel must be stored in cryogenic tank ○ Added tank structure could cause fuselage to be less aerodynamic 25 Jet ALH2 density840 kg/m^367.8 kg/m^3 specific energy48.2 MJ/kg143 MJ/kg autoignition temp210 C571 C

Constraint Analysis & Diagrams  Performance Constraints  Basic Assumptions  Constraint Diagrams 26

Major Performance Constraint Analysis  top of climb (1g steady, level flight, M = h=35K, service ceiling)  landing braking ground h = 5K, +15° hot day  second segment climb gradient above h = 5K, +15° hot day 27

Updates Since SRR  Conventional with New Technologies 28 Parameters SRR SDR Aspect Ratio Parasite Drag CL max1.9 (take off) 2.3 (land)1.65 (take off) 1.9 (land) L/D max Take-off Ground Roll3,348 ft4,500 ft Landing Ground Roll1,500 ft2,000 ft

Basic Assumption for Concept 1 Conventional with New Technologies Major ConstraintsAssumptions Aspect Ratio7.8 Parasite Drag (CD0)0.016 Engine Lapse Rate/SFC0.374 Oswald Efficiency Factor0.8 Flight VelocityCruise:0.8 M; Take-Off: 145 ktas; Landing: 135 ktas; Stall: 110 ktas CL max1.65 (take off) 1.9 (land) Take-off Ground Roll4.500 ft Landing Ground Roll2,000 ft L/D max17.2 W e /W Cruise Altitude35,000 ft 29

Constraint Diagrams for Concept 1 30 T SL /W 0 =0.32 W 0 /S =106 [lb/ft 2 ]

Updates Since SRR  Conventional H-tail with Engines Mounted in Between 31 Parameters SRR SDR Aspect Ratio Parasite Drag CL max2 (take off) 2.4 (land)1.8 (take off) 2 (land) L/D max Take-off Ground Roll3,000 ft3,500 ft Landing Ground Roll1,550 ft1,700 ft

Basic Assumption for Concept 2 Conventional H-tail with Engines Mounted in Between Major ConstraintsAssumptions Aspect Ratio7.8 Parasite Drag (CD0)0.02 Engine Lapse Rate/SFC0.374 Oswald Efficiency Factor0.8 Flight VelocityCruise:0.8 M; Take-Off: 155 ktas; Landing: 140 ktas; Stall: 110 ktas CL max1.8 (take off) 2 (land) Take-off Ground Roll3,500 ft Landing Ground Roll1,700 ft L/D max18 W e /W Cruise Altitude35,000 ft 32

Constraint Diagrams for Concept 2 33 T SL /W 0 =0.35 W 0 /S =98 [lb/ft 2 ]

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 34

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 35

Sizing Code  Using MATLAB software, first order method from Raymer  Used several inputs to determine the size of pre- existing aircraft for validation 36

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 37

Incorporating Drag 38  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 ER Passenger Capacity: 224 Range: 6,545 nmi Crew: 2 Cruise Mach: 0.8 Max Fuel Capacity: 16,700 gal 39

Validation continued 40 ActualPrediction% Error Gross Takeoff Weight 395,000 [lb]421,170 [lb]6.63 Empty Weight Fraction  The sizing code predictions are accurate  The error factor for the takeoff weight is:

Selected Concept Predictions 41 Tube and wing with H-Tail Take Off Gross Weight [lb] Empty Weight Fraction W empty [lb] W fuel [lb] W payload [lb] W crew [lb] Tube and wing with new technology Take Off Gross Weight [lb] Empty Weight Fraction W empty [lb] W fuel [lb] W payload [lb] W crew [lb] L/D cruise = 17.2, AR = 7.8 L/D cruise = 16.9, AR = 7.8

Center of Gravity, Stability, and Control Estimates 42 Center of Gravity Neutral Point Tube and WingTube and Wing aft engines CG ~ 55% of fuselageCG ~ 70% of fuselage SM ~10%SM: ~ 5 %

Tail Sizing  Current Approach Using Raymer Equations (6.28) and (6.29) 43 Concept 1Concept 2 Tail area815 ft ft 2 Vertical Tail area660 ft ft 2

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

Concept 2 Length: 180’ 180’ 3’’ Wing Span: 165’ 156’ 1’’ Height: 45’ 51’ Fuselage Height: 17’ 17’ 9’’ Fuselage Width: 16’ 16’ 6’’ Concept 1

Design Requirements 46 RequirementUnitTargetThreshold Conventional a/c with new TechCompliant conventional a/c with H- Tail, aft engines Rangenaut. miles Yes3800Yes Payloadpax Yes250Yes Cruise Mach # Yes0.8Yes Take Off Ground Rollft Yes3500Yes Landing Ground Rollft Yes1700Yes Emissionsg/kN thrust1522-N/A- Noise (Cum.)dB N/A- Compliance Matrix

Next Steps  Finalize Sizing Code  Complete Component Weights  Determine Aircraft details Noise Cost Stability and Control 47